摘要:

Pharmacokinetics of drugs taken in overdose may differ from those observed following therapeutic doses. Differences are due both to dose-dependent changes and to effects of drugs or pathophysiological consequences of the overdose on kinetics. Dose-dependent changes in rate and extent of absorption, bioavailability (saturation of first-pass metabolism), distribution (saturation of protein binding sites) and metabolism are discussed. Gastrointestinal motility is affected both by specific drug actions, such as delayed gastric emptying by anticholinergic drugs, and by general nervous system depression caused by many drugs. Drug-induced circulatory insufficiency may retard tissue distribution and reduce clearance. Disturbances in blood and urine pH may alter distribution and clearance of weak acids and bases. Drug-induced renal or hepatic failure can significantly decrease clearance. Hypothermia is a common complication of drug overdose and might retard distribution and also reduce clearance.The data concerning pharmacokinetics during overdose are usually incomplete and difficult to interpret. Doses and times of ingestion are uncertain, duration of blood and urine sampling is often inadequate to distinguish absorption from distribution and elimination phases, active metabolites are not measured, protein binding is not determined and clinical features of patients not adequately described. We have, however, reviewed available data for salicylate, paracetamol (acetaminophen), barbiturates, ethchlorvynol, glutethimide, chloral hydrate, tricyclic antidepressants, lithium, phenytoin, ethanol, theophylline, digoxin, amphetamine and phencyclidine.

ISSN:0312-5963    

出版商:ADIS    

年代:1981

数据来源: ADIS

摘要:

The medical literature is replete with dosing guidelines for patients with renal dysfunction. Altering dosing regimens in such patients is particularly important with drugs with a narrow therapeutic index, such as digoxin and the aminoglycoside antibiotics. A variety of methods have been used to devise dosing nomograms.This article reviews the salient features of different methods, and addresses the issues of predictability or unpredictability in attaining desired plasma concentrations of drug. It is suggested that therapy must be individualised, and that the clinician can best plan his therapy by understanding the principles on which dose adjustment is based, rather than using the same nomogram or guideline for each and every patient.

ISSN:0312-5963    

出版商:ADIS    

年代:1981

数据来源: ADIS

ISSN:0312-5963    

出版商:ADIS    

年代:1981

数据来源: ADIS

ISSN:0312-5963    

出版商:ADIS    

年代:1981

数据来源: ADIS