Is concentration controlled treatment of self-injury in autism with naltrexone (Revia) documented?

Fråga: Is concentration controlled treatment of self-injury in autism with naltrexone (Revia) documented? The background to the question is a male autistic patient displaying infliction of self injury in whom naltrexone treatment 5 mg twice daily commenced recently.

Sammanfattning: There are presently no data supporting the use of plasma concentration monitoring to control naltrexone therapy.

Svar: While the main indication for naltrexone is in the treatment of alcoholism, both systematic (n=41) and case studies of the drug in autism have been carried out (1,2,3). The apparent effects on the autistic syndrome is on hyperactivity (2) and self injury (1). There are several analytical methods for naltrexone and mass-spectrometry coupled to gas-chromatography (4) has been used to study concentration-effect relationship (5) in autistic children and in concentration side-effect studies in adult alcohol dependent patients (6). In a study of autistic children, the variation in plasma concentration among individuals was almost 50-fold (5) while the overall effect of naltrexone on autism-related hyperactivity was statistically significant but small. Such circumstances make it difficult to establish a therapeutic interval, also in principle. Because naltrexone acts by binding to u-opioid receptors, also its pharmacological target is subject to considerable variability in sensitivity. Taken together, there is no solid ground for doing concentration controlled treatment with naltrexone. Possibly, plasma monitoring can be worthwhile in a compliance problem.

Naltrexone is not routinely analysed by the Swedish pharmacological laboratories.