Drug interactions
Calcium / magnesium / potassium / sodium oxybates + Diphenhydramine
Severity: Major
Calcium / magnesium / potassium / sodium oxybates and Diphenhydramine: major 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
Oxybates strongly depress the CNS and respiration. Diphenhydramine adds sedation, increasing the risk of profound sedation, respiratory depression and coma.
What this interaction means in plain words
Calcium / magnesium / potassium / sodium oxybates and Diphenhydramine 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 depression through pharmacodynamic synergism.
What to do
Avoid the combination where possible; if unavoidable, minimize doses and monitor for sedation and respiratory depression.
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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Other interactions of Diphenhydramine
Frequently asked questions
Can I take Calcium / magnesium / potassium / sodium oxybates with Diphenhydramine?
MediHelp rates the interaction as major. Calcium / magnesium / potassium / sodium oxybates and Diphenhydramine 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. Oxybates strongly depress the CNS and respiration. Diphenhydramine adds sedation, increasing the risk of profound sedation, respiratory depression and coma.
How serious is the interaction between Calcium / magnesium / potassium / sodium oxybates and Diphenhydramine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible; if unavoidable, minimize doses and monitor for sedation and respiratory depression.
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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