The effects of gabapentin on methadone based addiction treatment: a randomized controlled trial.

Gabapentin is a potentially useful drug in alleviating the hyperexcitatory painful states in the control of opiate dependence in acute detoxification and the stabilization phase. This study aim was to evaluate the effectiveness of gabapentin adds-on methadone therapy on lowering the methadone. This randomized double blind controlled clinical trial conducted at an outpatient rehabilitation clinic. Sixty patients using opium, opium extract and heroin were randomly assigned to two groups (34 in treatment group and 26 in control group); one group was prescribed combination of methadone (40-120 mg) and gabapentin (300 mg) as group A, and the other group was given methadone (40-120) and placebo as group B. The subjects were followed up for three weeks after intervention. There were 60 outpatients including 51 males with the mean age of 40.9±9.2. Daily dose and cumulative dose of methadone during the treatment was found to be significantly higher in group B (73.8±19.5 mg daily vs. 58.9±11 mg daily and cumulatively 1550.7±409.7 mg vs. 238.3±238.2 mg, p= 0.001). When the patients were stratified based on the kind of abused drug, the methadone dose was seen to be significantly reduced in the opium addicted patients in the group A. Group A showed more withdrawal symptoms whereas the most common complain of group B was sedation particularly during the first three days. The results showed that gabapentin is an effective adds-on therapy when is added to methadone. This drug leads to relief of withdrawal symptoms and lower methadone consumption.