Oral administration is one of the most common and convenient ways of drug delivery, but drugs must be digested and absorbed after oral administration in order to play its proper role. There are many factors that affect the digestion and absorption of drugs, which are closely related to the sequence of eating, some drugs must be taken before meals, some need to be taken after meals. Drugs that should be taken on an empty stomach before meals are: 1, intestinal anti-infective drugs, so such drugs require a high concentration of drugs in the intestine, eating will reduce the concentration of drugs; 2, stomach wall protection drugs, because after taking such drugs will be dispersed in the stomach and form a protective film in the stomach wall, if taken at the same time with food or after meals, the drug will be mixed with food and not play a role; 3, enteric coated tablets, because such drugs need to After reaching the intestine to digest and absorb, and eating will affect the emptying of the stomach, delaying its digestion and absorption; 4, rifampicin, ampicillin and other drugs due to the easy adsorption of fiber in the food to reduce absorption, should also be taken before meals. 5, in addition, certain deworming drugs, laxatives, etc. also need to be taken before meals. Drugs that should be taken after meals are: 1, cod liver oil and other fat-soluble drugs, because fat-soluble drugs can be dissolved in the fat in food, more easily absorbed; 2, digestive drugs and food taken at the same time, its digestive effect is better. 3, most drugs can be taken after meals, especially those with serious gastrointestinal reactions, after meals can reduce the stimulation of drugs on the gastrointestinal tract. In addition, do not drink alcohol when taking drugs.