Safety of Transdermal Nicotine in Cardiac Patients
Source: Joseph AM. N Engl J Med 1996;335: 1792-1798.
Many cardiologists are reluctant to prescribe transdermal nicotine to cardiac patients, despite the benefits of smoking cessation, due to concern about safety in this patient population. Thus, Joseph et al conducted a randomized, double-blind, placebo-controlled trial of 10 weeks of transdermal nicotine in decreasing doses to aid smoking cessation in 584 veteran outpatients with at least one cardiovascular disorder that could be aggravated by nicotine. One or more cardiac events occurred in 95 patients during the 10 weeks; equal numbers of the nicotine subjects and the placebo patients (16% each) had at least one event. After 14 weeks, abstinence from smoking was 21% in the nicotine group and 9% in the placebo group (P < 0.001), but were not significantly different after 24 weeks (14% vs 11%). Events were not related to smoking status in either group. The distribution of side effects usually attributed to nicotine was not different between the two groups. This study demonstrates a high rate of events in smoking males with cardiovascular disease, but no increase in events on the nicotine patch. There are several reasons for this finding. First, nicotine patches produce lower blood levels of nicotine than cigarette smoking. Second, patches deliver a steady dose of nicotine, allowing the body to adjust to the catecholamine stimulation, whereas smoking produces intermittently high levels. Third, nicotine alone does not reduce oxygen carrying capacity, increase thrombogenesis, or promote atherosclerosis. Theoretically, transdermal nicotine may be safer than smoking, and the equal event rates in the two groups in this study may be due to the high rate of continued smoking in the nicotine group (58%). Contrary to what would be expected, patch users who continued to smoke did not have a higher event rate, probably because patch users smoke fewer cigarettes. Thus, nicotine patches are safe in patients with cardiovascular disease, but smoking cessation efficacy is modest and recidivism is high.mhc