Gastric mucosal protective agents The purpose of these drugs is to strengthen the barrier function of the gastric mucosa. The effect of the drug depends on the concentration of the drug in the stomach and the contact time between the drug and the gastric mucosa, so most of the drugs should be taken between meals in a semi-empty state, but there are different suitable times for specific drugs, such as montelukast and Metzolim-S taken between meals, aluminum thioglycollate taken one hour before meals and at night before bedtime, colloidal bismuth preparations and misoprostol taken half an hour before meals and at night at bedtime. Teprenone and others are taken half an hour after meals. Magnesium aluminum carbonate is also chewed one hour after meals and at bedtime at night, and can be added at any time when symptoms appear again. Antacids are mostly weak alkaline inorganic salts, such as aluminum hydroxide, magnesium oxide, magnesium trisilicate, calcium carbonate and compound preparations, can directly neutralize stomach acid, quickly relieve stomach pain, but the effect is short, more side effects, less than ideal efficacy, less application in recent years. It is appropriate to wait for the stomach contents nearly emptying and then give full play to the antacid effect, so 1 ~ 1.5 hours after meals and before going to bed to take the best. Compound preparations, etc. should be chewed and taken according to regulations. Acid-suppressing drugs are absorbed and act on the acid-producing cells (wall cells) of the stomach to inhibit gastric acid secretion, which is not as fast as antacids, but has a long duration of action, few side effects, outstanding efficacy and wide application. They include H2 receptor blockers (cimetidine, ranitidine, famotidine and nizatidine, etc.) and proton pump inhibitors (omeprazole, lansoprazole, pantoprazole, rabeprazole and esomeprazole, etc.). The former has no significant irritation to the gastric mucosa, absorption is not affected by gastric contents, and is generally taken half an hour after a meal, but there is no harm in taking it half an hour before or during a meal. The absorption of the latter is easily disturbed by food in the stomach, so it should be taken half an hour before a meal. Promoting drugs commonly used domperidone, cisapride or mosapride, are taken half an hour before a meal, to be eaten when the drug’s effect reaches its peak. Trimetbutine has a bidirectional regulation of gastrointestinal smooth muscle movement and is also taken half an hour before meals. The current regimen is a proton pump inhibitor or a colloidal bismuth preparation, plus two antibiotics or antimicrobials, the latter commonly being clarithromycin, hydroxybenzyl penicillin, metronidazole or tinidazole and furazolidone. To reduce the cost, H2 receptor blockers can be used instead of proton pump inhibitors, but the efficacy is also reduced. Clarithromycin is best taken half an hour before a meal, or after or with a meal if gastrointestinal irritation is present. The absorption of this drug is slightly delayed by food, but it has no effect on the total bioavailability. Amoxicillin is well absorbed after oral administration and is not affected by food, and can be taken before, after, or with meals. Metronidazole and tinidazole should be taken half an hour after meals to avoid or reduce the symptoms of gastrointestinal irritation that are more likely to occur. Scientific taking in order to play the maximum role of drugs, but in addition to taking stomach medicine, patients should first avoid spicy stimulating food to better protect their stomach.