Diazepam is a benzodiazepine used for anxiety, muscle spasms, seizures, and alcohol withdrawal syndrome.
Also known as: diazepam, valium
SSRI + benzodiazepine: additive sedative effect and fall risk.
Fluoxetine moderately inhibits CYP2C19 and CYP3A4, metabolic pathways for diazepam. Diazepam levels may increase slightly, prolonging sedation. The effect is generally modest. Monitor sedation and respiratory function, especially in the elderly. Consider switching diazepam to lorazepam (not metabolised by CYP) or alprazolam (metabolised by CYP3A4 but with short half-life).
SSRI + benzodiazepine: fluoxetine may inhibit diazepam metabolism (CYP2C19/3A4). Prolonged sedation.
Additive CNS effect — sedation, cognitive impairment, fall risk (especially elderly). Fluoxetine may inhibit diazepam metabolism via CYP3A4.
Sedation, coordination, falls.
Falls with fractures in the elderly.
Start with low benzodiazepine dose. Re-evaluate need for combination.
DailyMed/FDA
Benzodiazepine + CYP3A4 inhibitor: diazepam levels increased. Prolonged sedation.
Ritonavir inhibits CYP3A4, the main metabolic pathway for diazepam. Levels may increase significantly, prolonging sedation. Monitor sedation and respiratory function. Reduce diazepam dose by 50%. Consider switching to lorazepam (not metabolised by CYP) or midazolam (short-acting).
Benzodiazepine + CYP3A4 inhibitor: ritonavir may increase diazepam levels. Prolonged sedation.
Ritonavir inhibits CYP3A4, the main metabolic pathway for diazepam. Levels may increase significantly, prolonging sedation.
Sedation, respiratory rate.
Respiratory depression.
Reduce diazepam dose by 50%. Monitor sedation and respiratory function.
DailyMed/FDA
No documented food or drink interactions.
No documented disease interactions.
No documented pregnancy or breastfeeding information.
Clinical and educational support tool. The information does not replace a medical prescription or the opinion of a qualified healthcare professional.
Long half-life benzodiazepine. GABA-A agonist.
Binding to the benzodiazepine site of the GABA-A receptor → potentiation of GABA effect → increased neuronal inhibition.
Rapid and complete oral absorption. Bioavailability: 100%.
Metabolised by CYP3A4 and CYP2C19 to desmethyldiazepam (active, half-life 100 h), oxazepam and temazepam.
20-100 h (with active metabolites: up to 200 h).
Medicines from the same therapeutic group (ATC classification) or the same pharmacological class.
