In a critically ill patient with sepsis, the only effective antibiotic has a TI of 2 and known nephrotoxicity. Evaluate whether its use is justified and state what steps should be taken immediately to manage risk.

Use is justified if no safer effective alternatives exist because treating the life‑threatening infection takes precedence; immediately obtain baseline renal testing, initiate therapeutic drug monitoring where possible, and plan for dose adjustment or renal support if toxicity emerges.

Use is justified only if the patient is young and otherwise healthy; otherwise, always choose a less effective antibiotic to avoid nephrotoxicity regardless of infection severity.

Use is justified but monitoring is unnecessary because organ dysfunction in critically ill patients masks any additional drug-induced nephrotoxicity, so no action can mitigate risk.

Use is never justified because a TI of 2 indicates unacceptable risk; withhold antibiotic and provide supportive care only until the infection resolves spontaneously.