The Role of a Slow Channel Inhibitor, Verapamil, in the Management of Hypertension

Summary 1 The ‘Oxford’ system for continuous monitoring of the ambulatory blood pressure was used to assess the changes in blood pressure following therapy with the slow channel inhibitor, verapamil. 2 Sixteen patients were studied on no therapy and following a minimum of 6 weeks therapy (dose range 120–160 mg t.d.s.). During each study patients underwent standardized physiological tests including tilt, isometric handgrip and dynamic bicycle exercise. 3 Verapamil was demonstrated to produce a consistent reduction of blood pressure over most of the 24 h period studied but this was most marked during the day. Heart rate was also reduced. 4 There was no postural hypotension and the absolute responses to dynamic and isometric exercise were reduced. 5 The results demonstrate the antihypertensive efficacy of ‘slow channel inhibitors’ as represented by verapamil.