A 45-year-old woman has just received a kidney transplant. She is placed on several immunosuppressants to prophylactically prevent her body rejecting the donor organ. Which of the following immunosuppressants interferes with T-cell activation by modifying the activity of calcineurin?

Correct Answer: A

Rationale: Post-kidney transplant, immunosuppression prevents rejection by targeting T-cell activation. Cyclosporine binds calcineurin, inhibiting its phosphatase activity, which blocks IL-2 transcription, crucial for T-cell proliferation-making it the correct answer. Methotrexate inhibits purine synthesis, affecting rapidly dividing cells, not calcineurin. Prednisolone , a corticosteroid, suppresses inflammation broadly but doesn't target calcineurin. Sirolimus inhibits mTOR, a different pathway, affecting T-cell proliferation downstream, not calcineurin. Temsirolimus (E) is similar to sirolimus. Cyclosporine's specificity to calcineurin aligns with the question's focus, a cornerstone in transplant regimens. Its mechanism disrupts early T-cell signaling, critical for alloimmune responses, unlike the broader or alternative actions of other options. This precision ensures effective prophylaxis while distinguishing it from other immunosuppressants in the list.

Correct Answer: D

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: B

Rationale: Levodopa treats Parkinson's by crossing the blood-brain barrier and converting to dopamine, but peripheral metabolism by dopa decarboxylase reduces its availability and causes side effects like nausea. Carbidopa, a peripheral dopa decarboxylase inhibitor, doesn't cross into the CNS, so it prevents levodopa breakdown outside the brain, increasing its CNS entry and efficacy. It doesn't stimulate dopamine receptors—levodopa's metabolite does that. Absorption isn't directly enhanced; bioavailability improves due to less peripheral loss. Peripheral dopamine production decreases with carbidopa, not increases, reducing side effects. COMT inhibition (e.g., entacapone) is a separate strategy. By blocking peripheral conversion, carbidopa ensures more levodopa reaches the brain, optimizing therapy and minimizing adverse effects.

Correct Answer: D

Rationale: Nystatin is used to treat oral thrush in infants, a fungal infection often linked to Candida albicans, which can be transmitted between mother and child during breastfeeding. The key instruction for the caregiver is that the breastfeeding mother may also need treatment to prevent reinfection, as Candida can persist on the mother's nipples. This addresses the infection's source comprehensively. Giving medication before feeding may reduce efficacy as milk washes it away too quickly. Water beforehand isn't necessary and could dilute the dose. Using a cotton swab is a technique but not the priority instruction compared to preventing recurrence. Since the correct answer includes multiple options (3, 5), and choice D aligns with the critical need to treat the mother, it's the focus here for its systemic impact on treatment success.

Correct Answer: C

Rationale: Nystatin, an antifungal for candidiasis, is Category C, indicating potential fetal risks aren't fully ruled out. Assessing whether the client could be pregnant is critical to evaluate safety, as pregnancy might necessitate alternative treatments or physician consultation to avoid harm. Diet type or fat content minimally affects nystatin's topical or oral efficacy, unrelated to its safety profile. Height and weight influence dosing for some drugs, but nystatin's standard dosing isn't weight-based for most indications. Pregnancy status directly impacts risk-benefit decisions, especially for a reproductive-age female, aligning with pharmacological precautions. The nurse's review of this data ensures no teratogenic effects are risked unknowingly, making C the most critical assessment prior to administration.