Drug interactions
Losartan + Primidone
Severity: Moderate
Losartan and Primidone: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Primidone, and its metabolite phenobarbital, induce hepatic enzymes and can increase losartan clearance. This may lower exposure to losartan and its active metabolite and weaken blood pressure control.
What this interaction means in plain words
Losartan and Primidone can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Losartan belongs to Cardiovascular; Primidone belongs to Central Nervous System.
Why it happens
Enzyme induction (CYP3A4 and CYP2C9) by phenobarbital increases losartan metabolism.
What to do
Monitor blood pressure after starting or stopping primidone and titrate the losartan dose accordingly.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Losartan
- Aliskiren + Losartan Contraindicated
- Losartan + Sparsentan Contraindicated
- Amifostine + Losartan Major
- Amiloride + Losartan Major
- Amlodipine-benazepril + Losartan Major
- Amlodipine-hydrochlorothiazide-valsartan + Losartan Major
Other interactions of Primidone
- Lorlatinib + Primidone Contraindicated
- Lurasidone + Primidone Contraindicated
- Primidone + Ranolazine Contraindicated
- Primidone + Sofosbuvir-velpatasvir-voxilaprevir Contraindicated
- Primidone + Voriconazole Contraindicated
- Abiraterone + Primidone Major
Frequently asked questions
Can I take Losartan with Primidone?
MediHelp rates the interaction as moderate. Losartan and Primidone can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Primidone, and its metabolite phenobarbital, induce hepatic enzymes and can increase losartan clearance. This may lower exposure to losartan and its active metabolite and weaken blood pressure control.
How serious is the interaction between Losartan and Primidone?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood pressure after starting or stopping primidone and titrate the losartan dose accordingly.
What other medicines interact with Losartan?
MediHelp also lists interactions of Losartan with, for example, Aliskiren, Sparsentan, Amifostine. The full list is on the Losartan page.
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