Drug interactions
Diphenhydramine + Papaveretum
Severity: Major
Diphenhydramine and Papaveretum: major interaction.
Last updated Sources: US FDA label
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
Papaveretum contains opium alkaloids including morphine, and diphenhydramine is a sedating antihistamine. Together they increase drowsiness, psychomotor impairment and the risk of respiratory depression.
What this interaction means in plain words
Diphenhydramine and Papaveretum can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
Additive CNS and respiratory depression from opioid agonism and central H1-receptor blockade.
What to do
Use the lowest effective doses and avoid in patients with respiratory compromise. Monitor sedation level and respiratory rate, and counsel patients against driving or drinking alcohol.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
Other interactions of Diphenhydramine
Frequently asked questions
Can I take Diphenhydramine with Papaveretum?
MediHelp rates the interaction as major. Diphenhydramine and Papaveretum can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Papaveretum contains opium alkaloids including morphine, and diphenhydramine is a sedating antihistamine. Together they increase drowsiness, psychomotor impairment and the risk of respiratory depression.
How serious is the interaction between Diphenhydramine and Papaveretum?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use the lowest effective doses and avoid in patients with respiratory compromise. Monitor sedation level and respiratory rate, and counsel patients against driving or drinking alcohol.
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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