Evaluation of the Relative Incidence of Adverse Effects Leading to Treatment Discontinuation of Recommended Antihypertensive Drugs

This study aimed at evaluating the incidence of adverse effects leading to treatment discontinuation of antihypertensive drugs within the same therapeutic class. Individual medical records were searched to identify those hypertensive patients who had been commenced on antihypertensive therapy during a 24month period and who had subsequently for a reason(s) discontinued the therapy. The results showed variation in discontinuation rates for drugs within same class, and that might be related to the relative frequency of specific adverse effects. Cough was the reason cited for discontinuation of angiotensin converting enzyme inhibitors, with linosopril appearing to be better tolerated than captopril (39% vs 48%) ; peripheral oedema with calcium channel blockers, with amlodipine appearing to be better tolerated than nifedipine (29% vs 38%) and bradycardia with beta adrenergic receptor blockers, with propranolol better tolerated than atenolol (0% vs 48%). Diuretics showed the lowest discontinuation rate (3.3%) mainly due to hypokalemia, with thiazide better tolerated than frusemide (11% vs 43%). Prescribers should verify their use of antihypertensive drugs to ensure that they prescribe drugs with lower adverse effect rates, in order that patients with hypertension continue using the medication in the long term, thereby reducing the risk of developing cardiovascular complications associated with uncontrolled blood pressure.