Fernandez, Lenora; Covey, Lirio; Mortera, Lalaine; Silos, Manuel Hector; Hernandez-Sebastian, Rosalyn; Baylon, Madeline University of the Philippines-Manila, Manila/ Columbia University, United States/ University of the Philippines, Philippines
Smoking is a persistent problem in the Philippines with the prevalence remaining at 45 percent for the past seven years. A survey among Filipino smokers showed that all of those who attempted to quit resumed smoking within a month from the attempt. Smoking relapse therefore has to be investigated since this contributes to the continuing high prevalence of smoking in the country. This study primarily aimed to determine if extending pharmacologic intervention through the use of bupropion hydrochloride SR for six months can reduce smoking relapse. The other objectives of the study were to determine the safety and tolerability of prolonged use of bupropion hydrochloride SR and to determine the profile of Filipino smokers in relation to the phenomenon of relapse. This was a randomized, double-blind, placebo-controlled study. Willing smokers underwent individualized smoking cessation sessions and initially took sustained-release buproprion hydrochloride at 300 mg/day for eight weeks (open phase). Smokers who reported not smoking and whose urine cotinine levels were negative during the last two weeks of the open-label phase were eligible for randomization. The randomized subjects either took bupropion hydrochloride at 150-300 mg/day or a placebo for another 16 weeks (maintenance phase) and were monitored for another six months without any placebo medication. Smoking relapse was defined as a self report of smoking for seven consecutive days from the start of the maintenance phase and/or if they missed more than two consecutive visits. Time to first relapse, safety profile and relapse indicators were also determined. Eighty- four smokers were enrolled and 48 (58 percent) were randomized after being biochemically confirmed to be abstinent from smoking during the final two weeks of the open-label phase. Of the 24 subjects randomized to receive the active medication, four (16.7 percent) relapsed before the end of week 48. Of the 24 subjects randomized to placebo, seven (29.2 percent) resumed smoking by the end of the study. This difference was not statistically significant (odds ratio 0.49 (95 percent CI 0.1-2.32; p value 0.303). The median time to relapse was longer for the bupropion compared to the placebo group (322.8 hours (95 percent confidence interval: 277.2-368.4) for bupropion group versus 276.5 hours (95 percent CI: 213.5-339.5) for placebo group), however, this difference was not statistically significant (p<0.320). The adverse events were restlessness, anxiety, irritability, sleep disturbance, impaired concentration, mood swings, craving to smoke and increased appetite. Some of these adverse events persisted with active drug intake, however, there was no statistically significant difference between the bupropion and placebo groups. No specific demographic characteristics differentiated the relapsers. Smoking relapse was 16-29 percent among Filipinos in one year and prolonged administration of bupropion hydrochloride SR for six months did not decrease the occurrence or delay the onset of relapse. No significant adverse effects were encountered with the prolonged use of bupropion hydrochloride. There was also no specific demographic feature or risk factor associated with smoking relapse.