Drug interactions
Diazepam + Olanzapine
Severity: Major
Diazepam and Olanzapine: 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
Combined use increases sedation and can cause orthostatic hypotension, and respiratory or cardiovascular depression has been reported, mainly with parenteral olanzapine given with a benzodiazepine. Caution is greatest with intramuscular olanzapine.
What this interaction means in plain words
Diazepam and Olanzapine 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.
Diazepam belongs to Musculoskeletal; Olanzapine belongs to Central Nervous System.
Why it happens
Additive CNS depression and hypotensive effects.
What to do
Avoid giving intramuscular olanzapine and parenteral benzodiazepines close together; if both are needed, monitor vital signs and sedation. With oral therapy, use the lowest effective doses and monitor for sedation and orthostasis.
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 Diazepam
Other interactions of Olanzapine
Frequently asked questions
Can I take Diazepam with Olanzapine?
MediHelp rates the interaction as major. Diazepam and Olanzapine 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. Combined use increases sedation and can cause orthostatic hypotension, and respiratory or cardiovascular depression has been reported, mainly with parenteral olanzapine given with a benzodiazepine. Caution is greatest with intramuscular olanzapine.
How serious is the interaction between Diazepam and Olanzapine?
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 giving intramuscular olanzapine and parenteral benzodiazepines close together; if both are needed, monitor vital signs and sedation. With oral therapy, use the lowest effective doses and monitor for sedation and orthostasis.
What other medicines interact with Diazepam?
MediHelp also lists interactions of Diazepam with, for example, Calcium / magnesium / potassium / sodium oxybates, Alfentanil, Alprazolam. The full list is on the Diazepam page.
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