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Biomedical subjects

M E McNabb

Publications and source records attributed to M E McNabb.

9 recordsLinked to original sources
PubMed1985

Nicotine tolerance questionnaire scores and plasma nicotine: no correlation.

A questionnaire has been proposed to estimate degree of nicotine tolerance and thereby to rate the physical dependence of cigarette smokers. To examine its validity, 97 persons entering a smoking cessation clinic completed the Tolerance Questionnaire and gave late afternoon blood specimens for nicotine determination. There was no correlation between questionnaire scores and plasma nicotine levels. None of the questions had discriminatory value. A simple, nonchemical method of indicating degree of nicotine tolerance has not yet been validated.

Adult↗
PubMed1984

Chewing nicotine gum for 3 months: what happens to plasma nicotine levels?

Techniques that help patients stop smoking should also reduce their exposure to agents such as nicotine. The mean plasma nicotine levels in 50 subjects while they were still smoking and then while they were chewing pieces of gum containing either 2 or 4 mg of nicotine over a 12-week period of abstinence were 35, 9 and 23 ng/mL (217, 56 and 143 nmol/L) respectively. A small number of subjects given an unlimited supply of gum used 14 to 24 pieces of 4-mg gum daily and had plasma nicotine levels exceeding the levels achieved while smoking. There were no acute symptoms necessitating medical intervention associated with these excessive levels. Side effects were uncommon and usually controllable. When simple dosage rules are followed people who chew nicotine gum for a few months to stop smoking lower their exposure to nicotine.

Adult↗
PubMed1984

Effect of nicotine chewing gum on plasma nicotine levels of cigarette smokers.

This study was designed to determine whether the use of nicotine chewing gum modifies the inhalation and absorption of nicotine by cigarette smokers. Our subjects, 12 subjects who smoked cigarettes regularly, were studied for 4 days. On the first day, they smoked as usual, and on the second, third, and fourth days they also chewed a placebo gum, 2-mg nicotine gum, or 4-mg nicotine gum. They were instructed to smoke as usual throughout the study. Mean plasma nicotine concentration was 29.5 ng/ml with the placebo gum, 30.9 ng/ml with the 2-mg gum, and 40.7 ng/ml with the 4-mg gum. Peak carbon monoxide level was lower with nicotine gum than with placebo gum. Data indicate self-regulation of blood nicotine levels. The subjects appear to have compensated almost completely for the increased intake of nicotine from the 2-mg nicotine gum by decreasing the inhalation of tobacco smoke. Nicotine compensation provided by the 4-mg nicotine gum is only partial.

Absorption↗
PubMed1983

Amount of nicotine and carbon monoxide inhaled by smokers of low-tar, low-nicotine cigarettes.

In 76 smokers, correlations between plasma nicotine and alveolar carbon monoxide levels of the individual smoker and the nicotine and CO yields of his cigarette were very poor. In 24 smokers of low-nicotine, low-tar cigarettes, mean alveolar CO levels did not differ from those of smokers of regular cigarettes. Mean plasma nicotine levels were lower in smokers of low-nicotine cigarettes, but a wide overlap of individual values occurred. The implication that an individual shifting to ultra-low-tar cigarettes reduces risks of cardiopulmonary disease is unwarranted.

Carbon Monoxide↗
PubMed1982

Plasma nicotine levels produced by chewing nicotine gum.

Nicotine chewing gum is designed to maintain plasma nicotine levels during a smoking cessation effort while the individual copes with the loss of the repetitive behavioral components of smoking. The plasma nicotine levels obtained with hourly gum chewing were compared with levels obtained with cigarette smoking in nine patients with lung disease. Chewing 2- and 4-mg nicotine gum hourly produced mean steady-state plasma nicotine levels of 11.8 and 23.2 ng/mL, respectively. This compares with a mean plasma nicotine trough level during usual smoking of 15.7 ng/mL and a mean trough level of 18.3 ng/mL with hourly smoking of a cigarette with a nicotine yield of 1.1 mg. Few side effects were seen with the use of either the 2- or 4-mg gum. In a short-term study, nicotine gum proved an acceptable source of nicotine for aiding smoking cessation.

Carboxyhemoglobin↗