Search results for "Atenolol"

Accumulation and Adverse Effects of Metoprolol and Propranolol After Concurrent Administration of Cimetidine

1983

Pharmacokinetics of metoprolol, propranolol and atenolol were investigated in six healthy volunteers following 7 days of oral monotherapy with these drugs and after 7 days concurrent administration of each of these betareceptor antagonists with cimetidine. Application of cimetidine did not lead to any interaction with atenolol, whereas mean peak plasma levels of metoprolol were increased by 70%, and those of propranolol by 95% due to concurrent administration of cimetidine (p < 0.05). The AUC of the two last mentioned beta blockers behaved similarly (p < 0.05). Measurement of exercise-induced tachycardia on the 6th day of administration showed no differences between monotherapy with the bet…

Effects of Norepinephrine and Cardiotrophin-1 on Phospholipase D Activity and Incorporation of Myristic Acid Into Phosphatidylcholine in Rat Heart

2004

The present study is part of a project on phospholipase D (PLD) in cardiac hypertrophy and analyzed effects on PLD activity of two growth stimuli, norepinephrine (NE) and cardiotrophin-1 (CT-1), in incubated rat heart. Phosphatidylcholine (PC) was labeled by 3H-myristic acid. PLD produced 3H-phosphatidylethanol (3H-PEth) from 3H-PC in the presence of ethanol and maintained a basal formation of 3H-PEth. Short-term and long-term exposure to NE for 2 or 13 h, respectively, enhanced the formation of 3H-PEth, which was blocked by prazosin. Long-term pretreatment with NE or CT-1 increased the incorporation of 3H-myristic acid into PC, which was blocked by atenolol. When the 3H-PEth formation was …

Beta-adrenoceptor stimulation enhances transmitter output from the rat phrenic nerve.

1988

Abstract 1. Neurally-evoked output of newly synthesized [3H]-acetylcholine from the rat phrenic nerve was measured in the absence of cholinesterase inhibitors. 2. Noradrenaline and isoprenaline enhanced neurally-evoked transmitter output markedly. Moreover, immediately after the application of noradrenaline the basal tritium efflux increased significantly. 3. Pretreatment with propranolol (0.1 mumol l-1) or atenolol (0.3 mumol l-1) completely prevented the stimulatory effect of noradrenaline and isoprenaline on evoked transmitter output. 4. The facilitatory effect of isoprenaline declined, when the exposure time was increased. This observation supports the assumption that beta-adrenoceptors…

An exploratory study of two Caco-2 cell models for oral absorption: A report on their within-laboratory and between-laboratory variability, and their…

2010

In 2005, the European Centre for the Validation of Alternative Methods (ECVAM) sponsored a study aimed at evaluating the reproducibility (between-laboratory and within-laboratory variability) and the predictive capacity of two in vitro cellular systems — the Caco-2/ATCC parental cell line and the Caco-2/TC7 clone — for estimating the oral fraction absorbed (Fa) in humans. Two laboratories, both of which had experience with Caco-2 cultures, participated in the study. Ten test chemicals with documented in vivo oral absorption data were selected. Atenolol, cimetidine and propranolol were included as reference compounds for low, medium and high intestinal absorption, respectively. Transport ex…

Effects of four different anti-hypertensive treatments on cardiac arrhythmias and transient episodes of myocardial ischemia in hypertensives with lef…

2000

Single Intravenous Dose Kinetics and Accumulation of Atenolol in Patients with Impaired Renal Function and on Hemodialysis

1980

The concentration of atenolol in plasma and urine was determined following an intravenous (i.v.) dose given to 17 hypertensive patients with a glomerular filtration rate (GFR) between 5 and 105 ml/min and in 4 patients on hemodialysis. In patients with normal renal function the mean half life of elimination was calculated to be 6.8 h. This value increased to a mean of 50.1 h in patients with a GFR below 10 ml/min. In patients on hemodialysis the half life of elimination was about 4 h. The elimination rate constants as well as the body and renal clearances of atenolol have a significant correlation with the GFR. Although accumulation of atenolol was observed, especially after multiple oral d…

Clinical pharmacokinetics of atenolol — A review

1982

Atenolol is a hydrophilic betareceptor blocking drug, which is predominantly eliminated via the kidneys, only about 5% of the atenolol is metabolised by the liver. After oral administration atenolol is incompletely absorbed from the intestine, so about 50% of the beta blocker are finally biovailable. In plasma only 3% of atenolol are protein-bound. There exists a linear relationship between the atenolol plasma levels and the degree of beta blocking effect measured by inhibition of the exercise-induced tachycardia. No correlation was found between plasma levels of atenolol and blood pressure lowering activity of the drug. After oral administration elimination half life of atenolol is calcula…