摘要:

Clinical Pharmacology and Therapeutics(1989)46, 245–249; doi:10.1038/clpt.1989.1

ISSN:0009-9236    

DOI:10.1038/clpt.1989.134

年代:1989

数据来源: WILEY

摘要:

Clinical Pharmacology and Therapeutics(1989)46, 250–256; doi:10.1038/clpt.1989.1

ISSN:0009-9236    

DOI:10.1038/clpt.1989.135

年代:1989

数据来源: WILEY

摘要:

This study determined the total clearance of propranolol and the partial clearances through each of its three primary metabolic pathways after administration of an 80 mg single oral dose in 28 young, white subjects (13 women; 15 men). The oral clearance of propranolol was significantly higher (63%,p<0.02) in the men (65.7 ±7.7ml/min/kg; mean ± SE) than in the women (40.2 ± 6.2 ml/min/kg). This sex difference was mainly attributable to a 137% higher clearance through the P‐450‐mediated side‐chain oxidation in the men (p<0.001). There was also a 52% higher clearance through glucuronidation in the men (p<0.02). In contrast, the clearance through the P‐450–mediated ring oxidation was not different between men and women. After administration of simultaneous intravenous doses of hexadeuterium‐labeled drug (0.1 mg/kg) to 11 of the subjects, there were no differences between men and women in volume of distribution or half‐life. Moreover, there were no sex differences in plasma and blood binding of propranolol. This study thus demonstrates that higher plasma levels of propranolol occur in women than in men after oral doses and suggests that some drug metabolizing enzymes, but not others, are regulated by sex hormones in human beings.Clinical Pharmacology and Therapeutics(1989)46, 257–263; doi:10

ISSN:0009-9236    

DOI:10.1038/clpt.1989.136

年代:1989

数据来源: WILEY

摘要:

Overdose with modified‐release pharmaceuticals is an increasing phenomenon. This study examines whole‐bowel irrigation as a potential decontamination strategy after overdose with enteric‐coated acetylsalicylic acid and compares it with administration of activated charcoal in sorbitol, which is currently the recommended intervention. A three‐phase randomized crossover protocol was used in 10 adult volunteers. Each volunteer ingested nine 325 mg doses of enteric‐coated acetylsalicylic acid on three occasions, with at least 1 week between each administration period. Serum samples were analyzed for salicylic acid concentration by HPLC. Both interventions decreased peak salicylic acid concentration, time‐to‐zero salicylic acid concentration, and AUC when compared with control (p<0.01). Whole‐bowel irrigation was superior to activated charcoal in sorbitol by all three criteria (p<0.05). Adverse effects were qualitatively and quantitatively greater during activated charcoal in sorbitol, and the volunteers preferred whole‐bowel irrigation over charcoal in sorbitol. Our data suggest that whole‐bowel irrigation should be considered for overdose of other modified‐release pharmaceuticals.Clinical Pharmacology and Therapeutics(1989)46, 264–271; d

ISSN:0009-9236    

DOI:10.1038/clpt.1989.137

年代:1989

数据来源: WILEY

摘要:

A randomized, double‐blind, and placebo‐controlled study was performed in 10 healthy volunteers to evaluate a possible interaction between adenosine and nicotine in human beings. The infusion of adenosine alone (0.07 mg/kg/min) induced an increase in heart rate of 4.7 beats/min versus 0.2 beats/min after placebo administration (p<0.02). The infusion of adenosine alone induced a decrease in finger skin temperature compared with placebo administration (−1.0° versus 0.0° C,p<0.01). When compared with baseline values, nicotine gum chewing increased systolic and diastolic blood pressures by 6.2 and 7.0 mm Hg, respectively (p<0.001), heart rate by 5.5 beats/min (p<0.01), and plasma adrenaline levels by 0.03 nmol/L (p<0.025), whereas skin temperatures fell by 1.3° C (p<0.001). The nicotine‐induced increase in heart rate was larger during adenosine infusion than during placebo administration (14.9 versus 5.5 beats/min,p<0.001), whereas the increment of diastolic blood pressure was lower (1.1 versus 4.0 mm Hg,p<0.05). The increment in systolic blood pressure was not altered by concomitant adenosine infusion. The rise in plasma noradrenaline levels during the combined administration of nicotine and adenosine differed significantly from the response to nicotine alone (+ 0.23 versus − 0.05 nmol/L,p<0.02). We concluded that, in human beings, the characteristic hemodynamic response to adenosine infusion is enhanced by nicotine.Clinical Pharmacology and Therapeutics(1989)46, 272–278; doi:10.103

ISSN:0009-9236    

DOI:10.1038/clpt.1989.138

年代:1989

数据来源: WILEY

摘要:

We determined whether the β‐blockade disappearance rate would determine the degree of subsequent transient β‐adrenoceptor hyperresponsiveness after abrupt withdrawal of a β‐adrenoceptor drug. In a single‐blind randomized study, 10 healthy men took a placebo for 1 week and then took nadolol one time a day (t½, 18 to 24 hours) or propranolol three times a day (t½, 4 to 6 hours) in doses that were increased weekly for 4 weeks to reach 240 mg per day. β‐Receptor responsiveness was assessed before and repeatedly after abrupt drug withdrawal by infusion of isoproterenol and epinephrine and by ergometer exercise. In the 13 days after drug discontinuation, peak β‐receptor sensitivity correlated (p<0.05) with the disappearance rate of β‐blockade as assessed by heart rate responses to isoproterenol (r= 0.68) and to submaximal exercise (r= 0.62) and by diastolic blood pressure responses to isoproterenol (r= 0.86) and epinephrine (r= 0.86). Plasma catecholamine levels and renin activity showed no overshoot, β‐Blockers with long plasma t½values may prevent β‐blocker withdrawal syndromes by means of “self‐tapering.”Clinical Pharmacology and Therapeutics(1989)46,

ISSN:0009-9236    

DOI:10.1038/clpt.1989.139

年代:1989

数据来源: WILEY

摘要:

The influx of calcium into vascular smooth muscle cells is a major determinant of vasoconstriction, yet this concept has not been explored in congestive heart failure (CHF). We therefore used an “isolated” forearm model to assess the direct effects of the inhibition of calcium influx into vascular smooth muscle in 11 patients who had CHF, with use of the soluble dihydropyridine, nicardipine. Nicardipine produced a dose‐dependent increase of forearm blood flow and a reduction of resistance, without producing a systemic hemodynamic effect. Patients with the lowest baseline forearm blood flow levels had the greatest percentage increases in forearm blood flow (r= − 0.729,p<0.01), and a favorable metabolic effect was documented by a reduction in oxygen extraction across the forearm. This study demonstrated the importance of vascular smooth muscle intracellular calcium as a determinant of vasoconstriction in patients who have CHF.Clinical Pharmacology and Therapeutics(1989)46, 291–296; doi:10.1038/clp

ISSN:0009-9236    

DOI:10.1038/clpt.1989.140

年代:1989

数据来源: WILEY

摘要:

We investigated the effect of debrisoquin on propranolol metabolism in six normal subjects who were extensive metabolizers of debrisoquin. Each subject was studied on two occasions. On the first occasion, each subject received oral propranolol (80 mg) alone; on the second occasion, 7 days later, each subject received a dose of propranolol (80 mg) 30 minutes after the administration of oral debrisoquin (40 mg). Oral propranolol clearance was reduced 33% ± 16% (p<0.05) by the administration of debrisoquin. As predicted, the 4‐hydroxypropranolol partial metabolic clearance was significantly (p<0.05) inhibited by debrisoquin. However, the side‐chain oxidation pathway, as measured by naphthoxylactic acid, was also significantly (p<0.05) inhibited by debrisoquin. Debrisoquin administration did not change the renal clearance of any of the metabolites. These data support the usefulness of the in vivo inhibition model in the prediction of cosegregation of routes of metabolism. However, for propranolol, pathways of its metabolism that are not thought to cosegregate with debrisoquin were also inhibited.Clinical Pharmacology and Therapeutics(1989)46, 297–300; doi:10.1038/clpt.1

ISSN:0009-9236    

DOI:10.1038/clpt.1989.141

年代:1989

数据来源: WILEY

摘要:

Viqualine, a serotonin releaser and uptake inhibitor, was studied for its effects on consummatory behaviors (intake of ethanol and nonalcoholic beverages, cigarette smoking, and changes in body weight) in 29 men who were early‐stage problem drinkers between 21 to 55 years of age. Subjects were randomly assigned to receive a placebo and either 100 mg/day viqualine (n= 15) or 200 mg/day viqualine (n= 14) orally in a double‐blind crossover study. Viqualine administration and ethanol intake were assessed by self‐reports and by measurement of drug and ethanol concentrations in body fluids. Compared with placebo, 100 mg/day viqualine did not decrease ethanol intake. However, 200 mg/day viqualine significantly decreased the total number of drinks consumed in a 14‐day period (F1,12= 5.3;p<0.05). An increase in the number of abstinent days was significant only for those subjects who received the placebo first (F1,6= 11.3,p<0.02). Subjects reported a decreased interest in and decreased desire for alcohol during viqualine treatment. Patterns of response varied, but 64% of the subjects decreased the number of alcoholic drinks consumed and/or increased the number of days of abstinence by at least 25% during treatment with 200 mg/day viqualine compared with placebo treatment. Neither dose of viqualine had an effect on cigarette smoking or on consumption of nonalcoholic beverages, but subjects showed significant decreases in body weight with both doses. These findings indicate that viqualine both attenuates ethanol intake and reduces body weight in human beings.Clinical Pharmacology and Therapeutics(1989)46, 301–308; doi:10.1038/clp

ISSN:0009-9236    

DOI:10.1038/clpt.1989.142

年代:1989

数据来源: WILEY

摘要:

Clinical Pharmacology and Therapeutics(1989)46, 309; doi:10.1038/clpt.1989.143

ISSN:0009-9236    

DOI:10.1038/clpt.1989.143

年代:1989

数据来源: WILEY