Combining Diazepam and Fentanyl is a major interaction and should generally be avoided without close medical supervision.
The combination can lead to profound sedation, respiratory depression (decreased respiratory rate and depth), hypotension, psychomotor impairment, coma, and death. Patients may exhibit somnolence, confusion, dizziness, and difficulty arousing. The onset of these effects can be rapid and severe.
Mechanism: Both fentanyl (an opioid) and diazepam (a benzodiazepine) are central nervous system (CNS) depressants. Fentanyl acts primarily as a mu-opioid receptor agonist, while diazepam enhances the effect of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) at GABA-A receptors. The concomitant use of these agents leads to an additive and synergistic CNS depressant effect, significantly increasing the risk of respiratory depression.
Diazepam vs. Fentanyl
Compare Diazepam and Fentanyl: mechanism of action, indications, side effects, cost, and which may be right for you.
Quick Comparison
| Category | Diazepam | Fentanyl |
|---|---|---|
| Drug Class | Benzodiazepines | Opioid Analgesics |
| Rx Status | Rx | Rx |
| Generic Available | No | No |
| Typical Cost | $10–$50/month | $150–$600/month |
Diazepam Overview
Diazepam is a medication in the benzodiazepine class that works by calming the brain and nerves. It is primarily used to treat anxiety disorders, relieve symptoms of acute alcohol withdrawal, and help relax muscles to ease spasms.
Full Diazepam guide →Fentanyl Overview
FENTANYL (brand name: FENTANYL) is a Opioid Analgesics. 1 INDICATIONS AND USAGE Fentanyl transdermal system is indicated for the management of severe and persistent pain in opioid-tolerant patients, that requires an opioid analgesic and that cannot be adequately treated with alternative options, including immediate-release opioids. Patients considered…
Full Fentanyl guide →How Each Drug Works
Fentanyl
Fentanyl is an opioid agonist. Fentanyl interacts predominately with the opioid mu-receptor. These mu-binding sites are distributed in the human brain, spinal cord, and other tissues.
Approved Uses (Indications)
Diazepam
INDICATIONS AND USAGE Diazepam tablets are indicated for the management of anxiety disorders or for the short-term relief of the symptoms of anxiety. Anxiety or tension associated with the stress of everyday life usually does not require treatment with an anxiolytic. In acute alcohol withdrawal, diazepam tablets may be useful in the symptomatic relief of acute agitation, tremor, impending or acute delirium tremens and hallucinosis. Diazepam tablets are a useful adjunct for the relief of skeletal muscle spasm due to reflex spasm to local pathology (such as inflammation of the muscles or joints,…
Fentanyl
Fentanyl transdermal system is indicated for the management of severe and persistent pain in opioid-tolerant patients, that requires an opioid analgesic and that cannot be adequately treated with alternative options, including immediate-release opioids. Patients considered opioid-tolerant are those who are taking, for one week or longer, at least 60 mg morphine per day, 25 mcg transdermal fentanyl per hour, 30 mg oral oxycodone per day, 8 mg oral hydromorphone per day, 25 mg oral oxymorphone per day, 60 mg oral hydrocodone per day, or an equianalgesic dose of another op…
Side Effects
Diazepam
Fentanyl
Cost Comparison
Diazepam
$10–$50/month
Diazepam is available as a low-cost generic. Patients can often find significant savings by using discount cards or pharmacy coupon programs.
Fentanyl
$150–$600/month
As a brand-only medication, fentanyl can be expensive. Patients should check for manufacturer coupons or patient assistance programs, and compare prices at different pharmacies using discount cards.
Compare prices for Diazepam and Fentanyl
Check real-time pharmacy prices before you fill — free, no account needed.
Medical Disclaimer
The information on RxGuide is intended for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician, pharmacist, or other qualified health provider with any questions you may have regarding a medical condition or medication. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.