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A controlled study investigated the relationship between steady-state plasma and RBC concentrations of the phenothiazine derivative butaperazine maleate and the therapeutic response in 24 hospitalized schizophrenic patients who received constant maintenance doses of butaperazine during the first two weeks of treatment. Butaperazine concentrations in RBCs correlated significantly with clinical improvement in an inverted U-shaped pattern, whereas plasma levels of butaperazine were not significantly related to clinical response. Both plasma and RBC levels of butaperazine showed large interpatient variations. The level of RBC-bound drug might be a better peripheral correlate of drug levels in the brain than are drug levels in plasma. Thus, monitoring drug levels in RBCs might have an advantage over measured drug levels in plasma. These findings might not allow generalization to other antipsychotic agents.

Urinary catecholamine levels were measured in 25 anorexia nervosa patients at the time when they were acutely ill with secondary depressive symptoms and again after treatment and weight gain to see whether changes in weight, activity levels, and symptoms of depression occurring during treatment might be associated with changes in urinary 3-methoxy-4-hydroxyphenylglycol (MHPG) concentrations. The latter was significantly lower in the acutely ill anorectics than in the control group. An increase in urinary MHPG concentration after treatment was significantly correlated with a decrease in depressive symptomatology. The increase in urinary MHPG level during treatment did not correlate significantly with change in patient's activity level. There seems to be a relationship between MHPG and the symptom of depression in a group of patients who do not carry a primary diagnosis of depression.

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.

Pharmacokinetics of the phenothiazine, butaperazine, were studied in relationship to acute dystonic reactions. Dystonias appeared on falling drug concentrations, more than one half-life after plasma and red blood cell (RBC) peak butaperazine concentrations. Red blood cell butaperazine kinetics differentiated better than did plasma butaperazine levels those subjects in whom dystonias would develop from those in whom they did not. We conclude that RBC phenothiazine levels may more clearly reflect drug concentration at critical brain sites than do simple plasma drug levels. Furthermore, dystonic reactions may be the result of differential sensitivity of two or more receptor systems to receptor blockade by antischizophrenic agents.

Blood levels of butaperazine were measured in schizophrenic patients who were chronic nonresponders to their psychotropic medication. The blood levels were compared with those in patients who had shown a better clinical response to this neuroleptic. Nonresponders had two to seven times lower levels of butaperazine in plasma and RBCs after a single dose or chronic dosing. Some of the patients later treated with thioridazine or haloperidol had lower plasma levels of these neuroleptics also. No significant differences were found between nonresponders and relative responders in either the alpha- or beta-phase half-life of butaperazine in plasma and RBCs after administration of a single dose of the drug. Butaperazine and thioridazine levels were not related to previously administered amounts of neuroleptic drugs. These findings do not support the hypothesis that low blood levels are the result of faster systemic metabolism of the drug after it reaches the central circulation. Our results suggest that low blood levels of neuroleptics may be one important factor in the poor clinical response of some chronic schizophrenic patients.