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Systemic lupus erythematosus treated with mycophenolate mofetil — DFSRH MCQ

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EasyRheumatologySystemic lupus erythematosus treated with mycophenolate mofetilDFSRH

A 32-year-old woman with systemic lupus erythematosus and previous class IV lupus nephritis wishes to conceive. Her disease has been clinically quiescent for 18 months. She takes mycophenolate mofetil 1 g twice daily and hydroxychloroquine and has an etonogestrel implant within its licensed duration. Following preconception review, her rheumatologist plans to stop mycophenolate today and use a pregnancy-compatible immunosuppressive regimen. She has had no unprotected sexual intercourse and asks when her implant can be removed. Which is the most appropriate contraceptive plan?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: E — Continue the implant for 6 weeks after the last mycophenolate dose, then remove it

Explanation lettering: E = shown as A · C = shown as B · A = shown as C · B = shown as D · D = shown as E

Mycophenolate is a potent human teratogen associated with substantial risks of miscarriage and congenital malformation. UK product information requires women who could become pregnant to use reliable contraception before and throughout treatment and for 6 weeks after the final dose. The implant should therefore remain in situ until that interval is complete, after which it can be removed if the rheumatology team is satisfied that her disease and replacement medication are compatible with pregnancy. A is incorrect because changing to a pregnancy-compatible regimen does not immediately eliminate residual reproductive risk from mycophenolate. B and C provide shorter intervals than the specified 6-week period; familiar 7-day contraceptive rules and 28-day drug-interaction rules do not apply to mycophenolate washout. E is unnecessarily prolonged for maternal exposure: 90-day advice applies to contraception following paternal mycophenolate exposure, not to a woman stopping the medicine. A longer delay could nevertheless be required for rheumatological reasons, such as demonstrating sustained disease control after changing treatment, but no such additional reason is present here.

Reference: CellCept 500 mg film-coated tablets — Summary of Product Characteristics (Text revised 8 April 2026) — https://www.medicines.org.uk/emc/product/1103/smpc Mycophenolate mofetil: guide for patients about risks to the unborn baby (MHRA approval June 2025) — https://www.medicines.org.uk/emc/rmm/106937/Document