Drug interactions
Diphenhydramine + Methohexital
Severity: Moderate
Diphenhydramine and Methohexital: 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
Methohexital is a barbiturate anesthetic, and diphenhydramine adds sedative effects. Together they may deepen sedation and increase respiratory and cardiovascular depression.
What this interaction means in plain words
Diphenhydramine and Methohexital 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.
Diphenhydramine belongs to Respiratory; Methohexital belongs to Central Nervous System.
Why it happens
Additive CNS depression.
What to do
Titrate methohexital to effect with reduced doses and monitor airway, oxygenation and blood pressure. Ensure resuscitation facilities are available.
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 Methohexital
Frequently asked questions
Can I take Diphenhydramine with Methohexital?
MediHelp rates the interaction as moderate. Diphenhydramine and Methohexital 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. Methohexital is a barbiturate anesthetic, and diphenhydramine adds sedative effects. Together they may deepen sedation and increase respiratory and cardiovascular depression.
How serious is the interaction between Diphenhydramine and Methohexital?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Titrate methohexital to effect with reduced doses and monitor airway, oxygenation and blood pressure. Ensure resuscitation facilities are available.
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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