Physiologic and clinical effects of chlorpromazine and their relationship to plasma levelTen patients suffering from functional psychoses who had not received medication for one month were studied. After investigation before treatment, they received chlorpromazine in liquid form, 100 mg. every 8 hours for 5 to 6 weeks. Testing was carried out on Days 4,8,15,22,29, and 36 or 43 of treatment: (1) Blood samples were taken for chlorpromazine assessment at 0, 2, 4, and 6 hours after the morning dose; (2) blood pressure and pulse rate, pupil size, sweat gland activity, and electroencephalogram (EEG) were recorded at these times; (3) salivary secretion, EEG-evoked response, auditory reaction time, and handwriting tests were carried out at the 2 hour point; and (4) clinical ratings were made between 2 and 4 hours. Wide interpatient variation in plasma level was found; concentrations were maximal in the first 2 weeks, then consistently declined. Changes in the peripheral autonomic measures correlated with those in plasma level, but changes in the central measures were inconsistent. Plasma levels and clinical improvement were weakly related during the first 2 weeks of treatment only. Clinical improvement correlated with palmar skin conductance (sweating) and with some latencies of the electroencephalographic-evoked response. The determination of chlorpromazine plasma levels should be of use in investigating nonresponders and patients with severe autonomic effects.

No abstract