Initial treatment choices, second-line therapy, and reasons for stopping medication in the treatment of hypertension by general practitioners in England, Scotland and Wales: 1990-1995.

Information on general practitioners' choices of initial and second-line antihypertensive treatment, and reasons for stopping therapy, are limited. We analysed data on the use of the four main classes of antihypertensive drugs (diuretics, beta-blockers, calcium antagonists and angiotensin-converting enzyme inhibitors) between 1990 and 1995 from an ongoing cross-sectional postal survey of general practitioners' prescribing activity (the New and Change Therapy Enquiry). There were 18,092 new courses and 9424 discontinuations between 1990 and 1995. Diuretics were the commonest first-line choice. Use of beta-blockers first-line decreased significantly in comparison with diuretics during the study period. Switches to calcium antagonists and angiotensin-converting enzyme inhibitors increased. The increased use of newer agents was not explained by increased use for concomitant conditions (diabetes or cardiovascular disease). Diuretics were most often discontinued because of poor efficacy (44% of diuretic stops). In contrast, most beta-blockers (55%), calcium antagonists (64%) and angiotensin-converting enzyme inhibitors (60%) were stopped because of side-effects. In conclusion, use of beta-blockers first-line decreased. Switches to calcium antagonists and angiotensin-converting enzyme inhibitors increased. The reasons may be due to greater perceived efficacy of newer agents rather than increased use for concomitant conditions.