All are the side effects of tacrolimus EXCEPT:
**Core Concept**
Tacrolimus is a calcineurin inhibitor used as an immunosuppressive agent to prevent organ rejection in transplant patients. It works by inhibiting the activation of T-lymphocytes, which are a key component of the immune response.
**Why the Correct Answer is Right**
Tacrolimus has several side effects due to its mechanism of action and pharmacological properties. It can cause nephrotoxicity by reducing renal blood flow and impairing the function of the renal tubules. Additionally, tacrolimus can cause neurotoxicity, including tremors, seizures, and psychosis, by altering the function of the blood-brain barrier and affecting neurotransmitter levels. Furthermore, tacrolimus can cause hepatotoxicity, gastrointestinal disturbances, and diabetes mellitus as a result of its immunosuppressive effects.
**Why Each Wrong Option is Incorrect**
**Option A:** Nausea and vomiting are common side effects of tacrolimus, often occurring within the first few days of treatment. They are a result of the drug's effects on the gastrointestinal tract and can be managed with antiemetic medications.
**Option B:** Diarrhea is a potential side effect of tacrolimus, particularly in the initial stages of treatment. It is thought to be caused by the drug's effects on the intestinal microbiome and can be managed with antidiarrheal medications.
**Option C:** Hirsutism is not a known side effect of tacrolimus. In fact, tacrolimus can cause alopecia (hair loss) as a result of its immunosuppressive effects.
**Clinical Pearl / High-Yield Fact**
Tacrolimus levels should be monitored regularly to prevent toxicity and optimize immunosuppression. A trough level of 8-12 ng/mL is typically considered therapeutic, but levels above 15 ng/mL can increase the risk of nephrotoxicity and other adverse effects.
**Correct Answer: C. Hirsutism.**