Excretion of catecholamine metabolites during methadone maintenance and withdrawal.

Catecholamine metabolites excreted by long-term methadone hydrochloride-dependent subjects were studied in a protocol involving a two-study design. After a two-week methadone maintenance period, 15 subjects underwent abrupt methadone withdrawal and 12 subjects, gradual methadone withdrawal. The first study compared levels of catecholamine metabolites excreted during the stable methadone period with those excreted during the abrupt withdrawal period, as well as with those eliminated by healthy nonaddicted controls. No changes in the excretion of 3-methoxy-4-hydroxyphenylglycol and normetanephrine were noted between the methadone maintenance period and the time of abrupt methadone withdrawal. These values did not differ from those obtained for controls. However, higher levels of metanephreine were excreted during the stable methadone period than those in controls. During withdrawal, levels of metanephrine dropped a statistically significant amount in comparison with levels observed during the stable methadone period. The gradual withdrawal study confirmed these findings.