Lofexidine and Methylnaltrexone interaction
Lofexidine and Methylnaltrexone: the Lofexidine prescribing label describes an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Lofexidine label · effective 2026-07-22
Oral Naltrexone : Concomitant use may reduce efficacy of oral naltrexone.
It is possible that oral naltrexone efficacy may be reduced if used concomitantly within 2 hours of Lofexidine tablets.
Oral Naltrexone Coadministration of Lofexidine tablets and oral naltrexone resulted in statistically significant differences in the steady-state pharmacokinetics of naltrexone.
This interaction is not expected if naltrexone is administered by non-oral routes [see Clinical Pharmacology (12.3) ] .
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.