Sensitivity to a Phenothiazine (Butaperazine)

Abstract

A second study of butaperazine on twenty-two patients compared to a previous group of twenty-four patients revealed rather similar results. Twenty of the subjects were involved in both studies, with an eleven-week period off medication in between the two treatment regimes. In the first study matched groups received different dose levels, there being no physician's choice of treatment. In the second study twenty of the same patients were subjected to treatment with the same drug, according to a six-week scheme, which was laid down beforehand and then followed by a six-week treatment at the doctor's discretion. Despite marked differences in the dose levels between the two studies, no great differences in improvement were shown with, if anything, improvement being greater in the first study. There was a marked increase in acute dystonic reactions in the patients who received large amounts of starting medication, but no great difference in the amount of extra-pyramidal system disturbance. However, in the second study it was noted that extrapyramidal disturbance appeared earlier, at a lower dose level, was more difficult to control and, indeed, was felt to interfere with behavioural improvement. A hypothesis that sensitization to butaperazine occurred was put forth to explain the discrepancy and was supported by the introduction of a formula for an index of sensitivity.