spirapril and Hypotension

The purpose of this double-blind, randomised trial with a 4-week placebo run-in period followed by an active treatment period using either spirapril 3 mg or 6 mg once a day was to clarify the existence of hypotensive episodes in elderly hypertensive patients treated by an ACE-inhibitor. Forty hypertensive patients aged 60-76 years underwent 24-h ABPM at the end of the run-in (week 4) and active treatment (week 9) periods. The mean 24-h systolic blood pressure (SBP) decreased from 161.9 (26.7) mm Hg to 150.6 (29.9) mm Hg (P < 0.001) and diastolic blood pressure (DBP) from 91.70 (14.7) mm Hg to 84.2 (17.3) mm Hg (P < 0.001). No episodes of mean arterial pressure (MAP) <50 mm Hg were seen during the placebo period. Instead 11 episodes were observed during the antihypertensive treatment (one in the 3 mg group and 10 in the 6 mg group, P < 0.01 between the two treatment groups). Fifty-four episodes of MAP <70 mm Hg were observed during the placebo period and 117 during the treatment period (P < 0.001). During the placebo period low MAPs were observed only during night time. During the treatment period they were seen also from 11 am to 4 pm. In conclusion, ACE-inhibitor therapy with spirapril significantly increased hypotensive episodes in elderly hypertensive patients which may worsen their cerebral and myocardial circulation.

Topics: Aged; Analysis of Variance; Angiotensin-Converting Enzyme Inhibitors; Blood Pressure Monitoring, Ambulatory; Chi-Square Distribution; Circadian Rhythm; Dose-Response Relationship, Drug; Double-Blind Method; Drug Administration Schedule; Enalapril; Female; Follow-Up Studies; Humans; Hypertension; Hypotension; Male; Middle Aged; Prevalence; Reference Values; Risk Assessment; Severity of Illness Index; Treatment Outcome

The administration of most angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) at bedtime results in a greater reduction of nighttime blood pressure (BP) than dosing upon awakening. It has been proposed that this effect may be a consequence of a short half-life and duration of action. However, those findings were also documented for long-acting medications, such as the ARB telmisartan. Accordingly, we investigated the administration-time-dependent effects on ambulatory BP of spirapril, an ACEI with an elimination half-life of about 40 h. We studied 165 previously untreated hypertensive subjects, 42.5 +/- 13.9 yrs of age, treated with spirapril (6 mg/day) as monotherapy for 12 weeks either upon awakening or at bedtime. BP was measured by ambulatory monitoring for 48 h before and after treatment. The BP reduction during diurnal activity was similar for both treatment times. Bedtime spirapril administration, however, was significantly more efficient than morning administration in reducing asleep BP. The awake/asleep BP ratio was decreased with the upon-awakening spirapril treatment schedule but significantly increased toward a more dipping pattern with the bedtime treatment schedule. The proportion of patients with controlled ambulatory BP increased from 23 to 59% (p < 0.001) with bedtime treatment. Sleep-time BP regulation is significantly better achieved with bedtime spirapril administration. This might be clinically important, as the sleep-time BP mean has been shown to be a more relevant marker of cardiovascular risk than the awake mean values. These administration-time-dependent effects of spirapril seem to be a class-related feature, and may be associated with the nocturnal activation of the renin-angiotensin-aldosterone system.

Topics: Adult; Angiotensin-Converting Enzyme Inhibitors; Antihypertensive Agents; Benzimidazoles; Benzoates; Blood Pressure; Blood Pressure Monitoring, Ambulatory; Cardiovascular Diseases; Enalapril; Female; Half-Life; Humans; Hypertension; Hypotension; Male; Middle Aged; Receptors, Angiotensin; Renin-Angiotensin System; Risk; Telmisartan