Participants
psychiatric illness, allergy
ALLERGY
The study was conducted at Duke University Health System, a large university health system in central North Carolina. Potential participants were daily smokers who had been referred to a clinical smoking cessation program. Potential participants were offered free medications and compensation for study participation. Inclusion criteria were that participants must be daily smokers for at least 1 year, aged at least 18 years, and willing to attempt smoking cessation. Exclusion criteria included pregnancy, use of multiple tobacco products, current use of smoking cessation medications, allergy or intolerance to study medications, medical illness requiring hospitalization, psychiatric illness requiring hospitalization, alcohol or sedative dependence requiring treatment, significant recent illicit substance use, or baseline exhaled 