Clinical significance of plasma drug and prolactin levels during acute chlorpromazine treatment: a replication study.

Nineteen patients with acute psychoses, the majority schizophrenics, were studied in the course of chlorpromazine (CPZ) treatment. Plasma levels of the drug, plasma prolactin (PRL), extrapyramidal side-effects (EPS) and changes in mental state were monitored weekly, as in our earlier study. The results confirm some of our previous findings: (a) plasma CPZ levels vary widely among patients and correlate poorly with daily doses of CPZ; (b) increased plasma PRL is associated with higher plasma CPZ levels and is more common among the patients who develop EPS; and (c) none of these three variables differ between groups of patients with good and poor treatment outcome. However we did not confirm our previous finding of a significant association between EPS and higher plasma CPZ, nor did we find that the ratio of CPZ-sulphoxide to CPZ differed between the improved patients and the rest.