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Psoriatic arthritis — SCE Rheumatology MCQ

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ModerateWeight ManagementPsoriatic arthritisSCE Rheumatology

A 36-year-old woman with psoriatic arthritis has low disease activity on methotrexate 20 mg once weekly and etanercept. She has a BMI of 37 kg/m² and hypertension. Following an inadequate response to a structured dietary and physical activity programme, a specialist weight-management service plans to start tirzepatide, with dose escalation at intervals of at least 4 weeks. She does not wish to become pregnant and takes a desogestrel progestogen-only pill consistently. A pregnancy test is negative. She has no vomiting or diarrhoea. Which is the most appropriate contraception advice when tirzepatide is started?

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

Reveal the answer and explanation

Correct answer: B — Switch to non-oral contraception, or add barrier contraception for 4 weeks after initiation and after each dose escalation

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

Tirzepatide delays gastric emptying and reduces exposure to an oral contraceptive after a single dose. In people with overweight or obesity, reduced contraceptive efficacy cannot be excluded. UK prescribing information and NICE safety advice therefore recommend either switching to a non-oral contraceptive method or adding a barrier method for 4 weeks after starting tirzepatide and for 4 weeks after every dose escalation. The effect on gastric emptying is greatest around initiation and dose increases. This is particularly important because methotrexate is embryotoxic and teratogenic; effective contraception is required throughout treatment. Continuing the oral method unchanged (A) provides insufficient reassurance. Precautions after dose escalation alone (B) omit the initial period of risk. Seven days (C) is shorter than the advised 4-week interval. Precautions for 4 weeks after initiation alone (D) fail to account for renewed uncertainty after each dose increase. The precaution need not necessarily continue without interruption throughout treatment: after each specified 4-week period, oral contraception can again be relied upon provided it is taken correctly and gastrointestinal illness has not compromised absorption.

Reference: Overweight and obesity management: tirzepatide local formulary information—Patient safety (23 December 2024) — https://www.nice.org.uk/guidance/ng246/resources/tirzepatide-local-formulary-information-13616789437/chapter/Patient-safety Mounjaro KwikPen 5 mg solution for injection in pre-filled pen—Summary of Product Characteristics (2026) — https://www.medicines.org.uk/emc/product/15482/smpc Methotrexate 10 mg Tablets—Summary of Product Characteristics (2022) — https://www.medicines.org.uk/emc/product/11723/smpc