Naltrexone Long Acting Formulations and Methods of Use

Abstract

The inventions described herein arose from unexpected discoveries made during clinical trials with a long acting formulation of naltrexone. As such, the invention includes a method for treating an individual in need of naltrexone comprising the step of parenterally administering a long acting formulation comprising naltrexone and to the use of naltrexone in the manufacture of medicaments for use in such methods.

What is claimed is: 
     
         1 . A method for treating an individual in need of naltrexone comprising the step of parenterally administering a long acting formulation comprising naltrexone to the individual wherein the serum AUC of naltrexone is at least about two times greater than that achieved by 50 mg/day oral administration. 
     
     
         2 . A method of treating an individual in need of naltrexone comprising administering a long acting formulation in a dose comprising between about 160 and 240 mg of naltrexone or about 310 to about 480 mg of naltrexone. 
     
     
         3 . A method of increasing the days prior to occurrence of alcohol consumption in an individual in need of naltrexone comprising administering a long acting formulation comprising naltrexone, in the absence of co-administering alcohol, to an individual who has not abstained from alcohol within three days, such as five days, prior to the naltrexone administration. 
     
     
         4 . A method of treating an individual in need of naltrexone comprising administering a long acting formulation comprising naltrexone in a dosage between about 160 mg to about 480 mg naltrexone every four weeks for a period of about 24 weeks or more wherein the individual has not used oral naltrexone within five days, such as within ten days, before said administration. 
     
     
         5 . The method of  claim 1  wherein the long acting formulation releases naltrexone for a period of at least two weeks. 
     
     
         6 . The method of  claim 1  wherein the long acting formulation releases naltrexone for a period of about four weeks. 
     
     
         7 . The method of  claim 1  wherein the long acting formulation is administered in a dose of at least about 160 mg of naltrexone. 
     
     
         8 . The method of  claim 1  wherein the long acting formulation is administered in a dose between about 160 and 240 mg of naltrexone. 
     
     
         9 . The method of  claim 8  wherein the long acting formulation is administered in a dose of about 190 mg of naltrexone. 
     
     
         10 . The method of  claim 1  wherein the long acting formulation is administered in a dose between about 310 and 480 mg of naltrexone. 
     
     
         11 . The method of  claim 1  wherein the long acting formulation is administered over a period of about 24 week period or longer. 
     
     
         12 . The method of  claim 1  further comprising a second administration of a long acting formulation comprising naltrexone at least about 7 days, preferably at least about 14 days, more preferably at least about 21 days, such as about 28 days, after the first administration. 
     
     
         13 . The method of  claim 12  wherein the second long acting formulation is the same as the first long acting formulation. 
     
     
         14 . The method of  claim 1  wherein the individual is an individual afflicted by alcohol dependency, such as a heavy drinker. 
     
     
         15 . The method of  claim 1  wherein naltrexone is administered by injection, such as intramuscularly or subcutaneously. 
     
     
         16 . The method of  claim 1  wherein the long acting formulation comprises a polylactide polymer or a poly lactic acid polymer. 
     
     
         17 . The method of  claim 1  wherein the long acting formulation comprises a polylactide-co-glycolide polymer, such as a polymer which possesses a molecular weight of at least 100,000 daltons. 
     
     
         18 . The method of  claim 1  wherein the naltrexone is present in the long acting formulation at a concentration of about 35% by weight.