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Citalopram QT prolongation — GPhC CRA MCQ

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HardCNS TherapeuticsCitalopram QT prolongationGPhC CRA

A 69-year-old woman taking citalopram 40mg daily is prescribed erythromycin for a chest infection. She has hypokalaemia from bendroflumethiazide and an ECG last month showed QTc 480ms. What is the most appropriate action?

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Correct answer: B — Contact the prescriber to avoid additive QT prolongation risk

Citalopram and erythromycin can both prolong the QT interval, and this patient has additional risk factors including hypokalaemia and a previously prolonged QTc. The combination should be queried before supply. Spacing doses does not remove the QT risk. Potassium correction may be needed but should not be managed solely with OTC advice in this context. The keyed option is to contact the prescriber before supply because additive QT prolongation is unsafe.

Reference: https://www.pharmacyregulation.org/registration-assessment#stage-8-order-100