Methods for overcoming resistance to tramadol

Abstract

There is disclosed a method for treating disorders modulated by at least opiate receptor activity or monoamine activity, including acute and chronic pain, comprising administering a pharmaceutical formulation comprising O-desmethyltramadol. Methods are also provided that are effective for overcoming resistance to tramadol in patients.

What is claimed: 
     
         1 . A method for treating a disorder modulated at least in part by opiate receptor activity or monoamine activity, comprising orally administering every six hours to a subject in need thereof a pharmaceutical composition consisting of a therapeutically effective amount of an active pharmaceutical ingredient and pharmaceutically acceptable carriers in a sustained release dosage form, wherein the active pharmaceutical ingredient consists of O-desmethyltramadol (M1), or a pharmaceutically acceptable salt thereof, wherein the pharmaceutically acceptable carriers consist of a polymer selected from polysaccharide, acrylic resin, polyalkylene glycol, polyvinyl acetate, polyvinylpyrrolidone, protein-derived materials, colloidal silica, and mixtures thereof, microcrystalline cellulose; and, optionally, one or more pharmaceutical excipients selected from the group consisting of preservatives, buffers, salts and magnesium stearate; and wherein the mean difference between minimum and maximum plasma concentration of M1 at steady state (ΔCss) is not more than 40 ng/ml.