Does Diazepam Interact with Fluoxetine Hydrochloride?
Diazepam and Fluoxetine Hydrochloride have a contraindicated drug interaction according to U.S. FDA drug labeling data. Monoamine Oxidase Inhibitors (MAOIs): (2.9 , 2.10 , 4.1 , 5.2 ) Drugs Metabolized by CYP2D6: Fluoxetine is a potent inhibitor of CYP2D6 enzyme pathway (7.7) Tricyclic Antidepressants (TCAs): Monitor TCA levels during coadministration with fluoxetine or when fluoxetine has been recently discontinued (5.2 , 7.7) CNS Acting Drugs: Caution should be used when taken in combination with other centrally acting drugs (7.2) Benzodiazepines: Diazepam - increased t½, alprazolam – further psychomotor performance decrement due to increased levels (7.7) Antipsychotics: Potential for elevation of haloperidol and clozapine levels (7.7) Anticonvulsants: Potential for elevated phenytoin and carbamazepine levels and clinical anticonvulsant toxicity (7.7) Serotonergic Drugs: (2.9 , 2.10 , 4.1 , 5.2) Drugs that Interfere with Hemostasis (e.g., NSAIDs, Aspirin, Warfarin): May potentiate the risk of bleeding (7.4) Drugs Tightly Bound to Plasma Proteins: May cause a shift in plasma concentrations (7.6 , 7.7) Olanzapine: When used in combination with fluoxetine, also refer to the Drug Interactions section of the package insert for Symbyax (7.7) Drugs that Prolong the QT Interval: Do not use fluoxetine with thioridazine or pimozide. Benzodiazepines — The half-life of concurrently administered diazepam may be prolonged in some patients [see Clinical Pharmacology (12.3) ] . Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This information is based on official FDA drug labeling sourced from OpenFDA and the NIH National Library of Medicine.
- Severity
- Contraindicated
- Diazepam Class
- Benzodiazepine
- Fluoxetine Hydrochloride Class
- Serotonin Reuptake Inhibitor
- Management
- Do not take together
- Data Source
- U.S. FDA via OpenFDA
What To Tell Your Doctor or Pharmacist
If you are taking Diazepam and your doctor is considering prescribing Fluoxetine Hydrochloride (or vice versa), make sure to:
- Inform your doctor and pharmacist of all current medications, including over-the-counter drugs and supplements
- Ask whether the benefits of combining these medications outweigh the risks for your specific situation
- Ask what symptoms to watch for that would indicate the interaction is causing problems
- Ask about alternative medications that do not interact with your current regimen
- Ask how frequently you should be monitored while these are co-prescribed
- Never stop or change either medication without first consulting your healthcare provider