Drug interactions
Carbamazepine + Primidone
Severity: Moderate
Carbamazepine 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 lower carbamazepine concentrations. Carbamazepine may also raise phenobarbital formation from primidone. Seizure control may be affected and sedation may change.
What this interaction means in plain words
Carbamazepine 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.
Carbamazepine belongs to Central Nervous System; Primidone belongs to Central Nervous System.
Why it happens
Phenobarbital derived from primidone induces CYP3A4 and other enzymes, accelerating carbamazepine metabolism.
What to do
Monitor carbamazepine and phenobarbital serum concentrations and clinical seizure control when starting or stopping either drug. Adjust carbamazepine dose as indicated.
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 Carbamazepine
- Artemether / lumefantrine + Carbamazepine Contraindicated
- Cabotegravir + Carbamazepine Contraindicated
- Carbamazepine + Delamanid Contraindicated
- Carbamazepine + Dienogest / estradiol valerate Contraindicated
- Carbamazepine + Doravirine Contraindicated
- Carbamazepine + Elbasvir / grazoprevir Contraindicated
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 Carbamazepine with Primidone?
MediHelp rates the interaction as moderate. Carbamazepine 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 lower carbamazepine concentrations. Carbamazepine may also raise phenobarbital formation from primidone. Seizure control may be affected and sedation may change.
How serious is the interaction between Carbamazepine 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 carbamazepine and phenobarbital serum concentrations and clinical seizure control when starting or stopping either drug. Adjust carbamazepine dose as indicated.
What other medicines interact with Carbamazepine?
MediHelp also lists interactions of Carbamazepine with, for example, Artemether / lumefantrine, Cabotegravir, Delamanid. The full list is on the Carbamazepine page.
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