Drug interactions
Butabarbital + Diphenhydramine
Severity: Moderate
Butabarbital 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
Butabarbital is a barbiturate sedative-hypnotic, and diphenhydramine is a sedating antihistamine. Used together they produce additive central nervous system depression with marked drowsiness, confusion, impaired coordination and sometimes respiratory depression. Older and frail patients are at greater risk of falls and of delirium.
What this interaction means in plain words
Butabarbital 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.
Why it happens
Additive central nervous system depression from GABA-A potentiation by the barbiturate and central H1 receptor blockade.
What to do
Avoid combining where possible. If both are used, give the lowest effective doses, monitor level of consciousness and breathing, and warn against alcohol and 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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Butabarbital and Diphenhydramine, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Diphenhydramine
Frequently asked questions
Can I take Butabarbital with Diphenhydramine?
MediHelp rates the interaction as moderate. Butabarbital 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. Butabarbital is a barbiturate sedative-hypnotic, and diphenhydramine is a sedating antihistamine. Used together they produce additive central nervous system depression with marked drowsiness, confusion, impaired coordination and sometimes respiratory depression. Older and frail patients are at greater risk of falls and of delirium.
How serious is the interaction between Butabarbital 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 combining where possible. If both are used, give the lowest effective doses, monitor level of consciousness and breathing, and warn against alcohol and driving.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
