A. Proton pump inhibitor and bismuth combined: Both drugs are commonly used in gastroenterology. Proton pump inhibitors can block the proton pump on the microcystic membrane of gastric wall cells, so that hydrogen ion discharge is blocked, which can rapidly increase the pH value in the stomach after oral administration and improve the effect of antibiotics on the elimination of H. pylori, and are mostly used clinically for the treatment of peptic ulcer, commonly used drugs are omeprazole, lansoprazole, pantoprazole, rabeprazole, etc. Bismuth agents such as colloidal bismuth subcitrate need to be deposited in the form of bismuth salts in the gastric mucosa under the action of gastric acid to protect the ulcer surface and play the role of anti-pylori. When the two are taken orally at the same time, bismuth cannot function effectively because of the loss of acidic environment. Therefore, bismuth should not be taken orally at the same time with proton pump inhibitors. If it must be applied at the same time, the dosing time should be staggered to avoid affecting the efficacy. Bismuth is used in the treatment of upper gastrointestinal bleeding: The damage of gastric mucosa caused by excessive secretion of gastric acid due to various factors is one of the common causes of upper gastrointestinal bleeding in patients. The gastric mucosa is mainly distributed with a large number of capillaries without smooth muscle walls, so the general effect of vascular hemostatic agents acting on smooth muscle cells is poor, while the use of acid-control agents can receive better results. The principle is that the clot is rapidly digested in gastric acid with a pH value of less than 5, and acidulants achieve hemostasis by raising the pH value in the stomach, promoting platelet aggregation, and inducing plasma coagulation. However, during the activity of upper gastrointestinal bleeding, oral bismuth such as colloidal bismuth subcitrate can affect the evaluation of bleeding due to the formation of sulfide in the stomach and black stool, on the other hand, it may affect the efficacy of acidulants, so it is not suitable for the treatment of upper gastrointestinal bleeding. Third, ecological agents combined with antibiotics: intractable diarrhea is often associated with the misuse of antibiotics leading to the dysbiosis of intestinal flora and the proliferation of conditionally pathogenic bacteria. Ecological agents are one of the main clinical treatment drugs. There are two types of live bacterial preparations in common use: one type of preparation such as rectified intestine, Mia BM tablets, etc. can consume a large amount of oxygen in the intestine, causing an anaerobic environment and promoting the growth of anaerobic bacteria to facilitate the restoration of the balance of the flora; the other type of drugs such as Rejuveno, Pepcid, etc. directly supplement the normal intestinal bacteria. In principle, live bacteria preparations are not used in combination with antibiotics to avoid affecting the efficacy. If you must apply ecological preparations and antibiotics at the same time, you can consider the application of dead bacteria preparations such as billion live capsules (yeast preparations) or Lortol, this type of preparation is not affected by antibiotics. Fourth, haloperidol in combination with acid preparations: Patients with intestinal infections often present clinically with diarrhea, blood in stool, urgency, and leukocytosis in stool examination. Quinolones have a broad antibacterial spectrum and are often used as the first choice of oral medication for intestinal infections. Because gastrointestinal symptoms often coexist, some clinicians often combine haloperidol with acidulants. However, acidifiers can interfere with the absorption of haloperidol, reducing blood levels and making it less effective. Magnesium aluminum carbonate can also affect the absorption of the drug, and should be avoided at the same time. Five, Similda combined with antibiotics: Similda contains natural double octahedral montmorillonite particles, which can cover the gastrointestinal mucosa to enhance the mucosal barrier, chelate bile salts, remove pathogenic bacteria and toxins, support the normal intestinal flora, reduce intestinal susceptibility and other effects, as the current treatment of diarrhea commonly used drugs. Antibiotics taken orally at the same time can be adsorbed and eliminated from the body by Simethicone. At the same time, Simethicone can form a protective film in the intestinal tract, which can affect the efficacy of antibiotics. If it must be applied at the same time, it should be separated by more than 2 hours. Sixth, the combination of antibiotics with sulfadiazine: sulfadiazine is one of the commonly used drugs for the treatment of ulcerative colitis. After oral administration, a small portion of sulfadiazine is absorbed in the gastrointestinal tract, while the remaining unabsorbed portion is broken down by intestinal bacteria into sulfapyridine and 5-aminosalicylic acid in the terminal ileum and colon. The mechanism of the drug is mainly through the inhibition of prostaglandin synthesis by 5-aminosalicylic acid. If antibiotics are applied at the same time, the amount of intestinal bacteria will be reduced, which will affect the breakdown of the drug and reduce its efficacy. Therefore, it is not advisable to combine salazosulfadiazine with antibiotics. The 5-aminosalicylic acid preparations applied in recent years, such as Addisha, may not be affected by antibiotics because they function directly without bacterial decomposition. Seven, organophosphorus pesticide poisoning application energy combination: organophosphorus pesticide poisoning is a critical disease of gastroenterology, the onset of the main manifestation of the toxic inhibition of the body cholinesterase acetate acetylcholine accumulation of clinical signs and symptoms. Organophosphorus pesticide poisoning is often accompanied by damage to multiple organs, so energy synergists are often used clinically as an adjunct to treatment. In vivo acetylcholine is synthesized by choline and acetyl coenzyme A under the action of choline acetylase, and intravenous injection of acetyl coenzyme A can aggravate the accumulation of acetylcholine. Acetyl coenzyme A is mainly oxidized through the triglyceride cycle, a process that is inhibited by ATP. ATP supplementation slows down the tris-hydroxylate cycle and increases acetylcholine synthesis. Therefore, it is not advisable to apply energy synergists in the rescue of organophosphorus pesticide poisoning. The combination of cisapride and antidepressants: Irritable bowel syndrome has many kinetic and psychiatric abnormalities, and prokinetic drugs and antidepressant therapy are more commonly used in clinical practice. Cisapride is a full gastrointestinal motility drug that selectively acts on 5-HT4 receptors in the gastrointestinal wall to stimulate the release of acetylcholine from the intestinal interosseous plexus and thus promote gastrointestinal motility. Antidepressants such as promethazine, amitriptyline and doxorubicin are mostly tricyclic compounds, which play an antidepressant role mainly by blocking the reuptake of norepinephrine and 5-hydroxytryptophan. In recent years, the clinical use of 5-hydroxytryptophan reuptake drugs, such as paroxetine and fluoxetine. Cisapride and antidepressants are monoamine oxidase inhibitors, both of which inhibit hepatic cytochrome oxidase P450 isoenzymes. Therefore, the combination of the two drugs enhances the toxicity of the drugs to the liver.