MinorAnalgesics and antipyretics. Pyrazolones×Anilides. Analgesics and antipyretics
Updated · Methodology
Mechanism
Neither is an NSAID and their mechanisms do not overlap, so the pair is used to cover peaks of pain or fever by alternating doses. Metamizole induces CYP2B6 and CYP3A4, pathways that do not govern paracetamol metabolism, so the two do not alter each other.
Symptoms
The pair creates no distinct picture. The paracetamol ceiling stays at 4 g a day, and metamizole is limited by haematological risk: recurring fever, sore throat or mouth ulcers during treatment point to agranulocytosis rather than to the infection being treated.
Management
Alternate every 4-6 hours, counting each daily dose separately. Metamizole goes in short courses because of its haematological profile; paracetamol stays under 4 g, and lower with liver disease, low weight or regular alcohol use.
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.
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Sources
- AEMPS: Ficha técnica Paracetamol Abamed 1 g comprimidos EFG (2020)– AEMPS, CIMA, nº registro 77758, secciones 4.2 y 4.5
- AEMPS: Ficha técnica Metamizol Cinfa 575 mg cápsulas duras EFG (2024)– AEMPS, CIMA, nº registro 68116, sección 4.5
- AEMPS: Metamizol y riesgo de agranulocitosis: conclusiones de la evaluación europea (2018)– AEMPS, nota informativa MUH (FV), 15/2018