In which situation is the use of sirolimus least appropriate?

Sirolimus is an immunosuppressant that is often used in transplant patients to prevent organ rejection. However, it has a side effect profile that includes the potential to cause hyperlipidemia. Therefore, in a patient with an abnormal lipid profile, the use of sirolimus is least appropriate because it can exacerbate lipid abnormalities.

In contrast, regarding the other scenarios presented:

• In primary renal failure, sirolimus can be considered if it is used in a context where the renal function is being closely monitored since its renal effects differ from those of calcineurin inhibitors.

• For a patient who has experienced neurotoxicity from calcineurin inhibitors, sirolimus offers an alternative immunosuppressive pathway that can be beneficial while avoiding the neurotoxic effects of those prior medications.

• A patient who is 6 months post-liver transplant with a healed incision is generally in a stable condition, making sirolimus a viable option to prevent rejection.

Thus, aligning sirolimus therapy with the patient’s clinical status and risk factors is crucial, especially with preexisting lipid issues that could be worsened by the drug.