Cimetidine inhibits the secretion of stomach acid and can be used to relieve heartburn, stomach pain, acid reflux, and other symptoms caused by excess stomach acid.Side effects such as weakness, diarrhea, headache, muscle spasms, dizziness, myalgia, hair loss, rash, and gynecomastia can be experienced with the medication. Adults take 1 tablet at a time, twice a day, up to 4 tablets in 24 hours. It takes 4-8 weeks to treat peptic ulcer, reflux esophagitis, etc. The drug its interactions with aluminum hydroxide, diazepam, aminoglycoside antibiotics, theophylline, propranolol, phenytoin sodium, aspirin and other medications, so you should consult with a medical professional before use. It is contraindicated in the following cases: allergy to the drug; pregnant and lactating women; changes in the properties of the drug. Use with caution in the following conditions: systemic lupus erythematosus; severe cardiac and respiratory disorders; hepatic and renal insufficiency; organic encephalopathy; allergies. If you need to use the drug, please strictly follow the instructions of the doctor under the guidance of the medication, do not self-medication.