Omeprazole and Diazepam Nasal Spray: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Diazepam Nasal Spray
Omeprazole
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Increased diazePAM exposure
Interaction Deep Dive
Concomitant administration of omeprazole with diazePAM may increase the exposure of diazePAM. Monitor patients for increased sedation and reduce the dose of diazePAM as needed2. Concurrent use of diazePAM and omeprazole has been reported to slow diazePAM metabolism and delay its elimination, thereby resulting in enhanced and prolonged benzodiazepine effects 641. One study indicated that decreased diazePAM clearance occurred in almost one-half of patients who were fast metabolizers of omeprazole but the combination had little significance in slow metabolizers of omeprazole 3.
Why it happens (mechanism)
Inhibition of CYP2C19-mediated metabolism of diazePAM
Literature reports
5 reports — tap to read
a) Concomitant administration of omeprazole 20 mg once daily and diazePAM 0.1 mg/kg given intravenously resulted in 27% decrease in clearance and 36% increase in diazePAM half-life 2.
b) In a double blind, crossover study, the addition of omeprazole in patients taking diazePAM resulted in a 25% to 50% reduction in diazePAM clearance. This interaction occurred in about 40% of patients who were fast metabolizers of omeprazole. In slow metabolizers, this interaction was of little significance 3.
c) Concomitant administration of diazePAM and omeprazole resulted in a 130% increase in mean elimination half-life of diazePAM and subsequent increases in plasma diazePAM concentrations 4.
d) DiazePAM is metabolized by the cytochrome P450 enzyme system. Omeprazole was reported to inhibit individual enzymes in the P450 system in studies of combined omeprazole and diazePAM in vitro and in vivo both in animals and humans 1.
e) Human liver microsomes were used to study the metabolism of diazePAM to its two major metabolites nordiazepam (NDZ) and 3-hydroxydiazepam (3-HDZ). In addition, inhibition of these two pathways by omeprazole and omeprazole sulfone was studied. Omeprazole sulfone inhibited both pathways comparably; however, NDZ pathway was less susceptible to omeprazole inhibition 5.
Common questions
Can I take Omeprazole and Diazepam Nasal Spray together?
Increased diazePAM exposure Always confirm with your pharmacist or prescriber before making any change.
How serious is the Omeprazole and Diazepam Nasal Spray interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
How strong is the evidence for this interaction?
The evidence is graded "probable". Good supporting evidence, though not definitively proven.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Omeprazole or Diazepam Nasal Spray need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (6)
- von Herrath D & Thimme W: Wechselwirkungen von omeprazole und cimetidine mit diazepam. Der Arzneimittelbrief 1993; 27:87.
- Product Information: KONVOMEP(TM) powder for oral suspension, omeprazole sodium bicarbonate powder for oral suspension. Azurity Pharmaceuticals Inc (per manufacturer), Woburn, MA, 2022. DailyMed
- Andersson T, Cederberg C, Edvardsson G, et al: Effect of omeprazole treatment on diazepam plasma levels in slow versus normal rapid metabolizers of omeprazole. Clin Pharmacol Ther 1990; 47:79-85. PubMed
- Gugler R & Jensen JC: Omeprazole inhibits elimination of diazepam (letter). Lancet 1984; 1:969. DOI
- Zomorodi K & Houston JB: Diazepam-omeprazole inhibition interaction: an in vitro investigation using human liver microsomes. Br J Clin Pharmacol 1996; 2:157-162.
- Product Information: Prilosec(R), omeprazole. Astra Merck Inc. Wayne, PA, 1997. DailyMed
Keep reading about Diazepam Nasal Spray
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