A 24-year-old woman comes to the emergency department presenting with flank pain and high fever. The pain and fever have been associated with dysuria and increased frequency of urination. She is diagnosed with pyelonephritis and placed on IV antibiotics. After a couple of days, she develops ringing in her ears and feels unbalanced on her feet. What antibiotic was she most likely given?

Correct Answer: C

Rationale: In this scenario, the correct answer is C) Gentamicin. Gentamicin is an aminoglycoside antibiotic commonly used to treat severe bacterial infections like pyelonephritis. The symptoms of ringing in the ears and feeling unbalanced on the feet are indicative of ototoxicity and vestibular toxicity, known side effects of aminoglycoside antibiotics like gentamicin. Option A) Ceftriaxone is a cephalosporin antibiotic and is not associated with ototoxicity or vestibular toxicity. Option B) Ciprofloxacin is a fluoroquinolone antibiotic that does not typically cause these specific side effects. Option D) Trimethoprim-sulfamethoxazole is a combination antibiotic that also does not commonly lead to ototoxicity or vestibular toxicity. In an educational context, understanding the side effects of different antibiotics is crucial for healthcare providers to make informed decisions regarding treatment options. Knowing the potential adverse effects of medications helps in monitoring patients for any signs of toxicity and ensuring their safety and well-being throughout the course of treatment.

Correct Answer: A

Rationale: The correct answer is A) Inhibit bacterial DNA gyrase enzyme. Penicillins are a class of antibiotics that work by inhibiting cell wall synthesis in bacteria. They do this by binding to specific penicillin binding proteins (PBPs) which are involved in cell wall synthesis. This binding prevents the cross-linking of peptidoglycan layers in the bacterial cell wall, leading to cell lysis and death. Option B is incorrect because it accurately describes one of the mechanisms of action of penicillins. Option C is incorrect because it also accurately describes how penicillins work. Option D is incorrect because penicillins do not activate autolysin enzymes; rather, they prevent the normal functioning of these enzymes by disrupting cell wall synthesis. Understanding the mechanism of action of antibiotics like penicillins is crucial in the treatment of bacterial infections. By inhibiting cell wall synthesis, penicillins target a fundamental process in bacterial growth and replication, making them effective in treating a wide range of bacterial infections. Knowing the specific target of penicillins can also help in understanding bacterial resistance mechanisms and developing new antibiotics to combat resistant strains.

Correct Answer: A

Rationale: In the context of ABVD chemotherapy drugs, the correct answer to the question "Sulphonamides are inactivated by:" is A) Acetylation. Sulphonamides are a class of antibiotics commonly used in chemotherapy regimens. Acetylation is a process in which an acetyl group is added to a compound, often rendering it inactive or less effective. In the case of sulphonamides, acetylation can occur through enzymatic processes in the liver, leading to the inactivation of these drugs. Regarding why the other options are incorrect: - B) Methylation: Methylation involves the addition of a methyl group, not an acetyl group, and is not the primary mechanism of inactivation for sulphonamides. - C) Deamination: Deamination is the removal of an amino group, which is not the primary mechanism for inactivating sulphonamides. - D) Oxidation: While oxidation can be a metabolic pathway for drug inactivation, acetylation is the primary mechanism for inactivating sulphonamides specifically. Educational context: Understanding how drugs are metabolized and inactivated in the body is crucial in pharmacology and chemotherapy. Knowledge of these processes helps healthcare professionals determine dosages, potential drug interactions, and the effectiveness of treatment regimens. In the case of sulphonamides used in ABVD chemotherapy, knowing that acetylation is the primary inactivation pathway can guide clinical decision-making and patient care.

Correct Answer: B

Rationale: Sulphonamides are a class of antibiotics commonly used to treat bacterial infections. The correct answer, B) Amebic dysentery, is right because sulphonamides are not effective against parasitic infections like amebic dysentery. Option A) Urinary tract infection is incorrect because sulphonamides are commonly used to treat UTIs due to their effectiveness against certain bacteria commonly causing these infections. Option C) Meningococcal meningitis is incorrect because sulphonamides can be used in the treatment of meningococcal meningitis as they are effective against the bacteria Neisseria meningitidis, which causes this condition. Option D) Respiratory infection is incorrect because sulphonamides are also effective against some of the bacteria that commonly cause respiratory infections, such as Streptococcus pneumoniae. In an educational context, understanding the specific uses and limitations of different classes of antibiotics, like sulphonamides, is crucial for healthcare professionals to make informed decisions when treating various infections. This knowledge helps in selecting the most appropriate antibiotic therapy based on the type of infection and the causative organism, thus improving patient outcomes and preventing the development of antibiotic resistance.

Correct Answer: D

Rationale: The correct answer is D) Sulphonamides. Sulphonamides are a class of antibiotic drugs known to produce crystalluria as a side effect. Crystalluria is the formation of crystals in the urine, which can lead to kidney damage or blockage of the urinary tract. Option A) Cephalosporins are not typically associated with crystalluria as a side effect. They are more commonly known for causing allergic reactions or gastrointestinal disturbances. Option B) Chloramphenicol is not linked to crystalluria. It is associated with side effects like bone marrow suppression and aplastic anemia. Option C) Tetracycline antibiotics are known to cause discoloration of teeth in children and liver toxicity but not crystalluria. Educationally, understanding the side effects of different classes of antibiotics is crucial for healthcare professionals in prescribing medications and monitoring for potential adverse reactions in patients. Recognizing the specific side effects of sulphonamides, such as crystalluria, can help in early detection and management to prevent serious complications.