Eprosartan mesylate

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.

Teveten (SmithKline Beecham)
300 mg and 400 mg tablets
Approved indication: hypertension
Australian Medicines Handbook Section 6.4.5

Eprosartan is another one of the recently approved angiotensin1 receptor antagonists (see 'Angiotensin receptor antagonists for the treatment of hypertension' Aust Prescr 1998;21:95-7). As this class expands, there is clearly a need for comparative studies. In the meantime, the precise role of the class in the treatment of hypertension remains unclear. While the drugs do have a low short term incidence of adverse effects, there is little knowledge about their long-term effect on outcomes, either adverse or beneficial.

The absorption of eprosartan is reduced by food, but this is considered to be clinically inconsequential. Absolute bioavailability is 13%. Eprosartan is partly metabolised and excreted in the bile and urine. Its pharmacokinetics are affected by severe liver or kidney disease. Lower starting doses are recommended in the elderly and patients with sodium/volume depletion. The half-life is 5-9 hours, but the manufacturer recommends only once daily dosing. If a patient is not responding, consideration can be given to changing to twice daily dosing before increasing the total daily dose.

Clinical trials show that eprosartan reduces diastolic blood pressure by 2-5 mmHg more than placebo. Studies comparing eprosartan and enalapril show that they are equally effective at lowering diastolic blood pressure. In one study, eprosartan had an effect on systolic blood pressure which was statistically greater than the effect of enalapril.

Like other members of this class, eprosartan has a low risk of adverse reactions. In placebo-controlled trials, 4% of patients taking eprosartan dropped out because of adverse events compared with 6.5% of the placebo group. The incidence of cough is lower than with ACE inhibitors.