Queen Mary Utilization of Antihypertensive Drugs Study: Side-effects of antihypertensive drugs

Background and objective: Effective prevention of cardiovascular events in hypertensive patients requires good control of blood pressure. Side-effects of antihypertensive drugs affect tolerability and compliance. Accordingly, we surveyed side-effects in the hypertension outpatient clinic. Methods: A total of 228 patients (109 men, 119 women) were interviewed in April-May 2004 in the Queen Mary Utilization of Antihypertensive Drugs Study. Results: The percentage of patients receiving no drug (life-style modification), one, two, three and over three drugs were 3, 30, 40, 22 and 6% respectively. The proportion of patients taking calcium channel blockers, beta-blockers (BB), angiotensin-converting enzyme inhibitors, thiazide diuretics, alpha-blockers and angiotensin receptor blockers were 65, 64, 33, 24, 4 and 7% respectively. Blood pressure on treatment was 144 +/- 21/82 +/- 11 mmHg. Among patients on antihypertensive drug therapy, 34% reported adverse effects: dizziness (9%), ankle swelling (7%), headache (5%), fatigue (4%), chest discomfort (3%) and cough (3%). Fewer patients on BBs reported side-effects (OR 0.46, P = 0.008). The likelihood of experiencing side-effects was unrelated to sex, age, weight, BMI, years of treatment, number of drugs used, heart rate on treatment or compliance. Conclusions: To achieve good blood pressure control, multiple drugs are used. Thiazides are underused whereas BBs are popular. The popularity of the latter may be related to its tolerability.