title: Cough-challenge trial with a new angiotensin-converting enzyme inhibitor, imidapril.
abstract: This study was conducted to examine whether imidaprilat, an active diacid of the angiotensin-converting enzyme (ACE) inhibitor imidapril, preferentially inhibits angiotensin I degradation rather than bradykinin degradation, and whether imidapril is less active than other ACE inhibitors in inducing cough in patients with hypertension. The effect of imidaprilat on the inhibition of pressor response to angiotensin I and augmentation of depressor response to bradykinin was compared with that of enalaprilat and captopril in anesthetized rats. To determine the incidence of cough associated with imidapril, patients with a history of ACE inhibitor-induced dry cough were enrolled in a randomized, open-labeled, crossover trial with two 6-week periods to be treated with imidapril or amlodipine, a calcium-channel blocker. The recurrence of cough was assessed during both treatments. In the animal study, there were no significant differences in the ratio of inhibition of pressor response to angiotensin I and the augmentation of depressor response to bradykinin among the ACE inhibitors. In the cough-challenge trial, a total of 60 patients with hypertension were enrolled in the study. Cough and cough related symptoms recurred in 98.3% of the patients (59/ 60) during imidapril therapy. In contrast, only two patients reported cough during treatment with amlodipine. These results indicate that imidapril has no selectivity in inhibiting angiotensin I- and bradykinin-degradation in rats, and that clinically it is not different from other ACE inhibitors in inducing cough in patients with hypertension.
authors.affiliation: Second Department of Internal Medicine, Yokohama City University School of Medicine, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Shionoiri
authors.forename: I
authors.initials: I
authors.lastname: Takasaki
authors.forename: K
authors.initials: K
authors.lastname: Minamisawa
authors.forename: S
authors.initials: S
authors.lastname: Ueda
authors.forename: M
authors.initials: M
authors.lastname: Kihara
authors.forename: K
authors.initials: K
authors.lastname: Shindo
authors.forename: S
authors.initials: S
authors.lastname: Hiroto
authors.forename: K
authors.initials: K
authors.lastname: Sugimoto
authors.forename: H
authors.initials: H
authors.lastname: Himeno
authors.forename: M
authors.initials: M
authors.lastname: Naruse
authors.forename: I
authors.initials: I
authors.lastname: Nagamochi
authors.forename: G
authors.initials: G
authors.lastname: Yasuda
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001920:Bradykinin / Q000187:drug effects / Q000378:metabolism; D003371:Cough / Q000139:chemically induced*; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D007093:Imidazoles / Q000009:adverse effects / Q000627:therapeutic use*; D048289:Imidazolidines; D008297:Male; D008875:Middle Aged; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D007093:Imidazoles; D048289:Imidazolidines; C065166:imidapril; D001920:Bradykinin