There is no known drug interaction between Prevacid (lansoprazole) and Contrave (bupropion; naltrexone). They are considered safe to take together. However, it is important to follow the proper administration instructions for each drug for maximum effectiveness.
Prevacid: Administer on an empty stomach, 30—60 minutes before meals. If given once daily, administer before the first meal of the day.
Contrave: Administer by mouth in the morning and in the evening. May be administered with or without food; avoid administering with high-fat meals due to significant increases in bupropion and naltrexone systemic exposure.