Queen Mary Utilization of Antihypertensive Drugs Study: use of antihypertensive drug classes in the hypertension clinic 1996-2004.

Background: Utilization of antihypertensive drugs in the hypertension outpatient clinic is surveyed periodically in the Queen Mary Utilization of Antihypertensive Drugs Study (QUADS).

Methods: Two hundred and fifty-one patients (123 men, 128 women) were interviewed in April to December 1996, 439 patients (232 men, 207 women) in January to December 99 and 228 patients (109 men, 119 women) in April to May 2004. Their case notes were reviewed.

Results: The percentages of patients receiving no drug (lifestyle modification), one, two, three and over three drugs were 7%, 48%, 36%, 7%, 3%, respectively, in 1996; 14%, 34%, 36%, 13% and 1%, respectively, in 1999; and 3%, 30%, 40%, 22% and 6%, respectively, in 2004. The number of drugs correlated with age and overweight. In 1996, 51% patients received calcium channel blockers (CCB); 46% beta-blockers (BB); 32% angiotensin-converting enzyme inhibitors (ACEI); 15% thiazide diuretics; 5% alpha-blockers; and 0% angiotensin receptor blockers (ARB). In 1999, the respective figures were 52% CCB, 49% BB, 24% ACEI, 22% thiazide diuretics, 4%alpha-blockers and 2% ARB. In 2004, the respective figures were 65% CCB, 64% BB, 33% ACEI, 24% thiazide diuretics, 4% alpha-blockers and 7% ARB. Fewer patients on BBs reported side-effects. Only 11% were on alpha statin and 9% on aspirin. Blood pressure on treatment was 147 +/- 21/84 +/- 11 mmHg in 1999 and 144 +/- 21/82 +/- 11 mmHg in 2004.

Conclusions: Increasingly, multiple drugs were used for blood pressure control. Blood pressure control needs improvement, especially in diabetics. CCBs and BBs were consistently popular. Thiazide diuretics, ARBs, statins and aspirin were underused, despite favourable clinical trial evidence.