Principles Of Pharmacology Quiz: Test!

When a drug is bound to blood elements or plasma proteins, it means that a certain percentage of the drug is attached to these components and is not available to exert its pharmacological effects. In this case, if the drug is 80% bound, it means that only 20% of the drug remains in its free form, which is not bound to any components and is able to act on its target receptors or exert its therapeutic effects. Therefore, the correct answer is 20%.

Propranolol (Inderal) is classified as an antihypertensive drug. It is commonly used to treat high blood pressure and prevent angina (chest pain) and heart attacks. Propranolol works by blocking the effects of adrenaline, which helps to lower blood pressure and reduce the workload on the heart. It is not an anticonvulsive, antihistamine, antinauseant, or antipyretic drug.

An agonist is a drug that binds to a receptor and stimulates cellular activity. Unlike an antagonist, which inhibits or opposes cellular activity, an agonist activates the receptor and triggers a response in the cell. This can lead to various physiological effects, such as increased neurotransmitter release or muscle contraction. Agonists are commonly used in medical treatments to mimic the effects of natural substances in the body or to enhance cellular activity for therapeutic purposes.

The word pharmacology is derived from the Greek words "pharmakon" meaning drug or medicine, and "logos" meaning study. Therefore, the etymology of the word does not include the term "HERB".

If a patient misses three doses of their daily drug, the best solution, in general, is to do nothing and continue with the normal regimen. This is because abruptly changing the dosage or waiting for a longer period before resuming the normal regimen can have adverse effects on the patient's health. It is important to maintain consistency in medication schedules, and missing a few doses does not necessarily warrant any immediate changes or evaluations.

Atropine would be considered a toxin because it is a naturally occurring compound found in plants such as deadly nightshade. It acts as a competitive antagonist of acetylcholine at muscarinic receptors, blocking the effects of the neurotransmitter. Atropine can cause various toxic effects such as dry mouth, blurred vision, increased heart rate, and even hallucinations in high doses. Therefore, it qualifies as a poison of biological origin.

Epinephrine acts directly through receptors to increase heart rate and blood pressure. Epinephrine binds to adrenergic receptors in the heart and blood vessels, activating them and causing an increase in heart rate and constriction of blood vessels, leading to an increase in blood pressure. This direct interaction with receptors is what allows epinephrine to have its desired physiological effects on the cardiovascular system.

Chloramphenicol is risky for neonates because it can cause a serious condition called gray baby syndrome, where the baby's skin turns gray and they experience difficulty in breathing, low body temperature, low blood pressure, and even death. Neonates have immature liver function, which leads to the accumulation of chloramphenicol in their body, causing toxicity. Therefore, it is important to avoid using chloramphenicol in neonates and choose alternative antibiotics instead.

Xenobiotics are considered exogenous because they are substances that are foreign to the body and are not naturally produced or found within it. They can include drugs, chemicals, pollutants, and other substances that are introduced into the body from external sources. These exogenous substances can have various effects on the body, including toxicity and the potential to cause harm. Therefore, xenobiotics are categorized as exogenous rather than endogenous, which refers to substances that are naturally produced within the body.

The side of action (transport) is not a protein target for drug binding. Drug targets are typically proteins that are involved in specific biological processes or pathways, such as enzymes, carrier molecules, receptors, and ion channels. These proteins play crucial roles in mediating the effects of drugs on cells and tissues. However, the side of action (transport) refers to the location or site where a drug exerts its effects, such as the site of action for drug absorption, distribution, metabolism, or excretion. It is not a specific protein target for drug binding.

In the lock and key model, drugs fit receptors through covalent bonds. Covalent bonds are the strongest type of chemical bond, meaning they require a significant amount of energy to break. Therefore, when drugs form covalent bonds with receptors, it creates a strong and stable interaction. On the other hand, the term "least specific" refers to the fact that covalent bonds are not highly selective in terms of the specific receptors they interact with. They are more likely to form bonds with a variety of different receptors, making them less specific compared to other types of bonds.

The glomerular filtration rate (GFR) is the rate at which blood is filtered by the kidneys. As a person ages, the GFR tends to decrease gradually. This is because the kidneys become less efficient in filtering waste products from the blood. The decrease in GFR is estimated to be around 1% per year after the age of 40. This decline in kidney function is a normal part of the aging process and can lead to a decreased ability to remove waste products from the body.

The minimal effective concentration (MEC) refers to the minimum drug plasma concentration required to produce a therapeutic effect. This means that the drug needs to reach a certain concentration in the bloodstream in order to have the desired effect on the body. It is important to reach this minimal concentration to ensure that the drug is effective and produces the desired outcome.

As renal and liver function decreases in the elderly, the ability to eliminate drugs from the body is impaired. This leads to a longer drug half-life, meaning it takes longer for the drug to be cleared from the body. Additionally, a decrease in renal and liver function can also result in a decrease in plasma protein binding, which is the process by which drugs bind to proteins in the blood. When the binding decreases, more of the drug remains free and active in the bloodstream, further prolonging its effects. Finally, a decrease in renal and liver function can also lead to a decrease in the volume of distribution, which refers to the distribution of the drug throughout the body. With a smaller volume of distribution, the drug is more concentrated in the bloodstream, increasing its potency and prolonging its effects.

The correct answer is 4 * R + 1 * S = 2.5. This equation represents the potency of the mixture of Warfarin given, which is 50% S and 50% R. Since the S enantiomer is four times more active than the R enantiomer, it is given a potency of 4, while the R enantiomer is given a potency of 1. By multiplying the potency of each enantiomer by their respective percentages and summing them up, we get the total potency of the mixture. In this case, it is 4 * R + 1 * S = 2.5.