Evaluation of amlodipine, lisinopril, and a combination in the treatment of essential hypertension

Angiotensin converting enzyme (ACE) inhibitors and dihydropyridine calcium antagonists are well established and widely used as monotherapy in patients with mild to moderate essential hypertension. Earlier studies combining sh ort acting drugs from these classes require multiple dosing and were associ ated with poor compliance. Availability of longer acting compounds allows o nce daily administration to avoid the inconvenience of a multiple daily dos e. It was decided to perform a randomised double blind. crossover study wit h the long acting calcium channel blocker amlodipine and the long acting AC E inhibitor lisinopril, given either alone or in combination in essential h ypertension. Twenty four patients with diastolic blood pressure (DBP) betwe en 95 and 104 mm Hg received amlodipine 2.5 mg and 5 mg, lisinopril 5 mg an d 10 mg, and their combination as per a prior randomisation schedule. Supin e and standing blood pressure and heart rate were recorded at weekly interv als. Higher doses of both the drugs individually or in combination were use d if the target supine DBP below 90 mm Hg was not achieved. There was a sig nificant additional blood pressure lowering effect with the combination whe n compared either with amlodipine or lisinopril alone. Five mg amlodipine a nd 10 mg lisinopril monotherapy achieved the target blood pressure in 71% a nd 72% patients respectively. The combination of 2.5 mg amlodipine with 5 m g Lisinopril produced a much more significant lowering of blood pressure in a higher percentage of patients than that with an individual low dose.