The present invention is directed to oral, therapeutically effective modified release pharmaceutical compositions of (-)-17-(cyclobutylmethyl)morphinan-3,14-diol and it pharmaceutically acceptable salts and the use thereof, including delayed onset and extended release dosage forms. The present invention is also directed at modified release dosage forms of oral (-)-17-(cyclobutylmethyl)morphinan-3,14-diol which provide robust efficacy and reduced potential for abuse and misuse.
