Stopping drug treatment of hypertension: experience in 18 British general practices.

Background: Of the many reports published describing the effect of withdrawing antihypertensive medication from patients who have well-controlled blood pressure, none have been major British general practice studies. Studies from other settings have shown that a substantial minority can do so without harm or resulting in the relapse of their hypertension.

Aim: To determine the proportion of hypertensive patients who could have their medication withdrawn without relapse, and to seek factors associated with success at withdrawal.

Method: A longitudinal observational study in 18 general practices in north-east England. Practices selected and managed patients to guidelines suggested by the study protocol. Data were abstracted from records by practice staff over three years of follow-up.

Results: A total of 196 out of 224 (88%) patients were followed up. Forty-three (22%) of these 196 remained normotensive off medication for the whole study. A total of 108 (55%) of the 196 had restarted medication by three months. Twenty-six (31%) of the 84 males, but only 17 (15%) of the 112 females, remained off medication. No differences in age, morbidity, symptoms, or biochemical parameters occurred between the group who stayed off medication and those who restarted it. Apart from male sex, no factors were found that enabled the prediction of patients more likely to succeed at stopping medication.

Conclusions: One-fifth of well-controlled hypertensives in British primary health care could have their medication withdrawn without the relapse of their hypertension or any harm. Of those that do relapse, over half are likely to have done so before three months. Life-long observation of all patients is essential.