Cilazapril monohydrate

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.

Inhibace (Bayer Australia)
1 mg, 2.5 mg and 5 mg tablets

Indication: hypertension
This is another angiotensin converting enzyme (ACE) inhibitor which will be competing in the antihypertensive drug market; a market worth over $250 million in 1992/93.

Cilazapril is a prodrug which is converted to active cilazaprilat. The half-life of cilazaprilat is approximately 9 hours and it is excreted unchanged by the kidneys. Some patients may need a twice daily dose to control their blood pressure for 24 hours. Reduced doses are recommended for the elderly and patients with renal impairment.

A quality of life study compared cilazapril, atenolol and nifedipine in patients with mild to moderate essential hypertension. After6 months' therapy, all 3 drugs had reduced diastolic blood pressure, but significantly more

patients taking cilazapril needed to have a diuretic added to their treatment. Atenolol and cilazapril had similar effects on the quality of life.1

Treatment begins at a low dose for the first two days and with the same precautions as for other ACE inhibitors. The adverse effects are also similar and include headache, dizziness and cough. Neutropenia, which can also occur in patients taking captopril, has been reported.

Cilazapril has only been approved for the treatment of mild to moderate hypertension. It has no apparent advantages over its competitors.


  1. Fletcher AE, Bulpitt CJ, Chase DM, Collins WC, Furberg CD, Goggin TK, et al. Quality of life with three antihypertensive treatments: cilazapril, atenolol, nifedipine. Hypertension 1992;19:499-507.