## **Core Concept**
Cephalosporins are a class of β-lactam antibiotics that are widely used to treat bacterial infections. They are primarily excreted by the kidneys, and their pharmacokinetics can be affected by renal impairment. Dose adjustments are often necessary in patients with decreased glomerular filtration rate (GFR) to prevent accumulation and potential toxicity.

## **Why the Correct Answer is Right**
Ceftriaxone is unique among cephalosporins because it is primarily excreted through the biliary system into the feces, with only a small fraction excreted unchanged in the urine. This pharmacokinetic property makes ceftriaxone less dependent on renal excretion, and therefore, dose adjustments are not required even in the presence of decreased GFR.

## **Why Each Wrong Option is Incorrect**
* **Option A:** Cefotaxime is primarily excreted by the kidneys, and its metabolites are also excreted through the urine. Dose adjustments are recommended in patients with renal impairment.
* **Option B:** Cefepime is mainly excreted unchanged in the urine, and dose adjustments are necessary in patients with decreased GFR to prevent accumulation and potential neurotoxicity.
* **Option D:** Ceftazidime is primarily excreted by the kidneys, and dose adjustments are recommended in patients with renal impairment to prevent accumulation.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that ceftriaxone is the cephalosporin that does not require dose adjustment in patients with renal impairment, making it a preferred option in patients with decreased GFR.

## **Correct Answer:** . Ceftriaxone