Effectiveness of blood pressure control with once daily administration of enalapril and perindopril

Efficacy of perindopril in the treatment of systemic hypertension

The angiotensin-converting enzyme inhibitor, perindopril erbumine, has been approved for use in the United States only recently but has been studied extensively worldwide over the last decade. Placebo-controlled trials in a wide range of patients with hypertension, including the elderly, those with isolated systolic hypertension, and those with concomitant diseases such as hyperlipidemia, diabetes, cardiac arrhythmia, peripheral arterial occlusive disease, nephropathy with proteinuria, and chronic obstructive pulmonary disease, have shown that perindopril is highly effective in lowering both systolic and diastolic blood pressure (BP). Studies in which BP has been monitored for 24-hour intervals show that perindopril (1) has a gradual onset of action, (2) provides smooth BP control over its once-daily dosing interval, (3) has a trough-peak ratio of about 1, and (4) maintains its antihypertensive efficacy despite missed doses. Perindopril increases arterial compliance and reverses left ventricular hypertrophy in hypertensive patients. Both of these effects are at least partly independent of its ability to lower BP. Perindopril is safe and well tolerated in patients with hypertension. Rates of adverse events and discontinuation because of such events are low.

Dosage considerations with perindopril for systemic hypertension

Perindopril erbumine is a once-daily angiotensin-converting enzyme (ACE) inhibitor that effectively lowers systolic and diastolic blood pressure (BP) in patients with mild-to-moderate hypertension. Converted from the prodrug ester perindopril, the active diacid perindoprilat is distributed rapidly and extensively, primarily to tissues with high ACE activity. Its ability to lower BP is comparable to or better than that of other antihypertensive agents, both of its own class and other classes, and its trough-peak ratio is consistently between 75% and 100%, translating into 24 hours of true efficacy per dose. First-dose hypotension caused by an initial acute BP depression occurs less frequently with perindopril than with other ACE inhibitors, an advantage in volume-contracted patients and those whose BP is angiotensin II dependent, such as patients with congestive heart failure. A missed-dose study showed that most of the antihypertensive effect of perindopril remains for 24 to 48 hours after dosing, a characteristic that confers protection to patients who miss a dose. Perindopril improves the distensibility and compliance of large and small arteries, which are compromised in hypertension, and can effect vascular remodeling by a mechanism independent of BP lowering. The clinical implications of these effects are being investigated in large trials. Perindopril is well tolerated in the elderly, and combination therapy with a diuretic was shown to yield significant additional BP reduction. Perindoprilat is cleared renally; dosage should be adjusted in patients with renal impairment.

In vivo activation of rat aortic platelet-derived growth factor and epidermal growth factor receptors by angiotensin II and hypertension

It is unclear whether the previous in vitro evidence of a link between angiotensin II (Ang II) and growth factor receptors can apply to the in vivo situation. In this study, we examined vascular platelet-derived growth factor (PDGF) and epidermal growth factor (EGF) receptor activation in stroke-prone spontaneously hypertensive rats (SHRSP) and the role of Ang II. Tyrosyl phosphorylation of the growth factor receptors was determined by Western blot analysis coupled with immunoprecipitation. Tyrosyl phosphorylation of the aortic PDGF beta-receptor, but not the EGF receptor, was chronically increased in SHRSP with hypertension, compared with normotensive rats, being accompanied by increased extracellular signal-regulated kinase (ERK) activity. Treatment of SHRSP with ACE inhibitors (perindopril or enalapril) significantly reduced aortic PDGF beta-receptor tyrosyl phosphorylation and ERK activity, whereas treatment with hydralazine failed to reduce these activities. Therefore, these aortic changes in SHRSP were mediated by Ang II in response to vascular ACE. Ang II was infused into rats to examine the effects on aortic growth factor receptors. Chronic Ang II infusion, via the angiotensin type 1 receptor, significantly increased activation of the aortic PDGF beta-receptor but not the EGF receptor. Thus, the aortic PDGF beta-receptor, activated by ACE-mediated Ang II, seems to be responsible for vascular remodeling in hypertensive rats.

The effect on 24 h blood pressure control of an angiotensin converting enzyme inhibitor (perindopril) administered in the morning or at night

OBJECTIVE

To determine the clinic and ambulatory blood pressure when the same dose of perindopril (4 mg) is administered in the morning (0900 h), or at night (2100 h), in particular, to determine whether the early morning blood pressure rise, the duration of effect and the pattern of response differed.

METHODS

Twenty male patients with diastolic blood pressure 95-110 mmHg when seated and 24 h mean ambulatory diastolic blood pressure > 85 mmHg after 4 weeks' placebo were allocated randomly to be administered 4 mg perindopril at 0900 h or at 2100 h. Clinic blood pressure (with the patient seated and erect) was measured 2 and 4 weeks after the therapy had been started and ambulatory blood pressure monitoring with a SpaceLabs device was performed for 26 h during week 4. The patients then crossed over to the other time of dosage and the measurements were repeated. The study was conducted from a hospital clinic.

RESULTS

The clinic analysis concerned all 20 patients but the ambulatory analysis concerned 18 patients because the ambulatory blood pressure monitor data sets were inadequate for two patients. Compliance was high (97 +/- 3%), with a suggestion that it was better with the 0900 h dose. Clinic blood pressure (with the patient seated and erect) was lower under both regimes and the blood pressure with night-time administration of perindopril tended to be lower than that with daytime administration (P = 0.05-0.10). Twenty-four-hour mean, daytime and night-time means were lower with both doses than they were with placebo and did not differ. Both regimes reduced the early morning peak blood pressure rise and the effect tended to be greater with the 2100 h dose (P = 0.05-0.10). The 0900 h dose had an effect that persisted for > 24 h but the effect of the 2100 h dose had dissipated 18 h after the dose. There was no excessive night-time fall in blood pressure with the 2100 h dose. The trough : peak ratio with the 0900 h dose was 0.86 for systolic and 0.70 for diastolic blood pressure.

CONCLUSION

The early morning blood pressure rise is reduced more when 4 mg perindopril is administered at 2100 h. However, the 2100 h dose regime does not reduce blood pressure over 24 h whereas 24 h control is achieved with the 0900 h dose. In clinical practice the 2100 h dose would have been titrated to the next dose range in more patients. This study indicates that the response profile obtained with an angiotensin converting enzyme inhibitor cannot be transformed from one dose time to another automatically and that chronobiology has important effects on a drug's action.