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Biomedical subjects

K H Rahn

Publications and source records attributed to K H Rahn.

233 records · Page 13Linked to original sources
PubMedDate not supplied

Time course of blood pressure changes after intravenous administration of propranolol or furosemide in hypertensive patients.

The time course of changes in supine and standing blood pressures, heart rate, plasma renin activity, and plasma noradrenaline concentration after intravenous administration of propranolol (0.20 mg . kg-1, with a maximum of 15 mg) or furosemide (40 mg) was studied for a period of 8 h in hypertensive patients. Twenty minutes after intravenous injection of propranolol or furosemide, supine blood pressure was unchanged. Thereafter, blood pressure started to decrease gradually. Maximum reduction was obtained after 4-5 h. Twenty minutes after administration of propranolol, heart rate and plasma renin activity were reduced, and remained so during the following 8 h. Supine plasma noradrenaline concentration did not change significantly after propranolol, but standing levels, showed a tendency to increase as blood pressure fell. Twenty minutes after administration of furosemide, plasma renin activity was increased and remained elevated during the following 8 h. Heart rate and plasma noradrenaline concentration were unchanged after 20 min, but both increased gradually as blood pressure started to fall. The results show that intravenous administration of both propranolol and furosemide leads to a delayed reduction of blood pressure. The increase in total peripheral resistance, which prevents blood pressure from falling acutely after intravenous injection of propranolol, is not reflected in an acute rise in plasma noradrenaline. The delayed hypotensive response does not seem to be due to a return of sympathetic activity to pretreatment levels, since plasma noradrenaline concentration shows a tendency to rise as blood pressure falls.

Adult↗
PubMedDate not supplied

Influence of prolonged submaximal exercise on the pharmacokinetics of verapamil in humans.

The influence of prolonged submaximal exercise on the pharmacokinetics of verapamil was studied in normal volunteers both after i.v. injections of 0.13 mg/kg body weight as well as after one oral dose of 80 mg of the calcium entry blocker. Each dose was given on a rest day and on an exercise day. On the rest day, the terminal phase half-life (t1/2) of verapamil averaged 161 +/- 23 min after i.v. injection of the drug. The total clearance was 772 +/- 125 ml/min, and the area volume of distribution was 198 +/- 53 L. These parameters were not altered on the exercise day. Neither did exercise have any influence on the pharmacokinetic parameters determined after oral application of verapamil. This study shows that prolonged submaximal exercise has no influence on the pharmacokinetics of verapamil.

Administration, Oral↗
PubMedDate not supplied

Ambulatory 24-h blood pressure monitoring in essential hypertensives treated with the angiotensin-converting enzyme inhibitor ramipril.

A double-blind, crossover study was carried out on the antihypertensive effect of 5 mg ramipril. Continuous 24-h blood pressure monitoring was performed on 15 essential hypertensives [mean (+/- SD) blood pressure 155.2 +/- 6.5/101.3 +/- 4.8 mmHg], 24 h prior to treatment and 48 h after having received either antihypertensive therapy or placebo; the patients taking part in the study had not taken any antihypertensive treatment 4 weeks prior to the beginning of the trial. After receiving 5 mg ramipril the mean 24-h blood pressure was significantly (P less than 0.05) reduced to 148.3 +/- 5.8/91.5 +/- 5.5 mmHg. After 48 h the blood pressure increased to 153.1 +/- 4.8/96.0 +/- 6.4 mmHg. In the placebo group there was only a slight, non-significant reduction in blood pressure on day 1 (154.3 +/- 6.9/97.3 +/- 5.7 mmHg) and during day 2 the blood pressure increased to 155.4 +/- 5.3/99.5 +/- 5.9 mmHg. The results showed that a once-daily administration of 5 mg ramipril produced a reduction in blood pressure, which lasted 24 h. This simple therapeutic regime offers the advantage of being easy for patients to follow and, therefore, promotes compliance with therapy.

Adult↗
PubMedDate not supplied

Circadian blood pressure rhythms in elderly hypertensive patients.

Blood pressure was recorded for 24 h in 121 essential hypertensive patients aged between 20 and 90 years. To characterize the circadian blood pressure rhythm, the differences between the daytime blood pressures (recorded at 8-min intervals between 8 a.m. and 10 p.m.) and the night-time blood pressures (recorded at 30-min intervals between 10 p.m. and 8 a.m.) were calculated. The difference between daytime and night-time blood pressures was significantly (P less than 0.01) decreased in elderly hypertensive patients aged between 65 and 90 years compared with in those aged 20-39 years. In patients with heart insufficiency the circadian blood pressure rhythmicity was significantly (P less than 0.05) further reduced compared with in uncomplicated hypertensives. This may be explained by increased sympathetic tonus in patients with heart insufficiency and reduced vascular compliance may be the cause of the overall reduced circadian blood pressure rhythmicity in elderly hypertensive patients.

Adult↗
PubMedDate not supplied

Acute hypertension after renal allograft rejection therapy with OKT3 monoclonal antibody.

Acute rejection of renal allografts was treated with the monoclonal antibody OKT3 given intravenously. A variety of adverse events were observed on days 1 and 2 following treatment with 5 mg/day OKT3 for 10 days including heart failure, pulmonary oedema and hypertension. Continuous monitoring of 19 patients treated with OKT3 for acute renal allograft rejection detected a transient increase, lasting 2 h, in systolic and diastolic blood pressures on day 1. A larger increase in systolic and diastolic pressures lasting 11-13 h was observed on day 2. Treatment with 5 mg OKT3 on day 3 did not significantly increase systolic or diastolic pressure. It is concluded that OKT3 can aggravate hypertension and hypertensive emergencies may be encountered during the initial phase of OKT3 treatment.

Acute Disease↗