Drug interactions
Doxylamine + Primidone
Severity: Moderate
Doxylamine 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 metabolised to phenobarbital and causes sedation. Doxylamine adds to drowsiness and psychomotor impairment.
What this interaction means in plain words
Doxylamine 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.
Doxylamine belongs to Respiratory; Primidone belongs to Central Nervous System.
Why it happens
Additive CNS depression via barbiturate GABA-A potentiation and H1 antagonism.
What to do
Avoid regular doxylamine use where possible. Monitor sedation and counsel on driving.
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 Doxylamine
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 Doxylamine with Primidone?
MediHelp rates the interaction as moderate. Doxylamine 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 metabolised to phenobarbital and causes sedation. Doxylamine adds to drowsiness and psychomotor impairment.
How serious is the interaction between Doxylamine 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: Avoid regular doxylamine use where possible. Monitor sedation and counsel on driving.
What other medicines interact with Doxylamine?
MediHelp also lists interactions of Doxylamine with, for example, Belladonna and opium, Benzhydrocodone / acetaminophen, Brexanolone. The full list is on the Doxylamine page.
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