The best time to take rifampicin should be before meals or fasting, usually one hour before meals or fasting at night, mainly can make the drug is not more mixed and diluted by the food in the stomach, can play a better efficacy. Most of the drugs will be affected by the absorption of food, take before meals bioavailability is higher, but oral rifampicin before meals also have certain side effects, mainly gastrointestinal adverse reactions, such as gastrointestinal adverse reactions will be more pronounced, especially half an hour before meals, if you can’t tolerate it, oral drugs appear obvious nausea, vomiting, or even abdominal pain, it is still recommended to take half an hour after a meal.