Comparison of the effects of combined nicotine replacement therapy vs. cigarette smoking in males

This open study assessed the effects of nicotine replacement therapy (NRT) on the normalizing of exhaled carbon monoxide (CO), transcutaneous partial oxygen tension (tcpO(2)), plasma cotinine and thiocyanate levels, and cardiovascular risk markers in abstinent subjects compared with untreated smokers after 4, 8, 12, and 26 weeks. The trial enrolled 197 subjects in two parallel groups: 164 subjects who received NRT (patch plus gum) for 12 weeks and 33 untreated smokers (controls). At 26 weeks, 123/164 participants in the treatment group had completed the study; 51/123 (41.5%) sustained abstinence from smoking, whereas 72/123 (58.5%) had relapsed. Changes in cotinine (abstainers: 291.6 ng/ml at baseline vs. 27.3 ng/ml at week 26; p<.0001) and thiocyanate levels (abstainers: 10.4 ng/ml at baseline vs. 6.2 ng/ml at week 26; p<.0001) and expired CO (abstainers: 30.4 ppm at baseline vs. 4.2 ppm at week 26; p<.0001) accurately reflected the changes in smoking and/or NRT use in both abstainers and relapsers. After they stopping smoking, tcpO(2) significantly improved in abstainers (34.9 mmHg at baseline vs. 50.4 mmHg at week 26; p<0.0001). Inverse correlations between the number of daily cigarettes and plasma cotinine, thiocyanate, and exhaled CO levels were observed in both relapsers and smokers. A clinically significant increase in HDL cholesterol (39.0 vs. 44.7 mg/dl; p<.0001) occurred in the abstainers between baseline and study end. Use of combination NRT to achieve abstinence resulted in marked improvements in biochemical parameters in abstainers and partial improvements in relapsers. The safety of combination NRT was confirmed by the absence of overdose-related adverse events.