Drug interactions
Erythromycin + Primidone
Severity: Moderate
Erythromycin 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 is metabolized to phenobarbital, which induces CYP3A4 and can reduce erythromycin concentrations and efficacy. Erythromycin may also raise levels of anticonvulsants metabolized by CYP3A4.
What this interaction means in plain words
Erythromycin 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.
Erythromycin belongs to Anti Bacterial; Primidone belongs to Central Nervous System.
Why it happens
Primidone and its metabolite phenobarbital induce CYP3A4, increasing erythromycin clearance.
What to do
Monitor antibiotic response and consider a non-CYP3A4-dependent alternative for serious infections. Monitor for signs of anticonvulsant toxicity.
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 Erythromycin
- Conivaptan + Erythromycin Contraindicated
- Dihydroergotamine intranasal + Erythromycin Contraindicated
- Dihydroergotamine + Erythromycin Contraindicated
- Domperidone + Erythromycin Contraindicated
- Dronedarone + Erythromycin Contraindicated
- Droperidol + Erythromycin 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 Erythromycin with Primidone?
MediHelp rates the interaction as moderate. Erythromycin 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 is metabolized to phenobarbital, which induces CYP3A4 and can reduce erythromycin concentrations and efficacy. Erythromycin may also raise levels of anticonvulsants metabolized by CYP3A4.
How serious is the interaction between Erythromycin 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 antibiotic response and consider a non-CYP3A4-dependent alternative for serious infections. Monitor for signs of anticonvulsant toxicity.
What other medicines interact with Erythromycin?
MediHelp also lists interactions of Erythromycin with, for example, Conivaptan, Dihydroergotamine intranasal, Dihydroergotamine. The full list is on the Erythromycin page.
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