The effect of environmental tobacco smoke on the dose requirements of rocuronium in children.
ABSTRACT Smoking affects the pharmacodynamic and pharmacokinetic behaviour of several drugs. The aim of this study was to evaluate the effects of environmental tobacco smoke on onset and recovery time after single dose rocuronium in children.
Forty children between 4 and 10 years were enrolled into the study. Children who have no familial smoking history were included in the first group whereas passive smokers included in the second group. Sevoflurane in 50% O2 and 50% N2O was used for induction of anaesthesia. Evoked adductor pollicis electromyography was used to monitor neuromuscular block. The T95 and T25 values were recorded.
The T95 values (+/-sd) for rocuronium were 110.1 +/- 39.3 s and 79.3 +/- 35.6 s for group 1 and group 2, respectively (P < 0.05). The T25 value of group 2 was 40.1 +/- 10.6 min and compared with group 1 values (30.85 +/- 7.02 min) it was significantly longer (P < 0.01).
This study shows that passive smoking children consume less rocuronium than nonsmokers during similar anaesthesia. We think that a history of passive smoking must also be taken into consideration during preoperative evaluation of paediatric patients.
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ABSTRACT: With the ever-increasing population of cigarette smokers, the potential for cigarette smoke to affect drug therapy both pharmacokinetically and pharmacodynamically is significant. The overriding pharmacokinetic effect is increased drug metabolism through the induction of liver enzymes. The constituents of tobacco smoke, primarily nicotine, have their own pharmacological effects which may potentiate or antagonise the desired pharmacological effect of a particular drug, thereby affecting its efficacy. Furthermore, end-organ responsiveness may also be altered by tobacco. These latter 2 aspects constitute altered clinical pharmacodynamics. Approximately 30 drugs have been evaluated in terms of cigarette smoking. Induction of liver enzymes has been shown to increase the metabolism of imipramine, meprobamate, oestrogens, pentazocine, phenylbutazone, theophylline and warfarin. Nicotine has been shown to inhibit diuresis, alter ulcer healing, impair subcutaneous absorption, affect protein binding and stimulate catecholamine release; these effects have been evaluated in terms of therapy with frusemide (furosemide), histamine H2-antagonists, insulin, lignocaine (lidocaine) and beta-blockers, respectively. The interactions have not been correlated with clinical significance in all cases. Diminished end-organ responsiveness may account for reduced drowsiness in smokers receiving chlorpromazine and benzodiazepines, compared with non-smokers. Smoking has been associated with diminished pain tolerance, requiring increased dosages of morphine, pethidine (meperidine) and propoxyphene. Enzyme-inducers such as carbamazepine, phenytoin and phenobarbitone appear to be minimally affected by cigarette smoke, perhaps because hepatic enzymes are already maximally stimulated. Codeine, corticosteroids and nortriptyline do not appear to be affected by cigarette smoke. The bioavailability of glutethimide is higher in smokers, but this has not been associated with greater efficacy. The effect of smoking on paracetamol (acetaminophen) has been variable, depending on the extent of smoking, and does not appear to be of clinical significance.Clinical Pharmacokinetics 09/1989; 17(2):90-108. · 6.11 Impact Factor
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ABSTRACT: Controversial data about the effect of smoking on the dose-requirements and the pharamcodynamics of rocuronium have been reported recently. This study was conducted to evaluate the dose-requirements and the pharmacodynamics of rocuronium in smokers using target controlled infusion. The dose-requirements of rocuronium for 60 min relaxation, using target controlled infusion, given under intravenous anaesthesia with propofol, fentanyl and nitrous oxide was studied in 37 smokers and 37 non-smokers. Initially 450 microg x kg(-1) rocuronium were administered, neuromuscular effects were quantified by recording the single twitch response of the adductor pollicis muscle after ulnar nerve stimulation using a force transducer, and the neuromuscular block was kept at 80% by target controlled infusion throughout the procedure. The dose-requirements for one hour relaxation were 867 +/- 116 microg x kg(-1) x hr(-1) for smokers (S) and 839 +/- 149 microg x kg(-1) x hr(-1) for non-smokers (NS). The duration to 10% and the spontaneous recovery from 25% to 75% of the control twitch response also showed no differences between S (17.2 +/- 3.4 min, 10.6 +/- 0.9 min) and NS (18.9 +/- 4.3 min, 10.9 +/- 3.2 min), as well as maximum block, onset time and infusion rate. Smoking does not alter the dose-requirements for rocuronium and no effects on the onset time, degree of block, time to maximum block, duration 10% and spontaneous recovery index were observed.Canadian Journal of Anaesthesia 05/2000; 47(4):347-9. · 2.13 Impact Factor
Article: Smoking and drug metabolism.Pharmacology [?] Therapeutics 02/1981; 15(2):207-21. · 7.79 Impact Factor