Antihistamines currently in common use in China This article introduces you, the consultant, to antihistamines currently in common use in China for the treatment of allergic dermatoses, scratchy dermatoses and other allergic diseases, and any questions you may have about their use. Please read the instructions or ask the doctor who gave you the medicine, this article is for reference only. Promethazine (antiamine seeking, fenagan): This product is both a homologue of chlorpromazine and has the basic structure of a receptor blocker, so it has an antihistamine effect and a stabilizing, antiemetic, hypothermic effect. It also has obvious central inhibition, anti-dizziness, anti-cholinergic and anti-5-hydroxytryptamine effects. The manifestations of overdose include angina pectoris, arrhythmia, palpitations, diarrhea, vomiting, tremor, excitement, headache, restlessness, insomnia, excessive sweating, flushing, weight loss, and skeletal muscle spasm, which usually disappear after reducing the dosage or stopping the drug for several days. It is contraindicated in myasthenia gravis, closed-angle glaucoma, and prostatic hypertrophy. Contraindicated in patients with hypersensitivity to this product and excipients. Contraindicated in newborns and premature infants. Common adverse reactions include drowsiness, dizziness, dry mouth, skin photosensitivity, jaundice and extrapyramidal symptoms have also been reported. Leukopenia and granulocyte deficiency are rare, and side effects such as tachycardia or bradycardia, transient mild increase in blood pressure, and occasionally hypotension are common with injectable administration. Convulsions followed by central depression can be caused by excessive doses. The following conditions should be used with caution: hypertension, prostate hypertrophy, pyloric or duodenal obstruction, closed-angle glaucoma, respiratory diseases, sputum that is thick and difficult to cough up, epilepsy patients. Forbidden for newborns and premature infants. Local irritation during injection, avoid leakage of drug out of blood vessels when injecting quietly.