Which adverse effect can result if tetracycline is administered to children younger than 8 years of age?

Choice A reason: Metronidazole is effective against anaerobic bacteria and protozoa, not gram-positive organisms like MRSA. It targets microbial DNA but lacks activity against Staphylococcus aureus, making it inappropriate for treating MRSA infections, which require antibiotics with specific gram-positive coverage.

Choice B reason: Vancomycin is a first-line treatment for MRSA infections. It inhibits cell wall synthesis by binding to peptidoglycan precursors, effective against gram-positive bacteria like MRSA. Its efficacy in multidrug-resistant infections makes it the preferred choice for serious infections like pressure ulcers in hospitalized patients.

Choice C reason: Tobramycin, an aminoglycoside, targets gram-negative bacteria and is not effective against MRSA, a gram-positive organism. Its spectrum includes Pseudomonas but not resistant Staphylococcus, making it unsuitable for treating MRSA pressure ulcers, which require vancomycin or similar agents.

Choice D reason: Ciprofloxacin, a fluoroquinolone, has some activity against gram-positive bacteria but is not a first-line choice for MRSA due to variable resistance. Vancomycin is more reliable for multidrug-resistant Staphylococcus aureus, especially in serious infections like pressure ulcers, making this an incorrect choice.

Choice A reason: Blurred vision and headaches are not common side effects of niacin. Niacin lowers lipids by inhibiting hepatic VLDL production but primarily causes cutaneous effects like flushing due to prostaglandin release. Neurological symptoms are more associated with other drugs, not niacin’s lipid-lowering mechanism.

Choice B reason: Myalgia and fatigue are not typical niacin side effects. These are more associated with statins, which affect muscle tissue. Niacin’s primary adverse effects involve skin (flushing, pruritus) and gastrointestinal upset, driven by its vasodilatory and metabolic effects, not musculoskeletal symptoms.

Choice C reason: Tinnitus and urine with a burnt odor are not recognized niacin side effects. Niacin causes prostaglandin-mediated flushing and potential hepatotoxicity but does not affect auditory function or urine odor. These symptoms are unrelated to niacin’s mechanism of reducing lipid synthesis.

Choice D reason: Pruritus and cutaneous flushing are common niacin side effects. Niacin triggers prostaglandin release, causing vasodilation, leading to flushing and itching. These effects are dose-dependent and often transient, manageable with aspirin pretreatment or gradual dose escalation, making this the correct adverse effect to monitor.