skip to main content

FGA to SGA Depot Switch — MRCPsych Paper B MCQ

Instant feedback + full explanation. One question, done properly.

ModerateSchizophrenia & PsychosisFGA to SGA Depot SwitchMRCPsych Paper B

A 34-year-old man with schizophrenia has remained relapse-free for 18 months on flupentixol decanoate. He has developed persistent symmetrical rigidity, bradykinesia and resting tremor. These symptoms began after depot treatment, and there was no preceding movement disorder. They remain functionally disabling despite reducing the depot to the lowest effective licensed dose. He wishes to continue long-acting injectable treatment because previous missed oral doses led to relapse, but he wants to avoid long-term anticholinergic medication. What is the most appropriate next step?

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

Reveal the answer and explanation

Correct answer: D — Switch to an SGA long-acting injectable selected jointly for a more favourable EPS profile

The correct answer is D. The temporal relationship, symmetrical rigidity, bradykinesia and tremor indicate antipsychotic-induced parkinsonism. It remains disabling despite dose reduction, while an LAI remains clinically important because oral non-adherence previously caused relapse. NICE recommends individualised antipsychotic selection that explicitly considers extrapyramidal adverse effects; switching to an SGA LAI with a more favourable EPS profile is therefore appropriate. This is not a class-wide guarantee: paliperidone can cause EPS, and aripiprazole can cause akathisia, so the specific drug requires shared risk-benefit assessment. Increasing the FGA dose is likely to worsen EPS. Long-term high-dose procyclidine adds anticholinergic burden and does not address the cause. Accepting disabling EPS is inappropriate, while abrupt cessation without replacement creates substantial relapse risk.

Reference: NICE. Psychosis and schizophrenia in adults: prevention and management (CG178), recommendations 1.3.5.1, 1.3.6.3 and 1.5.6.1. 2014, current online version. https://www.nice.org.uk/Guidance/CG178/chapter/recommendations