This study will evaluate the effects of multiple doses of MK-1439 (doravirine) on the pharmacokinetics of methadone in participants requiring methadone maintenance therapy. The primary hypothesis is that the Area Under the Concentration-Time curve to 24 hours (AUC0-24) of (R)-methadone is similar when a maintenance regimen of methadone is administered with or without multiple daily doses of MK-1439.