Pharm Practice Exam 2

Tetracycline is known to cause gray-brown tooth discoloration. This is because tetracycline can bind to calcium ions in developing teeth, leading to the formation of insoluble complexes that deposit in the teeth. This discoloration occurs during tooth development and is most commonly seen in children who were exposed to tetracycline during pregnancy or in early childhood. The other drugs listed (minocycline, doxycycline, and azithromycin) do not typically cause tooth discoloration.

Aztreonam belongs to the class of antibiotics known as monobactams. Monobactams are a group of antibiotics that have a unique structure consisting of a single beta-lactam ring. They are effective against certain types of bacteria, particularly Gram-negative bacteria. Aztreonam specifically targets and inhibits the growth of these Gram-negative bacteria by interfering with their cell wall synthesis. Unlike other beta-lactam antibiotics, monobactams do not have activity against Gram-positive bacteria or anaerobes.

Red Man's Syndrome is a side effect of nafcillin, characterized by flushing, itching, and rash on the upper body. Ototoxicity refers to damage to the inner ear resulting in hearing loss or balance problems. Both of these side effects can be severe and may necessitate a change to an alternative medication like trimethoprim-sulfamethoxazole.

Piperacillin could be used in the case of pneumonia caused by pseudomonas because it is a broad-spectrum antibiotic that is effective against a wide range of bacteria, including pseudomonas. It belongs to the class of antibiotics called penicillins, which work by inhibiting the growth of bacteria. Piperacillin is specifically effective against gram-negative bacteria like pseudomonas, making it a suitable choice for treating pneumonia caused by this pathogen.

Fluoroquinolones work by inhibiting the DNA gyrase of bacteria. DNA gyrase is an enzyme that is essential for bacterial DNA replication and transcription. By inhibiting this enzyme, fluoroquinolones prevent bacteria from replicating and synthesizing proteins, ultimately leading to their death. Sulfa drugs, aminoglycosides, and cephalosporins have different mechanisms of action and do not specifically target DNA gyrase.

Streptococcus pneumoniae is the most common bacterial cause of otitis media. This bacterium is responsible for causing inflammation and infection in the middle ear, leading to symptoms such as ear pain, fever, and hearing loss. It is particularly common in young children and can be spread through respiratory droplets. Prompt diagnosis and treatment with antibiotics are important to prevent complications and further spread of the infection.

Bacteroides is a gram-negative anaerobe. Gram-negative bacteria have a thin peptidoglycan layer in their cell wall, which makes them stain pink during the Gram staining process. Anaerobes are organisms that can survive and grow without oxygen. Bacteroides is a common anaerobic bacteria found in the human gut and is known to cause infections in various parts of the body, including the abdomen, skin, and respiratory tract. Peptostreptococcus, Moraxella, and Staph aureus are not gram-negative anaerobes, as they either have a different gram stain result or are not anaerobic.

Vancomycin does not belong to the broad class of protein-synthesis active drugs. Gentamicin, erythromycin, and clindamycin are all antibiotics that inhibit protein synthesis in bacteria. However, vancomycin works by interfering with cell wall synthesis in bacteria, making it a different mechanism of action compared to the other drugs listed.

Glycopeptides are a class of antibiotics that inhibit bacterial cell wall synthesis. Vancomycin is a glycopeptide antibiotic that is commonly used to treat infections caused by methicillin-resistant Staphylococcus aureus (MRSA) and other gram-positive bacteria. It works by binding to the bacterial cell wall and preventing the formation of peptidoglycan, which is essential for bacterial cell wall integrity. Vancomycin is not effective against gram-negative bacteria due to its inability to penetrate their outer membrane. Therefore, the correct match is glycopeptides - vancomycin.

Erythromycin is a concern for interactions due to its CYP450 metabolism. CYP450 enzymes are responsible for metabolizing many drugs in the body. Erythromycin is a potent inhibitor of CYP450 enzymes, particularly CYP3A4, which can lead to increased levels of other drugs that are metabolized by the same enzyme. This can result in drug interactions and potentially increase the risk of adverse effects or decrease the effectiveness of other medications. Therefore, caution should be exercised when erythromycin is used concomitantly with other drugs metabolized by CYP450 enzymes.

Crystalluria refers to the formation of crystals in the urine. Sulfas, also known as sulfonamides, are a group of antibiotics that have been associated with the development of crystalluria. These medications can precipitate and form crystals in the urine, which can lead to discomfort and potentially blockage of the urinary tract. Therefore, sulfas are a concern when it comes to the formation of crystalluria.

Given the patient's history of community-acquired pneumonia and COPD, the most appropriate treatment would be a combination of a macrolide (such as azithromycin or clarithromycin) and a beta-lactam antibiotic (such as amoxicillin or cefuroxime). This combination provides broad coverage against common pathogens that cause pneumonia, including atypical bacteria and Streptococcus pneumoniae. The patient's previous use of doxycycline for an exacerbation of chronic bronchitis suggests that they may have already been treated for atypical bacteria, making the macrolide plus beta-lactam combination more suitable. Ceftriaxone plus levofloxacin is a possible alternative, but it may be reserved for more severe cases or specific circumstances. Piperacillin is not typically used for community-acquired pneumonia.

Ethambutol is the correct answer because it is known to have optic neuritis as a side effect. Optic neuritis is an inflammation of the optic nerve, which can cause vision problems. This side effect is more commonly associated with ethambutol compared to the other TB drugs listed, such as rifamycins, pyrazinamide, and isoniazid.

Prescribing cefaclor is an appropriate reaction to the situation because it is an alternative antibiotic that is not related to penicillin. Since the patient has a penicillin allergy, it is important to avoid prescribing any medication in the penicillin class. Cefaclor belongs to a different class of antibiotics called cephalosporins, which are generally considered safe for patients with penicillin allergies. Therefore, prescribing cefaclor would provide an effective treatment option without risking an allergic reaction in the patient.

Thienamycins do not work by affecting protein synthesis. Tetracyclines, lincosamides, and macrolides are all antibiotics that inhibit bacterial protein synthesis. Thienamycins, on the other hand, are a class of beta-lactam antibiotics that work by inhibiting cell wall synthesis in bacteria. They bind to and inhibit the enzyme responsible for building the bacterial cell wall, leading to cell death. Therefore, thienamycins do not directly affect protein synthesis.

Aminoglycosides are known to be very active against gram negative aerobic organisms, including pseudomonas. These antibiotics work by inhibiting protein synthesis in bacteria, leading to their death. They are particularly effective against gram negative bacteria due to their ability to penetrate the outer membrane of these organisms. Aminoglycosides are often used in combination with other antibiotics to treat severe infections caused by gram negative bacteria.

Ampicillin is incorrectly matched to its subclass as carboxypenicillin. Ampicillin actually belongs to the subclass of aminopenicillins. Carboxypenicillins include drugs like carbenicillin and ticarcillin. Ampicillin is a broad-spectrum antibiotic that is effective against a wide range of bacteria. It is commonly used to treat various infections such as urinary tract infections, respiratory tract infections, and gastrointestinal infections.

Azetreonam is a good substitute for aminoglycosides in patients at risk for nephrotoxicity because it does not have any activity against gram-positive species. This means that it specifically targets gram-negative bacteria, which are often the cause of serious infections in these patients. By avoiding the use of aminoglycosides, which can cause kidney damage, azetreonam provides an effective alternative treatment option.

Tetracyclines do not work by binding to the 50S ribosomal subunit, which inhibits early and late bacterial protein synthesis. Tetracyclines instead bind to the 30S ribosomal subunit, preventing the attachment of aminoacyl-tRNA molecules to the ribosome, thus inhibiting protein synthesis. Streptogramins, oxalinedions, and lincosamides all work by binding to the 50S ribosomal subunit, interfering with protein synthesis in bacteria.

In an uncomplicated case of acute bacterial sinusitis, a high dose of clindamycin is not indicated in patients with penicillin allergy. Clindamycin is an alternative antibiotic that can be used in patients with penicillin allergy, but it does not necessarily require a high dose. The dosage of clindamycin should be adjusted based on the severity of the infection and the patient's individual factors.

Cefepime belongs to the fourth generation of cephalosporins. This generation of cephalosporins has an expanded spectrum of activity compared to earlier generations and is effective against a wide range of bacteria, including many Gram-positive and Gram-negative organisms. Cefepime is commonly used to treat severe infections, such as pneumonia and complicated urinary tract infections, caused by multidrug-resistant bacteria.

Otitis media with effusion should not be treated with an antibiotic because it is a condition characterized by the presence of fluid in the middle ear, usually without any signs of infection. Antibiotics are only effective in treating bacterial infections, and since otitis media with effusion is typically not caused by bacteria, antibiotics would not be beneficial in this case. Treatment for otitis media with effusion usually involves monitoring the condition and waiting for the fluid to resolve on its own.

Azithromycin is the correct answer because it is a macrolide antibiotic that is effective against the bacteria that commonly cause pharyngitis. It is often used as an alternative treatment for patients with a penicillin allergy because it does not belong to the same drug class and therefore does not cross-react with penicillin. Aztronam is not effective against the bacteria that cause pharyngitis. Clindamycin and trimethoprim-sulfamethoxazole are alternative options for patients with a penicillin allergy, but they are not the best choice for treating bacterial pharyngitis.

Norfloxacin is the correct answer because it is a fluoroquinolone antibiotic that is primarily used for the treatment of urinary tract infections (UTIs). Unlike other antibiotics in the list, norfloxacin is not a systemic agent, meaning it does not enter the bloodstream and have widespread effects throughout the body. Instead, it remains localized in the urinary tract, making it an effective choice for UTIs specifically. Moxifloxacin, ciprofloxacin, and sparfloxacin, on the other hand, are systemic agents that can be used to treat a variety of infections beyond just UTIs.

The correct answer is "inhibit cross-linking enzymes during cell wall formation." Thienamycins are a class of antibiotics that work by inhibiting the enzymes responsible for cross-linking the peptidoglycan chains in the bacterial cell wall. By preventing this cross-linking, the antibiotics weaken the cell wall, making it more susceptible to damage and ultimately leading to bacterial cell death. This mode of action is specific to thienamycins and distinguishes them from other classes of antibiotics.

According to IDSA/ATS guidelines, clarithromycin would be the most suitable treatment in previously healthy patients with community-acquired pneumonia who have had no antibiotic therapy within the last three months.

An acute exacerbation of chronic bronchitis should be treated with amoxicillin/clavulanate. This is because acute exacerbations of chronic bronchitis are often caused by bacterial infections, and amoxicillin/clavulanate is a broad-spectrum antibiotic that can effectively treat such infections. It helps to kill the bacteria causing the exacerbation and reduce inflammation in the airways, helping to alleviate symptoms and promote healing.

Levofloxacin would be an appropriate treatment for a patient with acute bacterial sinusitis caused by penicillin-resistant S. pneumoniae. Levofloxacin is a fluoroquinolone antibiotic that is effective against many bacteria, including those that are resistant to penicillin. It works by inhibiting the enzyme DNA gyrase, which is essential for bacterial DNA replication and repair. By targeting this enzyme, levofloxacin can effectively kill the bacteria causing the infection. Therefore, levofloxacin would be a suitable choice for treating the patient's condition.

If the tuberculosis treatment regimen is not effective in treating the infection, it is not recommended to add a single agent to the regimen. This suggests that combination therapy is preferred in tuberculosis treatment, as adding a single agent may not be sufficient to effectively treat the infection.

Meropenem is a good alternative treatment for the child with enterobacter aspiration pneumonia who is also experiencing Stevens-Johnson Syndrome. Stevens-Johnson Syndrome is a severe and potentially life-threatening condition that causes the epidermis to separate from the dermis. Meropenem is a broad-spectrum antibiotic that is effective against many types of bacteria, including Enterobacter species. It is often used in severe infections and can be a suitable choice for treating the child's condition.

A nitroimidazole would be used to treat the organism in question 2. Nitroimidazoles are a class of antimicrobial drugs that are effective against certain types of bacteria and parasites. They work by interfering with the DNA synthesis of the organism, leading to cell death. This type of medication is commonly used to treat infections caused by anaerobic bacteria and certain types of protozoa.

Daptomycin works by binding to bacterial cell membranes, causing rapid depolarization of the membrane potential, leading to bacterial cell death. This mechanism of action disrupts the integrity of the bacterial cell membrane, ultimately killing the bacteria.

The patient is an HIV+ individual who acquired pneumonia after being admitted to the hospital. Given that the patient finished antibiotics for strep throat two weeks ago and that many people in the hospital have had MRSA infections recently, it is likely that the patient has developed a hospital-acquired pneumonia (HAP) caused by MRSA. Therefore, the appropriate course of treatment would be ciprofloxacin (to cover for other potential pathogens), lenezolid (effective against MRSA), and carbapenem (broad-spectrum antibiotic). This combination of antibiotics would effectively target the likely pathogens causing the pneumonia in this specific patient population.

Clindamycin would be a reasonable treatment in a patient with aspiration pneumonia and a penicillin allergy because it is an alternative antibiotic that is effective against the bacteria commonly associated with aspiration pneumonia. Clindamycin belongs to the lincosamide class of antibiotics and it has a different chemical structure than penicillin, making it less likely to cause an allergic reaction in patients with penicillin allergy. Therefore, clindamycin can be a suitable choice for treating aspiration pneumonia in patients with a penicillin allergy.

Linezolid does not require a dose adjustment for renal or hepatic insufficiency. This is because linezolid is primarily metabolized in the liver and excreted through the kidneys. However, it does not accumulate significantly in patients with renal or hepatic impairment, therefore dose adjustments are not necessary.

Zanamavir should not be used in a patient with asthma or COPD because it is an inhaled medication that can cause bronchospasm and worsen respiratory symptoms in individuals with these conditions. This drug is a neuraminidase inhibitor, commonly used to treat and prevent influenza, but its inhalation route of administration makes it unsuitable for patients with asthma or COPD due to the potential for respiratory complications.

Aztronam would be a bad choice in fighting an infection caused by gram negative anaerobes because it is not effective against anaerobic bacteria. Aztronam is primarily active against aerobic gram-negative bacteria and has limited activity against gram-positive and anaerobic bacteria. Therefore, it would not be an appropriate choice for treating an infection caused by gram negative anaerobes.

The correct answer is dextromethorphan. Dextromethorphan is a medication commonly used to relieve cough symptoms associated with acute bronchitis. It works by suppressing the cough reflex in the brain. Beta 2 antagonists are primarily used for the treatment of asthma and not specifically for acute bronchitis. Rimantadine is an antiviral medication used to treat influenza A, and 2nd generation cephalosporins are antibiotics used to treat bacterial infections. Therefore, dextromethorphan is the most appropriate treatment option for acute bronchitis.

Rimantadine would be the best treatment for influenza A in an elderly patient who is a fall risk. Rimantadine is an antiviral medication that is effective against influenza A virus and has a lower risk of causing central nervous system side effects compared to amantadine. This is particularly important in elderly patients who are already at a higher risk of falls and other adverse effects. Oseltamivir and peramivir are also antiviral medications used to treat influenza, but rimantadine is a better choice in this specific scenario.

Amikacin would not be an appropriate treatment for bacterial meningitis because it is an aminoglycoside antibiotic that is primarily used to treat infections caused by aerobic Gram-negative bacteria. Bacterial meningitis is most commonly caused by Gram-positive bacteria such as Streptococcus pneumoniae or Neisseria meningitidis. Therefore, amikacin would not be effective in treating the infection.