MajorFirst-generation antipsychotics. Butyrophenone derivatives×Atypical antipsychotics
Updated · Methodology
Mechanism
Dual antipsychotic therapy – additive risk of extrapyramidal symptoms, sedation, QT prolongation, and metabolic side effects. Polypharmacy without therapeutic rationale in most cases.
Symptoms
Sedation, extrapyramidal symptoms (tremor, rigidity, akathisia), QT prolongation on ECG. Metabolic effects: weight gain, dyslipidaemia (from quetiapine).
Management
Avoid the combination. Choose one antipsychotic: quetiapine for schizophrenia with anxious-depressive component or bipolar disorder; haloperidol for acute psychotic agitation. If dual therapy is needed, restrict to short-term use during acute psychotic episodes.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
Summary of a multi-drug list →
Medicine list: everything you take in one place →
Sources
- FDA: Seroquel (quetiapine) prescribing information (2017)– ; DailyMed setid 8ae62aaf-f8c5-417f-baac-0098369ca322
- AEMPS: Ficha técnica: Quetiapina (nº registro 72882), sección 4.5 (2024)– AEMPS, CIMA, nº registro 72882, sección 4.5