Pharmacology Toughest Exam Quiz!

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Pharmacology Toughest Exam Quiz! - Quiz



Questions and Answers
  • 1. 

    Pindolol and some other β adrenergic receptor antagonists have an additional property that is referred to as intrinsic sympathomimetic activity (ISA). This additional property indicates these agents are:

    • A.

      Full agonists

    • B.

      Inverse agonist

    • C.

      Neutral antagonists

    • D.

      Noncompetitive antagonists

    • E.

      Partial agonists

    Correct Answer
    E. Partial agonists
    Explanation
    Pindolol and some other β adrenergic receptor antagonists have intrinsic sympathomimetic activity (ISA), which means that they can partially activate the β adrenergic receptors. Unlike full agonists, which fully activate the receptors, and neutral antagonists, which have no effect on the receptors, partial agonists have a moderate level of activation. Therefore, Pindolol and other β adrenergic receptor antagonists with ISA can partially activate the receptors while still blocking the effects of other agonists.

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  • 2. 

    A 28-year-old woman is brought to the emergency department after overdosing on oxycodone, an opiate analgesic. She is unconscious and barely breathing when she arrives at the hospital, but revives and is breathing normally within 2 minutes after receiving an injection of naloxone. After about an hour, she requires another dose of naloxone as the symptoms of opiate overdose begin to redevelop. Naloxone is likely acting as a:

    • A.

      Strong stimulant that counteracts the CNS-depressant effects of the opiate.

    • B.

      Diuretic that increases renal excretion of the opiate.

    • C.

      Drug that stimulates respiratory centers in the brain.

    • D.

      Competitive antagonist of opioid receptors.

    • E.

      Noncompetitive antagonist of opioid receptors.

    Correct Answer
    D. Competitive antagonist of opioid receptors.
    Explanation
    Naloxone is a competitive antagonist of opioid receptors. Opioid receptors are the targets of opioids like oxycodone, and naloxone competes with these opioids for binding to the receptors. By binding to the receptors, naloxone blocks the effects of the opioids, reversing their depressant effects on the central nervous system. This explains why the woman revives and begins breathing normally after receiving naloxone. However, since naloxone has a shorter half-life than oxycodone, the symptoms of opiate overdose start to redevelop after some time, requiring another dose of naloxone.

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  • 3. 

    The therapeutic window is an indication of the:

    • A.

      Length of time a drug should be administered to achieve optimal effects

    • B.

      Time of day when a drug should be administered or optimal effects

    • C.

      Range of concentrations over which a drug is maximally effective for all patients

    • D.

      Range of concentrations over which a drug is safe and efficacious for most patients

    • E.

      Age range of patients that is optimal for a given drug

    Correct Answer
    D. Range of concentrations over which a drug is safe and efficacious for most patients
    Explanation
    The therapeutic window refers to the range of concentrations at which a drug is both safe and effective for most patients. This means that the drug is within the desired therapeutic range, where it can produce the desired therapeutic effects without causing significant adverse effects. It is important to monitor drug concentrations within this window to ensure optimal treatment outcomes.

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  • 4. 

    Preclinical characterization of a new drug indicates that it is an inverse agonist for adenosine receptors. It interacts syntopically with adenosine. In the presence of adenosine, this drug will behave like a(n):

    • A.

      Full agonist with additive effects to adenosine at high concentrations

    • B.

      Partial agonist with additive effects to adenosine at high concentrations

    • C.

      Partial agonist with inhibitory effects to adenosine at high concentrations

    • D.

      Inert compound with no additive or inhibitory effects to adenosine at high concentrations

    • E.

      Competitive antagonist with inhibitory effects on receptor activation

    Correct Answer
    E. Competitive antagonist with inhibitory effects on receptor activation
    Explanation
    Based on the information provided, the drug is described as an inverse agonist for adenosine receptors, meaning it has an opposite effect to adenosine. Therefore, in the presence of adenosine, the drug will act as a competitive antagonist, inhibiting the activation of the receptor. This indicates that the drug will have inhibitory effects on receptor activation, making the correct answer "competitive antagonist with inhibitory effects on receptor activation."

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  • 5. 

    The term “first-pass effect” refers to the

    • A.

      Effect a new drug has on the body after its first administration.

    • B.

      Time it takes for a drug to be detected in the urine or feces after oral administration.

    • C.

      Ability of the intestines and liver to reduce the bioavailability of a drug.

    • D.

      Time it takes for a drug to reach therapeutic concentrations in the target tissue.

    • E.

      Initial effect a drug has on target tissues.

    Correct Answer
    C. Ability of the intestines and liver to reduce the bioavailability of a drug.
    Explanation
    The term "first-pass effect" refers to the ability of the intestines and liver to reduce the bioavailability of a drug. This means that after oral administration of a drug, the drug may undergo metabolism and elimination in the intestines and liver before it can reach systemic circulation and exert its therapeutic effects. This can result in a lower concentration of the drug reaching the target tissues, reducing its effectiveness.

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  • 6. 

    The term “blood-brain barrier” (BBB) refers to a:

    • A.

      Noncellular barrier that prevents drugs from entering the CNS unless transported by specific carriers.

    • B.

      Cellular barrier that includes brain capillary endothelial cells that limits drug entry into the brain.

    • C.

      Virtual or conceptual barrier that can explain the behavior of some drug effects on the CNS.

    • D.

      Physical barrier that prevents blood from entering the brain.

    • E.

      Device that is used to prevent blood-borne drugs from entering the brain

    Correct Answer
    B. Cellular barrier that includes brain capillary endothelial cells that limits drug entry into the brain.
    Explanation
    The term "blood-brain barrier" refers to a cellular barrier that includes brain capillary endothelial cells that limits drug entry into the brain. This barrier is formed by tight junctions between the endothelial cells of the brain capillaries, which prevents the free diffusion of drugs and other substances from the blood into the brain. Only certain molecules that are transported by specific carriers can cross this barrier and enter the central nervous system.

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  • 7. 

    Phase 1 drug metabolism differs from phase 2 metabolism in that:

    • A.

      Phase 1 metabolism always occurs prior to phase 2 metabolism.

    • B.

      Phase 1 metabolism occurs in the intestine where orally administered drugs can first be metabolized, whereas phase 2 metabolism occurs in the blood.

    • C.

      Phase 1 metabolism occurs in the liver soon after a drug is absorbed, whereas phase 2 metabolism occurs after a drug is excreted into the urine.

    • D.

      Phase 1 metabolic enzymes activate prodrugs, whereas phase 2 metabolic enzymes inactivate drugs.

    • E.

      Phase 1 metabolic reactions functionalize drugs, whereas phase 2 metabolic reactions conjugate drugs.

    Correct Answer
    E. Phase 1 metabolic reactions functionalize drugs, whereas phase 2 metabolic reactions conjugate drugs.
    Explanation
    Phase 1 drug metabolism and phase 2 drug metabolism are two distinct processes. Phase 1 metabolic reactions involve the functionalization of drugs, which can include processes such as oxidation, reduction, and hydrolysis. These reactions often result in the formation of more polar and water-soluble metabolites. In contrast, phase 2 metabolic reactions involve the conjugation of drugs with endogenous compounds, such as glucuronic acid, sulfate, or amino acids. This conjugation process further increases the water solubility of the drugs, facilitating their elimination from the body through urine or bile. Therefore, phase 1 metabolism functionalizes drugs, while phase 2 metabolism conjugates drugs.

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  • 8. 

    The most important pharmacokinetic concept to consider when designing a rational long-term pharmacotherapy is

    • A.

      Bioavailability.

    • B.

      Route of administration.

    • C.

      Volume of distribution.

    • D.

      Clearance.

    • E.

      Elimination t1/2

    Correct Answer
    D. Clearance.
    Explanation
    Clearance is the most important pharmacokinetic concept to consider when designing a rational long-term pharmacotherapy because it determines the rate at which a drug is removed from the body. Clearance is the volume of plasma cleared of the drug per unit of time, and it is influenced by factors such as liver and kidney function. Understanding clearance is crucial in determining the appropriate dosage and dosing interval to maintain therapeutic drug levels over an extended period of time.

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  • 9. 

    A drug that is a weak acid (pKa = 5) is largely excreted unchanged by the kidneys. To increase its rate of excretion

    • A.

      The pH of the urine should be increased.

    • B.

      The pH of the urine should be decreased.

    • C.

      The pH of the urine should be left unchanged.

    • D.

      CYP liver enzymes should be induced to increase metabolism of the drug.

    • E.

      The patient should drink more water to increase urine output.

    Correct Answer
    A. The pH of the urine should be increased.
    Explanation
    To increase the rate of excretion of a weak acid drug, the pH of the urine should be increased. This is because weak acids are more ionized in alkaline conditions. When the pH of the urine is increased, the weak acid drug will become more ionized, making it less likely to be reabsorbed by the renal tubules and more likely to be excreted in the urine. Therefore, increasing the pH of the urine will enhance the elimination of the drug from the body.

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  • 10. 

    A 3-year-old is brought to the emergency department having just ingested a large overdose of tolbutamide, an oral antidiabetic drug. Tolbutamide is a weak acid with a pKa of 5.3. It is capable of entering most tissues, including the brain. On physical examination, the heart rate is 100/min, blood pressure 90/50 mm Hg, and respiratory rate 20/min. Which of the following statements about this case of tolbutamide overdose is most correct?  

    • A.

      Urinary excretion would be accelerated by administration of NH4Cl, an acidifying agent

    • B.

      Urinary excretion would be accelerated by giving NaHCO3, an alkalinizing agent

    • C.

      Less of the drug would be ionized at blood pH than at stomach pH

    • D.

      Absorption of the drug would be slower from the stomach than from the small intestine  

    • E.

      Hemodialysis is the only effective therapy

    Correct Answer
    B. Urinary excretion would be accelerated by giving NaHCO3, an alkalinizing agent
    Explanation
    Tolbutamide is a weak acid, and weak acids are more likely to be excreted in the urine when the urine is alkaline. By giving NaHCO3, an alkalinizing agent, the pH of the urine will increase, promoting the excretion of the drug. This is the most correct statement because it aligns with the pharmacokinetics of weak acids. The other options are not correct because NH4Cl would acidify the urine, which would decrease excretion, less of the drug would be ionized at blood pH than at stomach pH, and the absorption of the drug would not be affected by the pH of the stomach or small intestine. Hemodialysis may be considered in severe cases, but it is not the only effective therapy.

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  • 11. 

    Botulinum toxin is a large protein molecule. Its action on cholinergic transmission depends on an intracellular action within nerve endings. Which one of the following processes is best suited for permeation of very large protein molecules into cells?

    • A.

      Aqueous diffusion

    • B.

      Endocytosis

    • C.

      First-pass effect

    • D.

      Lipid diffusion

    • E.

      Special carrier transport

    Correct Answer
    B. Endocytosis
    Explanation
    Endocytosis is the process by which cells engulf large molecules or particles by forming a vesicle around them and bringing them into the cell. This process is best suited for the permeation of very large protein molecules into cells because it allows the protein to be enclosed within a vesicle and transported across the cell membrane. Aqueous diffusion, lipid diffusion, and special carrier transport are not suitable for large protein molecules, as they are primarily used for smaller molecules. The first-pass effect refers to the metabolism of drugs in the liver before they reach the systemic circulation and is not relevant to the permeation of protein molecules into cells.

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  • 12. 

    A 12-year-old child has bacterial pharyngitis and is to receive an oral antibiotic. She complains of a sore throat and pain on swallowing. The tympanic membranes are slightly reddened bilaterally, but she does not complain of earache. Blood pressure is 105/70 mm Hg, heart rate 100/mm, temperature 37.8 °C (100.1 °F). Ampicillin is a weak organic acid with a pKa of 2.5. What percentage of a given dose will be in the lipid-soluble form in the duodenum at a pH of 4.5?

    • A.

      About 1%

    • B.

      About 10%

    • C.

      About 50%

    • D.

      About 90%

    • E.

      About 99%

    Correct Answer
    A. About 1%
  • 13. 

    Ampicillin is eliminated by first-order kinetics. Which of the following statements best describes the process by which the plasma concentration of this drug declines?

    • A.

      There is only 1 metabolic path for drug elimination

    • B.

      The half-life is the same regardless of the plasma concentration

    • C.

      The drug is largely metabolized in the liver after oral administration and has low bioavailability

    • D.

      The rate of elimination is proportional to the rate of administration at all times

    • E.

      The drug is distributed to only 1 compartment outside the vascular system.

    Correct Answer
    B. The half-life is the same regardless of the plasma concentration
    Explanation
    The half-life of a drug refers to the time it takes for the concentration of the drug in the plasma to decrease by half. In this case, the statement that the half-life is the same regardless of the plasma concentration suggests that the rate of elimination of Ampicillin remains constant over time. This indicates that Ampicillin follows first-order kinetics, where the rate of elimination is proportional to the drug concentration. Therefore, as the drug concentration decreases, the rate of elimination also decreases, resulting in a consistent half-life.

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  • 14. 

    The pharmacokinetic process or property that distinguishes the elimination of ethanol and high doses of phenytoin and aspirin from the elimination of most other drugs is called

    • A.

      Distribution

    • B.

      Excretion

    • C.

      First-pass effect

    • D.

      First-order elimination

    • E.

      Zero-order elimination

    Correct Answer
    E. Zero-order elimination
    Explanation
    Zero-order elimination is the pharmacokinetic process or property that distinguishes the elimination of ethanol and high doses of phenytoin and aspirin from the elimination of most other drugs. In zero-order elimination, the rate of elimination remains constant regardless of the concentration of the drug in the body. This is different from first-order elimination, where the rate of elimination is proportional to the drug concentration. Zero-order elimination is typically seen when the elimination pathways for the drug become saturated at higher doses, resulting in a constant rate of elimination.

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  • 15. 

    A new drug was administered intravenously, and its plasma levels were measured for several hours. A graph was prepared as shown below, with the plasma levels plotted on a logarithmic ordinate and time on a linear abscissa. It was concluded that the drug has first-order kinetics. From this graph, what is the best estimate of the half-life?

    • A.

      0.5h

    • B.

      1h

    • C.

      3h

    • D.

      4h

    • E.

      7h

    Correct Answer
    C. 3h
    Explanation
    The best estimate of the half-life can be determined by finding the time it takes for the plasma levels to decrease by half. In the given graph, it can be observed that the plasma levels decrease by half at around 3 hours. Therefore, the best estimate of the half-life is 3 hours.

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  • 16. 

    A large pharmaceutical company has conducted extensive animal testing of a new drug for the treatment of advanced prostate cancer. The chief of research and development recommends that the company now submit an IND application in order to start clinical trials. Which of the following statements is most correct regarding clinical trials of new drugs?

    • A.

      Phase 1 involves the study of a small number of normal volunteers by highly trained clinical pharmacologists

    • B.

      Phase 2 involves the use of the new drug in a large number of patients (1000–5000) who have the disease to be treated under conditions of proposed use (eg, outpatients)

    • C.

      Chronic animal toxicity studies must be complete and reported in the IND

    • D.

      Phase 4 involves the detailed study of toxic effects that have been discovered in phase 3

    • E.

      Phase 2 requires the use of a positive control (a known effective drug) and a placebo.

    Correct Answer
    A. Phase 1 involves the study of a small number of normal volunteers by highly trained clinical pharmacologists
    Explanation
    Phase 1 of clinical trials involves studying a small number of normal volunteers under the supervision of highly trained clinical pharmacologists. This phase is focused on assessing the safety and dosage of the new drug in humans. It helps determine the drug's pharmacokinetics, pharmacodynamics, and potential side effects. The goal is to gather preliminary data on the drug's safety profile and establish a safe dosage range for further testing. This phase is crucial in determining whether the drug can progress to the next phases of clinical trials.

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  • 17. 

    Which of the following statements about the testing of new compounds for potential therapeutic use in the treatment of hypertension is most correct?

    • A.

      Animal tests cannot be used to predict the types of clinical toxicities that may occur because there is no correlation with human toxicity

    • B.

      Human studies in normal individuals will be done before the drug is used in individuals with hypertension

    • C.

      The degree of risk must be assessed in at least 3 species of animals, including 1 primate species

    • D.

      The animal therapeutic index must be known before trial of the agents in humans

    Correct Answer
    B. Human studies in normal individuals will be done before the drug is used in individuals with hypertension
    Explanation
    Before a new compound is used in individuals with hypertension, human studies in normal individuals will be conducted. This is because it is important to first understand the safety and effectiveness of the compound in a controlled setting before testing it on individuals with the specific condition. By conducting studies in normal individuals, researchers can gather valuable information about the compound's potential therapeutic use and any potential risks or side effects. This helps to ensure the safety and efficacy of the compound before it is used in individuals with hypertension.

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  • 18. 

    Which of the following statements about new drug development is most correct?

    • A.

      Drugs that test positive for teratogenicity, mutagenicity, or carcinogenicity can be tested in humans

    • B.

      Food supplements and herbal (botanical) remedies are subject to the same FDA regulation as ordinary drugs

    • C.

      All new drugs must be studied in at least 1 primate species before NDA submission

    • D.

      Orphan drugs are drugs that are no longer produced by the original manufacturer

    • E.

      Phase 4 (surveillance) is the most rigidly regulated phase of clinical drug trials

    Correct Answer
    A. Drugs that test positive for teratogenicity, mutagenicity, or carcinogenicity can be tested in humans
  • 19. 

    A 55-year-old woman with hypertension is to be treated with a thiazide diuretic. Thiazide A in a dose of 5 mg produces the same decrease in blood pressure as 500 mg of thiazide B. Which of the following statements best describes these results?

    • A.

      Thiazide A is more efficacious than thiazide B

    • B.

      Thiazide A is about 100 times more potent than thiazide B

    • C.

      Toxicity of thiazide A is less than that of thiazide B

    • D.

      Thiazide A has a wider therapeutic window than thiazide B

    • E.

      Thiazide A has a longer half-life than thiazide B

    Correct Answer
    B. Thiazide A is about 100 times more potent than thiazide B
    Explanation
    The statement "Thiazide A is about 100 times more potent than thiazide B" best describes the results because it indicates that a much lower dose of Thiazide A (5 mg) produces the same decrease in blood pressure as a higher dose of Thiazide B (500 mg). This suggests that Thiazide A is more effective and has a greater potency than Thiazide B.

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  • 20. 

    Prior to clinical trials in patients with heart failure, an animal study was carried out to compare two new positive inotropic drugs (A and B) to a current standard agent (C). The results of cardiac output measurements are shown in the graph below. Which of the following statements is correct?

    • A.

      Drug A is most effective

    • B.

      Drug B is least potent

    • C.

      Drug C is most potent

    • D.

      Drug B is more potent than drug C and more effective than drug A

    • E.

      Drug A is more potent than drug B and more effective than drug C

    Correct Answer
    D. Drug B is more potent than drug C and more effective than drug A
    Explanation
    Based on the graph, the cardiac output for drug B is higher than drug C, indicating that drug B is more potent than drug C. Additionally, the cardiac output for drug A is lower than both drug B and drug C, suggesting that drug B is more effective than drug A. Therefore, the correct statement is "Drug B is more potent than drug C and more effective than drug A."

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  • 21. 

    A study was carried out in isolated intestinal smooth muscle preparations to determine the action of a new drug “novamine,” which in separate studies bound to the same receptors as acetylcholine. In the absence of other drugs, acetylcholine caused contraction of the muscle. Novamine alone caused relaxation of the preparation. In the presence of a low concentration of novamine, the EC50 of acetylcholine was unchanged, but the Emax was reduced. In the presence of a high concentration of novamine, extremely high concentrations of acetylcholine had no effect. Which of the following expressions best describes novamine?

    • A.

      A chemical antagonist

    • B.

      An irreversible antagonist

    • C.

      A partial agonist

    • D.

      A physiologic antagonist

    • E.

      A spare receptor agonist

    Correct Answer
    B. An irreversible antagonist
    Explanation
    Novamine is best described as an irreversible antagonist because it binds to the same receptors as acetylcholine and causes relaxation of the smooth muscle. In the presence of a low concentration of novamine, the effectiveness of acetylcholine is reduced (Emax is reduced), and in the presence of a high concentration of novamine, acetylcholine has no effect. This suggests that novamine irreversibly blocks the receptors, preventing acetylcholine from causing muscle contraction.

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  • 22. 

    Sugammadex is a new drug that reverses the action of rocuronium and certain other skeletal muscle-relaxing agents (nondepolarizing neuromuscular blocking agents). It appears to interact directly with the rocuronium molecule and not at all with the rocuronium receptor. Which of the following terms best describes sugammadex?

    • A.

      Chemical antagonist

    • B.

      Noncompetitive antagonist

    • C.

      Partial agonist

    • D.

      Pharmacologic antagonist

    • E.

      Physiologic antagonist

    Correct Answer
    A. Chemical antagonist
    Explanation
    Sugammadex is classified as a chemical antagonist because it directly interacts with the rocuronium molecule to reverse its action. It does not bind to the rocuronium receptor, making it different from a competitive or noncompetitive antagonist. It also does not have any agonistic activity, ruling out partial agonist. Sugammadex is a specific drug that acts chemically to counteract the effects of rocuronium, making it a chemical antagonist.

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  • 23. 

    A 42-year-old man has just been prescribed a new drug. After several doses he notices dry mouth, dry eyes, and a rapid heart rate. This is most likely due to an inhibition of which of the following neurotransmitter:

    • A.

      Norepinephrine

    • B.

      Serotonin

    • C.

      Glutamate

    • D.

      Acetylcholine

    • E.

      Epinephrine

    Correct Answer
    D. Acetylcholine
    Explanation
    The symptoms of dry mouth, dry eyes, and rapid heart rate are consistent with the side effects of anticholinergic drugs. Acetylcholine is a neurotransmitter that is involved in the regulation of various bodily functions including salivation, tear production, and heart rate. Inhibition of acetylcholine can lead to decreased production of saliva and tears, as well as an increased heart rate. Therefore, the most likely explanation for the symptoms experienced by the man is an inhibition of acetylcholine.

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  • 24. 

    A 23-year-old man is accosted by 3 men late at night. Immediately his heart rate increases due to an increase in epinephrine in his circulation. This release of epinephrine from the adrenal medulla is the result of the action of acetylcholine on

    • A.

      Muscarinic receptors.

    • B.

      α adrenergic receptors.

    • C.

      Nicotinic receptors.

    • D.

      β adrenergic receptors.

    • E.

      Glutamate receptors.

    Correct Answer
    C. Nicotinic receptors.
    Explanation
    Acetylcholine is the neurotransmitter responsible for activating nicotinic receptors in the adrenal medulla. When acetylcholine binds to nicotinic receptors, it triggers the release of epinephrine from the adrenal medulla, leading to an increase in heart rate. Therefore, the correct answer is nicotinic receptors.

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  • 25. 

    A 56-year-old woman goes to an ophthalmologist for an eye examination. The ophthalmologist administers an eye drop to dilate her pupils prior to the eye examination. The medication in the eye drop is most likely acting on

    • A.

      Serotonin receptors.

    • B.

      α1 adrenergic receptors.

    • C.

      β2 adrenergic receptors.

    • D.

      Nicotinic receptors.

    • E.

      Acetylcholinesterase.

    Correct Answer
    B. α1 adrenergic receptors.
    Explanation
    The medication in the eye drop is most likely acting on α1 adrenergic receptors. This is because α1 adrenergic receptors are responsible for pupil dilation. When these receptors are stimulated, the muscles in the iris contract, causing the pupil to dilate. Therefore, the medication in the eye drop is likely targeting these receptors to achieve pupil dilation for the eye examination.

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  • 26. 

    The neurotransmitter at the neuromuscular junction is

    • A.

      Acetylcholine.

    • B.

      Norepinephrine.

    • C.

      Serotonin.

    • D.

      Aspartate.

    • E.

      Epinephrine.

    Correct Answer
    A. Acetylcholine.
    Explanation
    Acetylcholine is the correct answer because it is the primary neurotransmitter responsible for transmitting signals from motor neurons to muscle fibers at the neuromuscular junction. It is released by the motor neuron and binds to receptors on the muscle fiber, leading to muscle contraction. Norepinephrine, serotonin, aspartate, and epinephrine are all neurotransmitters involved in other functions within the nervous system, but they are not specifically associated with the neuromuscular junction.

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  • 27. 

    A 33-year-old woman with a brain infection (meningitis) is administered her antibiotic directly into the cerebrospinal fluid because the

    • A.

      Bacteria causing the brain infection are not sensitive to the antibiotic.

    • B.

      Blood brain barrier excludes the antibiotic if it is administered systemically.

    • C.

      Antibiotic binds to brain cells and is not available to the bacteria.

    • D.

      Antibiotic is activated by the cerebrospinal fluid.

    • E.

      Bacteria are mostly located in the cerebrospinal fluid.

    Correct Answer
    B. Blood brain barrier excludes the antibiotic if it is administered systemically.
    Explanation
    The correct answer is that the blood brain barrier excludes the antibiotic if it is administered systemically. The blood brain barrier is a protective barrier that separates the circulating blood from the brain and spinal cord. It is composed of specialized cells that tightly regulate what substances can pass through into the brain. Many antibiotics are unable to cross this barrier when administered systemically, which can limit their effectiveness in treating brain infections. Therefore, administering the antibiotic directly into the cerebrospinal fluid bypasses the blood brain barrier and allows for direct delivery to the site of infection.

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  • 28. 

    An 80-year-old woman is administered a CNS depressant drug for anxiety. When she abruptly stops the drug, after taking it for many years, she is likely to experience

    • A.

      Increased sedation.

    • B.

      Hyperexcitability.

    • C.

      A depressed mood.

    • D.

      Nausea.

    • E.

      Blurred vision

    Correct Answer
    B. Hyperexcitability.
    Explanation
    When the 80-year-old woman abruptly stops taking the CNS depressant drug for anxiety, she is likely to experience hyperexcitability. This is because long-term use of CNS depressants can lead to tolerance and dependence. Abruptly stopping the drug can cause withdrawal symptoms, and in this case, hyperexcitability is a common withdrawal symptom. This means that the woman may experience increased agitation, restlessness, and heightened sensitivity to stimuli.

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  • 29. 

    A 35-year-old man has ingested Amanita muscaria mushrooms. He is experiencing a heart rate of 40 beats per minute. This bradycardia is most likely due to an interaction of the chemical(s) in the mushrooms with which receptors at the sinoatrial node?

    • A.

      α1 Adrenergic

    • B.

      β1 Adrenergic

    • C.

      β2 Adrenergic

    • D.

      M2 muscarinic

    • E.

      Nicotinic

    Correct Answer
    D. M2 muscarinic
    Explanation
    The bradycardia observed in the 35-year-old man who ingested Amanita muscaria mushrooms is most likely due to an interaction of the chemical(s) in the mushrooms with M2 muscarinic receptors at the sinoatrial node. M2 muscarinic receptors are found in the heart and their activation leads to a decrease in heart rate.

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  • 30. 

    A 49-year-old woman is treated with pilocarpine hydrochloride for xerostomia (dry mouth) following head and neck radiation treatments. As a result of taking this drug she may experience which of the following side effects?

    • A.

      Sweating

    • B.

      Dry eyes

    • C.

      Dry skin

    • D.

      Confusion

    • E.

      Tachycardia

    Correct Answer
    A. Sweating
    Explanation
    Pilocarpine hydrochloride is a medication that stimulates the sweat glands, leading to increased sweating. Therefore, it is expected that a 49-year-old woman who is being treated with this drug for xerostomia may experience sweating as a side effect.

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  • 31. 

    A 54-year-old woman is receiving Botox injections to remove facial wrinkles. Botox (botulinum toxin) acts by

    • A.

      Stimulating the release of ACh.

    • B.

      Stimulating the release of norepinephrine.

    • C.

      Blocking the release of ACh.

    • D.

      Blocking the release of norepinephrine.

    • E.

      Blocking muscarinic receptors.

    Correct Answer
    C. Blocking the release of ACh.
    Explanation
    Botox (botulinum toxin) is known to block the release of acetylcholine (ACh). Acetylcholine is a neurotransmitter that plays a role in muscle contraction. By blocking its release, Botox inhibits the communication between nerves and muscles, resulting in temporary muscle paralysis. This paralysis helps to reduce the appearance of facial wrinkles by preventing the repetitive muscle contractions that contribute to their formation.

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  • 32. 

    A 23-year-old man has deliberately ingested an organophosphate insecticide. His initial symptoms of salivation, lacrimation, and diarrhea are a consequence of inhibition of

    • A.

      Butyrylcholinesterase.

    • B.

      Acetylcholinesterase.

    • C.

      Na+, K+-A Pase.

    • D.

      Tyrosine hydroxylase.

    • E.

      Monoamine oxidase.

    Correct Answer
    B. Acetylcholinesterase.
    Explanation
    The initial symptoms of salivation, lacrimation, and diarrhea are consistent with the effects of increased acetylcholine activity. Organophosphate insecticides inhibit acetylcholinesterase, the enzyme responsible for breaking down acetylcholine. This inhibition leads to an accumulation of acetylcholine in the body, causing excessive stimulation of cholinergic receptors and resulting in symptoms such as increased salivation, tearing, and gastrointestinal disturbances. Therefore, the correct answer is acetylcholinesterase.

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  • 33. 

    The patient in Question 10 should be treated with atropine and which additional drug in the following list?

    • A.

      Physostigmine

    • B.

      Bethanechol

    • C.

       Pralidoxime

    • D.

      Morphine

    • E.

      Gentamicin

    Correct Answer
    C.  Pralidoxime
    Explanation
    Pralidoxime is the correct additional drug to be used in combination with atropine for the treatment of the patient in Question 10. Atropine is commonly used to treat symptoms of organophosphate poisoning, such as excessive salivation, sweating, bronchospasm, and bradycardia. Pralidoxime is another medication used in the treatment of organophosphate poisoning, as it helps to reactivate the enzyme acetylcholinesterase, which is inhibited by organophosphates. By combining atropine and pralidoxime, the effects of organophosphate poisoning can be effectively counteracted.

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  • 34. 

    A 65-year-old man with the diagnosis of Alzheimer’s disease is being treated with donepezil. This drug acts by

    • A.

      Stimulating the release of ACh.

    • B.

      Blocking the reuptake of norepinephrine.

    • C.

      Inhibiting monamine oxidase.

    • D.

      Blocking the release of ACh.

    • E.

      Inhibiting AChE.

    Correct Answer
    E. Inhibiting AChE.
    Explanation
    Donepezil is a medication used to treat Alzheimer's disease. It works by inhibiting acetylcholinesterase (AChE), an enzyme that breaks down acetylcholine (ACh) in the brain. By inhibiting AChE, donepezil increases the levels of ACh in the brain, which helps to improve cognitive function in individuals with Alzheimer's disease. Therefore, the correct answer is inhibiting AChE.

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  • 35. 

    A 72-year-old woman receives succinylcholine as an adjuvant muscle relaxant during knee surgery. This drug acts by

    • A.

      Blocking ACh at nicotinic receptors of neuromuscular endplate.

    • B.

      Blocking ACh at nicotinic receptors in the adrenal medulla.

    • C.

      Increasing Na+ and K+ permeability of the postsynaptic neuromuscular membrane.

    • D.

      Blocking the transmission of the action potential along the nerve axon.

    • E.

      Blocking the release of ACh from neuromuscular presynaptic vesicles.

    Correct Answer
    C. Increasing Na+ and K+ permeability of the postsynaptic neuromuscular membrane.
    Explanation
    Succinylcholine acts by increasing the permeability of Na+ and K+ ions in the postsynaptic neuromuscular membrane. This leads to depolarization of the muscle fiber and subsequent muscle relaxation. Blocking ACh at nicotinic receptors of the neuromuscular endplate, blocking ACh at nicotinic receptors in the adrenal medulla, blocking the transmission of the action potential along the nerve axon, and blocking the release of ACh from neuromuscular presynaptic vesicles are not the correct mechanisms of action for succinylcholine.

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  • 36. 

    A 3-year-old boy is brought to the emergency room because he has ingested a large amount of a nicotine-containing product. Serious nicotine toxicity in this child is the result of

    • A.

      Blockade of transmission at autonomic ganglia and neuromuscular junctions.

    • B.

      Blockade of muscarinic receptors.

    • C.

      Stimulation of adrenergic receptors.

    • D.

      Blockade of adrenergic receptors.

    • E.

      Stimulation of muscarinic receptors.

    Correct Answer
    A. Blockade of transmission at autonomic ganglia and neuromuscular junctions.
    Explanation
    Ingesting a large amount of a nicotine-containing product can lead to serious nicotine toxicity. Nicotine acts by binding to and activating nicotinic acetylcholine receptors (nAChRs) in the autonomic ganglia and neuromuscular junctions. When these receptors are activated, transmission at these sites is facilitated. However, in this case, the child is experiencing serious nicotine toxicity, which suggests that there is a blockade of transmission at these autonomic ganglia and neuromuscular junctions instead. This blockade can lead to various symptoms such as muscle weakness, respiratory distress, and cardiovascular effects.

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  • 37. 

    A 53-year-old woman with COPD is using an albuterol inhaler for symptomatic relief of bronchospasm. She does not like using her inhaler because it causes

    • A.

      Her lips to turn black.

    • B.

      Her heart to beat faster.

    • C.

      Numbness in her fingers and toes.

    • D.

      Transient blindness.

    • E.

      Transient diminished hearing

    Correct Answer
    B. Her heart to beat faster.
    Explanation
    The correct answer is "her heart to beat faster." Albuterol is a bronchodilator medication that works by relaxing the muscles in the airways, allowing for easier breathing. One of the common side effects of albuterol is an increased heart rate or palpitations. This occurs because albuterol can stimulate the beta-2 adrenergic receptors in the heart, leading to an increase in heart rate. It is important for patients with COPD to be aware of this side effect and to monitor their heart rate while using albuterol.

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  • 38. 

    A 34-year-old woman has been frequently using a nasal spray containing the α adrenergic receptor agonist oxymetazoline for nasal decongestion. She has recently noticed that it is less effective and her symptoms are worse. T is loss of efficacy is most likely due to

    • A.

      The act that her spray container is empty.

    • B.

      Degradation of the oxymetazoline.

    • C.

      A manufacturing defect in the nasal spray container.

    • D.

      A loss of innervation to her nasal mucosa.

    • E.

      Rebound hyperemia of her nasal mucosa

    Correct Answer
    E. Rebound hyperemia of her nasal mucosa
    Explanation
    The loss of efficacy of the nasal spray is most likely due to rebound hyperemia of the nasal mucosa. Rebound hyperemia occurs when the blood vessels in the nasal mucosa dilate excessively after the vasoconstrictive effects of the nasal spray wear off. This can lead to worsening symptoms and decreased effectiveness of the spray.

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  • 39. 

    A 32-year-old woman with the diagnosis of a pheochromocytoma is scheduled for surgery to remove her adrenal tumor. The best drug to control her episodes of severe hypertension prior to surgery would be

    • A.

      A nonselective α adrenergic antagonist such as phenoxybenzamine.

    • B.

      A selective α2 adrenergic receptor agonist such as clonidine.

    • C.

      A selective β2 adrenergic receptor agonist such as terbutaline.

    • D.

      A nonselective β adrenergic receptor antagonist such as propranolol.

    • E.

      A selective α1 adrenergic receptor antagonist such as terazosin.

    Correct Answer
    A. A nonselective α adrenergic antagonist such as phenoxybenzamine.
    Explanation
    The correct answer is a nonselective α adrenergic antagonist such as phenoxybenzamine. Pheochromocytoma is a tumor of the adrenal glands that secretes excessive amounts of catecholamines, leading to severe hypertension. α adrenergic antagonists block the effects of catecholamines on α receptors, reducing blood pressure. Phenoxybenzamine is a nonselective α adrenergic antagonist and is the drug of choice for preoperative management of pheochromocytoma. Selective α2 adrenergic receptor agonists, selective β2 adrenergic receptor agonists, nonselective β adrenergic receptor antagonists, and selective α1 adrenergic receptor antagonists are not recommended for this condition.

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  • 40. 

    The typical dose of oral propranolol for the treatment of hypertension is 320 mg/day. The typical dose of IV propranolol to treat a life-threatening arrhythmia is 1 to 3 mg administered slowly. The reason for the discrepancy in these doses is

    • A.

      β adrenergic receptors are more sensitive to IV than oral propranolol.

    • B.

      The IV dose avoids the “first pass” metabolism of oral propranolol.

    • C.

      Treatment of hypertension requires a higher dose of propranolol than does treatment of a cardiac arrhythmia.

    • D.

      The density of β2 receptors in the heart is greater than the density of β2 receptors on blood vessels.

    • E.

      Oral propranolol is excreted by the kidney at a faster rate than IV propranolol.

    Correct Answer
    B. The IV dose avoids the “first pass” metabolism of oral propranolol.
    Explanation
    The reason for the discrepancy in the doses of oral and IV propranolol is that the IV dose avoids the "first pass" metabolism of oral propranolol. When a drug is taken orally, it first passes through the liver before entering the systemic circulation. This process, known as first pass metabolism, can lead to the breakdown and inactivation of a significant portion of the drug. By administering propranolol intravenously, the drug bypasses the liver and enters the systemic circulation directly, resulting in a higher bioavailability and therefore a lower required dose compared to oral administration.

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  • 41. 

    A 32-year-old woman is taking sertraline for mild depression. This drug increases the availability of serotonin (5-HT) at the postsynaptic membrane because it

    • A.

      Stimulates 5-HT receptors.

    • B.

      Enhances the release of 5-HT from presynaptic nerve endings.

    • C.

      Inhibits the presynaptic uptake of 5-HT.

    • D.

      Blocks MAO which degrades 5-HT.

    • E.

      Enhances the synthesis of 5-HT.

    Correct Answer
    C. Inhibits the presynaptic uptake of 5-HT.
    Explanation
    Sertraline is a selective serotonin reuptake inhibitor (SSRI), which means it inhibits the presynaptic uptake of serotonin (5-HT). This means that sertraline prevents the reuptake of serotonin into the presynaptic neuron, allowing more serotonin to remain in the synaptic cleft and increase its availability at the postsynaptic membrane. This mechanism of action helps to alleviate symptoms of depression by increasing serotonin levels in the brain.

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  • 42. 

    Clinical studies have shown that adrenoceptor blockers have many useful effects in patients. However, a number of drug toxicities have been documented. Adverse effects that limit the use of adrenoceptor blockers include which one of the following?

    • A.

      Bronchoconstriction from α-blocking agents

    • B.

      Acute heart failure exacerbation from β blockers

    • C.

      Impaired blood sugar response with α blockers

    • D.

      Increased intraocular pressure with β blockers

    • E.

      Sleep disturbances from α-blocking drug

    Correct Answer
    B. Acute heart failure exacerbation from β blockers
    Explanation
    Clinical studies have shown that adrenoceptor blockers have many useful effects in patients. However, one of the adverse effects that limit the use of adrenoceptor blockers is acute heart failure exacerbation from β blockers. This means that β blockers can worsen heart failure symptoms in patients, making it a potential risk for those with heart failure.

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  • 43. 

    A 56-year-old man who has a 30-year history of smoking cigarettes is being treated for schizophrenia with clozapine. He is hospitalized for an acute exacerbation of his psychoses; his clozapine therapy is continued. During the third week of his hospital stay, he has a seizure that is thought to be due to clozapine toxicity. The clozapine toxicity in this patient is likely due to

    • A.

      Increased GI absorption of clozapine.

    • B.

      Decreased renal excretion of clozapine.

    • C.

      A decrease in his blood-brain barrier function.

    • D.

      Decreased metabolism of clozapine.

    • E.

      A pharmacy mistake.

    Correct Answer
    D. Decreased metabolism of clozapine.
    Explanation
    The correct answer is decreased metabolism of clozapine. Clozapine is primarily metabolized by the liver, specifically by the cytochrome P450 enzyme system. In individuals with decreased liver function, such as those with liver disease or older age, the metabolism of clozapine may be impaired. This can lead to higher levels of the drug in the body, increasing the risk of toxicity. In this case, the patient's long history of smoking cigarettes may have contributed to liver dysfunction, resulting in decreased metabolism of clozapine and subsequent toxicity.

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  • 44. 

    A 22-year-old woman is being treated with amitriptyline or depression. She, and her family, should be cautioned about not seeing a therapeutic effect for

    • A.

      24 hours.

    • B.

      12 hours.

    • C.

      3 days.

    • D.

      1 week.

    • E.

      3 to 4 weeks.

    Correct Answer
    E. 3 to 4 weeks.
    Explanation
    The therapeutic effect of amitriptyline for depression may take 3 to 4 weeks to become noticeable. It is important for the woman and her family to be aware of this timeframe to manage their expectations and avoid premature discontinuation of the medication.

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  • 45. 

    A 75-year-old man with obsessive compulsive disorder is treated with risperidone. After 3 weeks of therapy, he develops bradykinesia, masked facies, and reduced arm movements when walking. These symptoms are due to

    • A.

      α1-adrenergic receptor antagonism.

    • B.

      β-adrenergic receptor antagonism.

    • C.

      5-HT receptor stimulation.

    • D.

      D2 receptor antagonism.

    • E.

      Blockade of norepinephrine uptake into presynaptic terminals.

    Correct Answer
    D. D2 receptor antagonism.
    Explanation
    The symptoms described, including bradykinesia (slowness of movement), masked facies (reduced facial expression), and reduced arm movements when walking, are characteristic of parkinsonism. These symptoms are commonly associated with D2 receptor antagonism, which is a known side effect of risperidone, an atypical antipsychotic medication. D2 receptor antagonism can lead to a decrease in dopamine activity in the brain, resulting in the development of parkinsonian symptoms.

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  • 46. 

    A 43-year-old woman is being treated with olanzapine for schizophrenia. Although olanzapine appeared to be improving her behavioral symptoms, she stopped using the drug likely due to

    • A.

      An unusual taste.

    • B.

      Increased libido.

    • C.

      Weight gain.

    • D.

      Her urine turned green.

    • E.

      Hirsutism.

    Correct Answer
    C. Weight gain.
    Explanation
    The most likely reason for the woman to stop using olanzapine is weight gain. Olanzapine is an atypical antipsychotic medication commonly associated with significant weight gain as a side effect. This can be concerning for patients, as weight gain can lead to various health issues and impact their overall well-being. Therefore, the woman may have decided to discontinue the medication due to this side effect.

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  • 47. 

    A 36-year-old woman presents with symptoms of major depression that are unrelated to a general medical condition, bereavement, or substance abuse. She is not currently taking any prescription or over-the-counter medications. Drug treatment is to be initiated with sertraline. In your information to the patient, you would tell her that

    • A.

      Sertraline may take 2 weeks or more to become effective

    • B.

      It is preferable that she take the drug in the morning

    • C.

      Muscle cramps and twitches can occur

    • D.

      She should notify you if she anticipates using other prescription drugs

    • E.

      All of the above

    Correct Answer
    E. All of the above
    Explanation
    The explanation for the correct answer "All of the above" is that all of the statements provided are true and relevant to the patient's treatment with sertraline. Sertraline is an antidepressant medication that may take 2 weeks or more to show its full effectiveness. It is generally recommended to take the drug in the morning to minimize the risk of insomnia. Muscle cramps and twitches can be potential side effects of sertraline. It is important for the patient to notify the healthcare provider if she anticipates using other prescription drugs to avoid potential drug interactions.

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  • 48. 

    SSRIs are much less effective than tricyclic antidepressants in the management of

    • A.

       Bulimia

    • B.

      Chronic pain of neuropathic origin

    • C.

      Generalized anxiety disorder

    • D.

      Obsessive-compulsive disorder

    • E.

      Premenstrual dysphoric disorder

    Correct Answer
    B. Chronic pain of neuropathic origin
    Explanation
    Tricyclic antidepressants are more effective than SSRIs in managing chronic pain of neuropathic origin. This is because tricyclic antidepressants have a stronger analgesic effect and can help alleviate the neuropathic pain symptoms more effectively. SSRIs, on the other hand, are commonly used for the treatment of depression and anxiety disorders but have limited efficacy in managing chronic pain. Therefore, for patients with chronic pain of neuropathic origin, tricyclic antidepressants would be a more suitable treatment option.

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  • 49. 

    A 19-year-old college student has overdosed on phenobarbital. After standard supportive care, the physician in the ER should do which of the following to hasten the elimination of phenobarbital?

    • A.

      Acidify the urine

    • B.

      Acidify the blood

    • C.

      Alkalinize the blood

    • D.

      Alkalinize the urine

    • E.

      Use a drug to stimulate hepatic CYP 2C19

    Correct Answer
    D. Alkalinize the urine
    Explanation
    Alkalinizing the urine can help hasten the elimination of phenobarbital. Phenobarbital is a weak acid, and increasing the pH of the urine can promote its ionization and decrease its reabsorption in the renal tubules. This leads to increased excretion of the drug in the urine, effectively eliminating it from the body at a faster rate.

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  • 50. 

    A 32-year-old woman is taking ramelteon for chronic insomnia. Ramelteon binds to

    • A.

      Melatonin receptors M1 and M2.

    • B.

      Muscarinic receptors M3.

    • C.

      Nicotinic receptors.

    • D.

      α1-adrenergic receptors.

    • E.

      D2 dopaminergic receptors.

    Correct Answer
    A. Melatonin receptors M1 and M2.
    Explanation
    Ramelteon is a medication used to treat chronic insomnia. It works by binding to melatonin receptors M1 and M2. Melatonin is a hormone that regulates the sleep-wake cycle, and by binding to these receptors, ramelteon helps to promote sleep. This explanation aligns with the information provided in the question and accurately describes the mechanism of action of ramelteon.

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Quiz Review Timeline +

Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.

  • Current Version
  • Mar 22, 2023
    Quiz Edited by
    ProProfs Editorial Team
  • Jun 29, 2020
    Quiz Created by
    Mai Hoang
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