Psoriasis treated with ciclosporin — SCE Dermatology MCQ

Correct answer: C — Reduce or stop ciclosporin and reassess renal function

The correct answer is C, reduce or stop ciclosporin and reassess renal function. Ciclosporin is nephrotoxic and hypertensive by mechanism (afferent arteriolar vasoconstriction reducing renal blood flow), and UK shared care guidance for ciclosporin in psoriasis specifies that a creatinine rise of more than 30% above baseline, confirmed on repeat testing, mandates dose reduction (typically by 25 to 50%) with renal function rechecked within 2 weeks; if the rise persists the drug should be stopped. This patient's 34% rise plus new hypertension on repeated readings meets that threshold, so action is required regardless of clinical response or drug level. A therapeutic trough level only confirms adequate drug exposure, it does not exclude dose-related nephrotoxicity or hypertension, both of which are recognised even within target range. Why the other options are wrong: B. Increase ciclosporin because the level is therapeutic: a therapeutic level does not override biochemical evidence of nephrotoxicity; increasing the dose would worsen renal impairment and blood pressure. D. Add methotrexate without renal reassessment: combining ciclosporin with methotrexate increases toxicity risk and does nothing to address the underlying nephrotoxic and hypertensive process, which must be reassessed and managed first. E. Ignore the creatinine rise because psoriasis improved: skin response is irrelevant to renal safety; unmonitored nephrotoxicity can progress to irreversible renal impairment. A. Treat with topical steroid and continue the same dose: topical steroids do not treat systemic drug-induced hypertension or nephrotoxicity and continuing the same dose perpetuates the harm. Key point: a confirmed creatinine rise greater than 30% above baseline on ciclosporin requires dose reduction or discontinuation with renal reassessment, irrespective of a therapeutic trough level or skin response.

Reference: NHS Shared Care Agreement for oral ciclosporin in psoriasis (Shropshire, based on BAD/BNF guidance): dose reduction required if serum creatinine consistently >30% above baseline, https://www.sath.nhs.uk/wp-content/uploads/2016/12/Ciclosporin-Shropshire.pdf