Development of extrapyramidal symptoms in hypertensive patients treated with diazoxide.

Extrapyramidal symptoms developed a variable time after the start of treatment with oral diazoxide in 15% of a series of 100 severely hypertensive patients. Six illustrative cases are described. Treatment with diazoxide could be continued in four of these. The symptoms are usually controllable either by dosage adjustment or by the use of diazepam or procyclidine. There was no evidence of irreversibility of the extrapyramidal syndromes observed.