Quit smoking prescription pills contain drugs like bupropion and Varenicline tartrate. They act on different parts of the brain to reduce cravings for nicotine and make smoking seem less pleasurable. There are some side effects associated with both these medications.

Bupropion can cause side effects like anxiety, headache, insomnia, dry mouth, and others, while Varenicline can cause nausea, constipation, headache, flatulence, sleep disturbances etc. Varenicline should not be used by people who have a history of mental illnesses, those who have kidney disease or seizures. It should also not be used by pregnant or breastfeeding women. Although its effects on the developing fetus or breastfeeding baby have not been studied, it is best avoided at these stages. This medicine should not be given to people younger than 18 years of age.

Varenicline can interact with other medications like insulin, warfarin, theophylline and others. Discuss these and other medications and vitamin or mineral supplements you are taking with your doctor. Bupropion should not be taken by people who are allergic to this medication. Those with seizures and eating disorders or mental illnesses should also avoid this medication. People, who are currently on thioridazine or those who have taken monoamine oxidase inhibitor within the past two weeks, should not take bupropion.