Headache is the commonest and often the only symptom of hypertensive disease. It occurs in about 50% of patients. The distress it causes is sometimes unbearable, and the common analgesics are frequently ineffective in its relief.
Thiocyanate has long been used in the symptomatic treatment of hypertension. Because of its severe toxic effects at high serum concentration, however, periodically it lapsed into disuse until Barker1 introduced as a safeguard the technique of routine measurement of serum thiocyanate concentration. He noted relief of headache in 76% of his patients; similar incidences (from 50 to 88%) of relief have been observed by others (Kurtz, Shapiro and Mills,2 Fanson, Kinsey and Palmer,3 Blumenthal and Wetherby,4 Watkinson and Evans,5 Alstad,6 Fischman and Fischmann,7 Aas and Thingstad,8 and Thomas9). Hypertensive headache is now recognized (Page and Corcoran10) as the major indication for treatment with thiocyanate.