Alvimopan and Fentanyl interaction
Alvimopan and Fentanyl: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Alvimopan label · effective 2024-02-02
Alvimopan capsules are contraindicated in patients who have taken therapeutic doses of opioids for more than 7 consecutive days immediately prior to taking alvimopan capsules [see Warnings and Precautions ( 5.3 )].
Patients who have taken therapeutic doses of opioids for more than 7 consecutive days prior to taking alvimopan capsules.
Alvimopan is contraindicated in patients who have taken therapeutic doses of opioids for more than 7 consecutive days immediately prior to taking alvimopan [see Contraindications ( 4) ].
Myocardial Infarction: A higher number of myocardial infarctions was reported in patients treated with alvimopan 0.5 mg twice daily compared with placebo in a 12-month study in patients treated with opioids for chronic non-cancer pain, although a causal relationship with long-term use has not been established.
Potential Risk of Myocardial Infarction with Long-Term Use There were more reports of myocardial infarctions in patients treated with alvimopan 0.5 mg twice daily compared with placebo-treated patients in a 12-month study of patients treated with opioids for chronic non-cancer pain (alvimopan 0.5 mg, n=538; placebo, n=267).
From the Fentanyl (FENTANYL CITRATE) label · effective 2026-04-07
Management of respiratory depression may include close observation, supportive measures, and use of opioid overdose reversal agents (e.g., naloxone, nalmefene) , depending on the patient's clinical status [see Overdosage (10) ] .
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.