Drug interactions
Clemastine + Primidone
Severity: Moderate
Clemastine 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
Both drugs cause sedation, so combining them can increase drowsiness, dizziness and psychomotor impairment. This is most relevant during primidone initiation or dose escalation and in older patients.
What this interaction means in plain words
Clemastine 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.
Clemastine belongs to Respiratory; Primidone belongs to Central Nervous System.
Why it happens
Additive CNS depression from H1-antihistamine sedation and primidone, which is metabolized to phenobarbital.
What to do
Monitor for oversedation and reduce doses if needed. Counsel patients to avoid driving and alcohol.
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 Clemastine
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 Clemastine with Primidone?
MediHelp rates the interaction as moderate. Clemastine 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. Both drugs cause sedation, so combining them can increase drowsiness, dizziness and psychomotor impairment. This is most relevant during primidone initiation or dose escalation and in older patients.
How serious is the interaction between Clemastine 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 for oversedation and reduce doses if needed. Counsel patients to avoid driving and alcohol.
What other medicines interact with Clemastine?
MediHelp also lists interactions of Clemastine with, for example, Alfentanil, Benzhydrocodone / acetaminophen, Buprenorphine buccal. The full list is on the Clemastine page.
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