Drug interactions
Cevimeline + Diphenhydramine
Severity: Moderate
Cevimeline 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
Cevimeline is a muscarinic agonist used for dry mouth, and diphenhydramine blocks muscarinic receptors. The anticholinergic action of diphenhydramine can cancel out the salivary stimulation that cevimeline provides. Dry mouth may therefore persist or return.
What this interaction means in plain words
Cevimeline 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.
Cevimeline belongs to Miscellaneous; Diphenhydramine belongs to Respiratory.
Why it happens
Pharmacodynamic antagonism at muscarinic receptors.
What to do
Avoid anticholinergic antihistamines in patients treated for dry mouth and use a non-sedating antihistamine if needed. Assess response to cevimeline if an anticholinergic must continue.
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 Cevimeline
- Amitriptyline + Cevimeline Moderate
- Atenolol-chlorthalidone + Cevimeline Moderate
- Atenolol + Cevimeline Moderate
- Atropine + Cevimeline Moderate
- Betaxolol + Cevimeline Moderate
- Bethanechol + Cevimeline Moderate
Frequently asked questions
Can I take Cevimeline with Diphenhydramine?
MediHelp rates the interaction as moderate. Cevimeline 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. Cevimeline is a muscarinic agonist used for dry mouth, and diphenhydramine blocks muscarinic receptors. The anticholinergic action of diphenhydramine can cancel out the salivary stimulation that cevimeline provides. Dry mouth may therefore persist or return.
How serious is the interaction between Cevimeline 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 anticholinergic antihistamines in patients treated for dry mouth and use a non-sedating antihistamine if needed. Assess response to cevimeline if an anticholinergic must continue.
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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