Some of the views expressed in the following notes on newly approved products should be regarded as preliminary, as there may have been limited published data at the time of publication, and little experience in Australia of their safety or efficacy. However, the Editorial Executive Committee believes that comments made in good faith at an early stage may still be of value. Before new drugs are prescribed, the Committee believes it is important that more detailed information is obtained from the manufacturer's approved product information, a drug information centre or some other appropriate source.
Bicor (Alphapharm)
1.25 mg, 2.5 mg, 5 mg and 10 mg tablets
Approved indication: heart failure
Australian Medicines Handbook Section 6.4.3
Some patients with heart failure will benefit from the addition of a beta blocker to their other treatments (see 'Beta blockers in heart failure' Aust Prescr 2000;23:120-3). Bisoprolol is one of the beta blockers which can be used in patients with stable, chronic, moderate to severe heart failure.
The drug is selective for beta-1 receptors. This selectivity is reduced at higher doses so the lowest effective dose should be used. Bisoprolol is lipophilic and hydrophilic. It has no intrinsic sympathomimetic activity.
First-pass metabolism reduces the bioavailability of bisoprolol to 80%. As half the dose is excreted unchanged in the urine and half is metabolised, lower doses should be used in patients with renal or hepatic impairment. The half-life of bisoprolol is normally 9-12 hours.
In the first Cardiac Insufficiency Bisoprolol Study (CIBIS) there was no significant difference in patient mortality between bisoprolol and placebo.1 The second study (CIBIS II) enrolled more patients.2 After an average of 1.3 years of treatment 228 (17%) of the 1320 patients given a placebo were dead compared with 156 (12%) of the 1327 patients given bisoprolol. A significant fall in sudden deaths suggests that the benefits of bisoprolol may be related to an antiarrhythmic action. Bisoprolol also resulted in significantly fewer admissions to hospital for deteriorating heart failure. The effects of bisoprolol were greatest in patients who had ischaemic heart disease and (New York Heart Association) class III heart failure.
It is important to begin with a low dose of bisoprolol and monitor patients closely as some patients' heart failure will get worse. The adverse reactions include bradycardia, hypotension and other effects typical of beta blockers.
In clinical trials, carvedilol and metoprolol have also reduced mortality when added to conventional treatment. There is no evidence to say which beta blocker is the most effective.
