Drug interactions
Amifampridine + Diphenhydramine
Severity: Moderate
Amifampridine and Diphenhydramine: 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
Amifampridine causes dose-related seizures. Diphenhydramine can lower the seizure threshold, particularly at high doses or in overdose, which may increase the seizure risk.
What this interaction means in plain words
Amifampridine and Diphenhydramine 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.
Amifampridine belongs to Central Nervous System; Diphenhydramine belongs to Respiratory.
Why it happens
Additive lowering of seizure threshold through pharmacodynamic effects.
What to do
Avoid regular diphenhydramine use where possible and select a non-sedating antihistamine if needed. Monitor for seizure activity and use the lowest effective amifampridine dose.
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 Diphenhydramine
Other interactions of Amifampridine
- Amifampridine + Bupropion-naltrexone Major
- Amantadine + Amifampridine Moderate
- Amifampridine + Amitriptyline Moderate
- Amifampridine + Baclofen Moderate
- Amifampridine + Bethanechol Moderate
- Amifampridine + Bromocriptine Moderate
Frequently asked questions
Can I take Amifampridine with Diphenhydramine?
MediHelp rates the interaction as moderate. Amifampridine and Diphenhydramine 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. Amifampridine causes dose-related seizures. Diphenhydramine can lower the seizure threshold, particularly at high doses or in overdose, which may increase the seizure risk.
How serious is the interaction between Amifampridine and Diphenhydramine?
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 diphenhydramine use where possible and select a non-sedating antihistamine if needed. Monitor for seizure activity and use the lowest effective amifampridine dose.
What other medicines interact with Diphenhydramine?
MediHelp also lists interactions of Diphenhydramine with, for example, Alfentanil, Belladonna and opium, Benzhydrocodone / acetaminophen. The full list is on the Diphenhydramine page.
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