Imidapril hydrochloride in essential hypertension: a double-blind comparative study using enalapril maleate as a control.
OBJECTIVE
To assess the value of using imidapril hydrochloride (ACE/TA-6366), a long-acting angiotensin converting enzyme (ACE) inhibitor developed in Japan, to treat patients with essential hypertension.


METHODS
A double-blind, comparative, phase III study was carried out using enalapril maleate as a control, with a 4-week observation period and a 12-week treatment period. Both drugs were started at a dose of 5 mg once a day, increasing to 10 mg in patients whose antihypertensive response was insufficient after 4 weeks. The study included 231 outpatients aged 30-74 years; of these, 108 in the imidapril group and 115 in the enalapril group were assessed. There were no differences in background factors between groups.


RESULTS
An adequate antihypertensive effect was observed in 71.3% (77/108) in the imidapril group in in 66.1% (76/115) in the enalapril group, with no significant difference between groups. The pulse rate was unchanged in both groups. The drug had no adverse effects in 86.1% (93/108) of the imidapril group and 79.1% (91/115) of the enalapril group, with no significant difference between groups. Adverse drug effects were observed din 5.6% (6/108) of the imidapril group and 12.2% (14/115) of the enalapril group. Cough was the most frequent side effect, reported in 0.9% (1/108) of the imidapril group and 7.0% (8/115) of the enalapril group. Other side effects were reported in 4.6% (5/108) of the imidapril group and 5.2% (6/115) of the enalapril group. Abnormal laboratory values were observed in 3.7% (4/108) of the imidapril group and 0.9% (1/115) of the enalapril group.


CONCLUSIONS
Imidapril showed excellent clinical efficacy and safety compared to enalapril. The low incidence of cough is of particular interest.
Saruta
T
T
Department of Internal Medicine, Keio University, Tokyo, Japan.
Omae
T
T
Kuramochi
M
M
Iimura
O
O
Yoshinaga
K
K
Abe
K
K
Ishii
M
M
Watanabe
T
T
Takeda
T
T
Ito
K
K
D000328:Adult; D000368:Aged; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D004311:Double-Blind Method; D004656:Enalapril / Q000627:therapeutic use; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D007093:Imidazoles / Q000627:therapeutic use*; D048289:Imidazolidines; D008297:Male; D008875:Middle Aged
D000806:Angiotensin-Converting Enzyme Inhibitors; D007093:Imidazoles; D048289:Imidazolidines; D004656:Enalapril; C065166:imidapril