What not to mix
Interactions
Alcohol, benzodiazepines, sleep meds, and other opioids can stack with morphine and stop breathing.
Highest-risk combinations
- Alcohol
- Benzodiazepines (examples: alprazolam, diazepam, lorazepam)
- Sleeping pills and other sedatives
- Other opioids, including cough syrups that contain them
- Muscle relaxers
Other clinically important interactions
- MAO inhibitors (or within 14 days of stopping them) — risk of serotonin syndrome and exaggerated opioid effects
- Mixed agonist/antagonist opioids (nalbuphine, butorphanol, pentazocine) can reduce pain relief and trigger withdrawal
- Anticholinergic drugs increase constipation and urinary retention, and can lead to ileus
- P-glycoprotein inhibitors (example: quinidine) can raise morphine exposure