Which of the following antimicrobials needs dose reduction even in mild renal failure ?
**Core Concept**
The question is testing the student's knowledge of drug pharmacokinetics in the context of renal impairment. Specifically, it's evaluating their understanding of how different antimicrobials are affected by decreased renal function.
**Why the Correct Answer is Right**
Certain antimicrobials, such as aminoglycosides, require dose adjustment even in mild renal failure because they are primarily excreted unchanged by the kidneys. If not adjusted, accumulation can occur, leading to increased toxicity. Aminoglycosides inhibit protein synthesis by binding to the 30S ribosomal subunit, thereby preventing bacterial growth. In patients with renal impairment, the elimination half-life of aminoglycosides is prolonged, necessitating dose reduction to prevent nephrotoxicity and ototoxicity.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because cephalosporins, such as ceftriaxone, are primarily excreted by the liver and do not require dose adjustment in mild renal failure.
* **Option B:** This option is incorrect because fluoroquinolones, such as ciprofloxacin, are primarily excreted by the kidneys but typically do not require dose adjustment in mild renal failure.
* **Option D:** This option is incorrect because metronidazole is primarily metabolized by the liver and does not require dose adjustment in renal failure.
**Clinical Pearl / High-Yield Fact**
Aminoglycosides are a classic example of drugs that require dose adjustment in renal failure, highlighting the importance of careful monitoring of renal function in patients receiving these medications.
**Correct Answer:** C. Aminoglycosides.