Neonatal methadone withdrawal. Effect of two treatment regimens.

Thirty-one infants exposed to methadone in utero who required pharmacologic treatment for withdrawal symptoms were randomly assigned to a paregoric or phenobarbital treatment group. Seven infants had symptoms too mild to require treatment. Respiratory rate, blood pH, PCO2, systolic BP, and serum thyroxine concentrations were measured on the 4th, 7th, and 14th days of life. Platelet counts were performed on the seventh and 14th days of life, and urinary catecholamine excretion was measured on the sixth day of life. Rates of weight gain were recorded during the second and third weeks of life. With the exception of a slightly higher blood PCO2 level in the phenobarbital-treated infants on day 7, no significant intergroup differences were observed in the treated infants. Paregoric-treated infants required a significantly longer period of treatment than phenobarbital-treated infants (22 v 17 days). This may have been due, at least in part, to the prolonged half-life and relatively high blood levels of phenobarbital present after cessation of therapy.