Induction with levomethadyl acetate: safety and efficacy.
BACKGROUND
Levomethadyl acetate hydrochloride (known as LAAM) is a mu-opioid agonist approved for the treatment of opioid dependence. Clinical trials comparing LAAM and methadone have reported lower patient retention rates during LAAM induction; however, this may reflect dose and schedule differences. Few studies have systematically examined LAAM dose induction. This study compared induction with 3 different LAAM dosage levels.


METHODS
In a randomized, double-blind trial, male and female opioid-dependent patients (N = 180) were assigned to 1 of 3 LAAM doses. The low-dose (25 mg) induction was constant from the onset of treatment, the medium-dose (50 mg) induction lasted 7 days, and the high-dose (100 mg) induction lasted 17 days. Safety and efficacy were assessed on retention, urinalysis and self-reported drug use, symptoms, and patient ratings of medication adequacy.


RESULTS
The high-dose group had significantly fewer illicit opioid-positive urine samples in weeks 3 and 4 as compared with the low-dose group. The high-dose group had significantly lower self-reported heroin craving in weeks 2 and 3. All groups demonstrated significant decreases in illicit drug use, withdrawal symptoms, and depression. There were no between-group differences in retention; however, there was a trend (P = .08) for lower retention and a greater number of agonist adverse effects were observed in the high-dose group. Overall, LAAM doses were well tolerated by most patients.


CONCLUSION
Induction with low and medium LAAM doses can be safely and effectively achieved within 7 days. Induction with higher LAAM doses can be safely achieved within 17 days, but may result in greater rates of patient dropout and opioid agonist adverse effects. Therefore, higher doses should be approached more slowly.