Use and cost of branded and generic drugs in patients with coronary heart disease--results from a prospective survey of 1008 patients in two London hospitals.

Background: Combination therapy with three classes of drug, antiplatelet, cholesterol and blood pressure lowering treatment markedly reduce the risk of recurrent cardiovascular events in patients with coronary heart disease (CHD). Within each class, generic and branded (patented) drugs are available which have similar efficacy but differ in cost.

Aims: (i) To assess the extent to which preventive medical drugs are prescribed in patients with CHD and to examine the reasons for drug omissions and (ii) to assess the relative use of branded and generic drugs and the reasons for drug selection.

Methods: The medication charts and hospital notes of consecutive patients undergoing percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) at a large cardiothoracic centre were reviewed over a 3-month period. Interviews with patients, attending cardiologists and general practitioners were undertaken to establish why drugs were and were not prescribed.

Results: Among 1008 patients (755 who had PCI and 253 who had CABG) the use of aspirin, statins, angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARB), beta blockers and calcium channel blockers were, respectively, 97, 98, 81, 76 and 18%. The combination of any 4 classes of drug were used in 65% of patients. Almost all patients who did not receive aspirin or a statin had clinical contraindications and were on alternative drugs. In about 12% of patients without an ACE inhibitor (or ARB) and 7% of patients without a beta blocker, no reason to withhold such treatment was identified. Branded drugs were used in 52% of patients; the most commonly prescribed being atorvastatin in 33%. Clinical reasons for using branded rather than generic drugs were identified in 13% of cases.

Conclusion: Our results show a high rate of use of secondary preventive cardiac medications in patients undergoing coronary revascularization procedures, but the use of ACE inhibitors or beta blockers is still overlooked in about 1 in 10 patients. Branded drugs are prescribed in about half of all patients undergoing PCI and CABG, but in almost 90% of cases, a generic equivalent could have been used to achieve similar risk reduction. If our results reflect wider practice, an estimated 11 million pounds a year would be saved by the National Health Service by switching to generic alternative drugs.