Drug interactions
Diazepam + Quetiapine
Severity: Moderate
Diazepam and Quetiapine: 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
Both agents cause sedation, so their combination can intensify drowsiness, slowed reaction time and impaired coordination. Orthostatic hypotension and falls are additional concerns, particularly in elderly patients.
What this interaction means in plain words
Diazepam and Quetiapine 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.
Diazepam belongs to Musculoskeletal; Quetiapine belongs to Central Nervous System.
Why it happens
Additive CNS depression from GABA-A potentiation by diazepam and histamine H1 and alpha-1 blockade by quetiapine.
What to do
Start with the lowest effective doses and monitor for oversedation and orthostatic hypotension. Advise patients to avoid driving and alcohol until the response is known.
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 Diazepam
Other interactions of Quetiapine
- Adagrasib + Quetiapine Major
- Amiodarone + Quetiapine Major
- Amisulpride + Quetiapine Major
- Amoxapine + Quetiapine Major
- Anagrelide + Quetiapine Major
- Apalutamide + Quetiapine Major
Frequently asked questions
Can I take Diazepam with Quetiapine?
MediHelp rates the interaction as moderate. Diazepam and Quetiapine 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. Both agents cause sedation, so their combination can intensify drowsiness, slowed reaction time and impaired coordination. Orthostatic hypotension and falls are additional concerns, particularly in elderly patients.
How serious is the interaction between Diazepam and Quetiapine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Start with the lowest effective doses and monitor for oversedation and orthostatic hypotension. Advise patients to avoid driving and alcohol until the response is known.
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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