Smoking cessation – Varenicline
The main drugs that have shown efficacy in smoking cessation include bupropion and varenicline. Medication for smoking cessation should be offered to all smokers who want and are trying to quit, unless there are medical contraindications.
Varenicline works by stimulating nicotine receptors, thereby reducing the withdrawal symptoms and also reduces the feeling of euphoria caused by smoking. Various surveys in the U.S. and Japan have shown that varenicline is more effective than placebo for smoking cessation for at least 6 months of observation. It has a 3-fold success rates compared with placebo in smoking cessation.
Further investigations (about 2,000 smokers participated) have shown that varenicline is more effective than bupropion in smoking cessation. Also, it appears that varenicline has better results in smoking cessation rates over nicotine replacement therapy (especially when the latter contains only one kind of substitute and not a combination).
The recommended dose of varenicline is 0.5 mg daily for 3 days, then 0.5 mg twice daily for 4 days, then 1 mg twice a day for the rest of the time remaining for 12 weeks total treatment. Dose adjustment is required in smokers who have kidney problems. It is advised to stop smoking one week after the start of the drug because the levels of drug in the blood need about a week to rise and stabilize. Probably, smokers who succeeded in the 12 weeks program to stop smoking, need to continue the drug for another 12 weeks to more successful and lasting results.
The two main problems in the administration of varenicline are neuropsychiatric and cardiovascular events. As with other smokers who try quitting smoking, so in those receiving varenicline, it is recommended a reassessment at 1 week after initiation of the drug. It is also proposed for the patient to communicate with the doctor and the immediate cessation of the drug in cases where there is a change in behavior or a cardiovascular event.