1 The pharmacokinetics of enalaprilat were studied after administration of single and multiple doses of enalapril maleate to people with normal and impaired renal function. 2 Renal impairment was associated with higher serum concentrations of enalaprilat, longer times to peak concentrations, slower decline of serum concentrations and with reduced urinary elimination. Urinary elimination of enalaprilat was closely related to renal function.3 In patients with severe renal impairment (GFR values below 30 ml min7l 1.73 m-2) significantly smaller doses of enalapril maleate will be required than in patients with normal or less severely impaired renal function.

SUMMARY Baroreflex function was assessed in elderly hypertensive patients and compared with that observed in young hypertensives and young normotensives. Mean arterial pressure was reduced by 20% using intravenous nitroprusside infusion in 10 elderly hypertensive patients (older than 65 years and diastolic pressures over 95 mm Hg), in 10 young hypertensives (under 60 years and diastolic pressures over 95 mm Hg), and in seven young normotensive subjects (under 60 years and diastolic pressures under 95 mm Hg). Elderly subjects demonstrated greater sensitivity (p < 0.005) and greater variability of response (p < 0.025) to nitroprusside than either young group. There was no significant difference between the slight heart rate increases observed in the supine position in the three groups. However, in the erect position, heart rate increases were significantly less in the elderly hypertensive group than in the young hypertensive group (p < 0.01) or the young normotensive group (p < 0.005). Furthermore, the slope of the regression line relating change in blood pressure with change in R-R interval was less for the elderly patients than for the young hypertensives (p < 0.05) or the young normotensives (p < 0.025). We conclude that the heart rate component of the baroreflex is impaired in elderly hypertensives, and anticipate that the clinical response to antihypertensive drugs will be altered. (Hypertension 5: 763-766, 1983) KEY WORDS * nitroprusside * heart rate • aging A GING is associated with alteration in many physiological systems that can respond to drugs. 1 Previous workers have shown altered response in the cardiovascular system to various pharmacological agents.2 " 3 Baroreflex activity, which is important in cardiovascular homeostasis, has been shown to decline with increasing arterial pressure 67 and with increasing age up to 66 years. 8 However, no information is available in older hypertensive patients. Since impaired baroreflex function in such patients would have important therapeutic implications, we assessed some aspects of the baroreflex by studying blood pressure and heart rate response to nitroprusside in a group of such patients, and comparing the results with those observed in young hypertensives and young normotensives. Methods and MaterialsThree groups of patients were studied -elderly hypertensives, young hypertensives, and young normotensives. The elderly hypertensives were all older than 65 years, with ages ranging from 66 to 80 years. Diastolic pressures were greater than 95 mm Hg in each case. The supine mean arterial pressure (diastolic pressure + Vi pulse pressure) ranged from 115 to 154 mm Hg, and the erect mean arterial pressure ranged from 113 to 160 mm Hg. The mean baseline supine heart rate was 74.9 ± 2.9 beats min~' and the mean erect heart rate was 77.3 ± 2.9 beats min." 1 . The young hypertensives were under 60 years of age -ranging from 32 to 56 years. Their diastolic pressures were greater than 95 mm Hg, with supine mean arterial pressures ranging from 114 to 135 mm Hg and ...

No abstract

No abstract

No abstract