Benzathine penicillin should be benzylpenicillin for injection, which needs to be given intramuscularly and can be injected in the buttocks. Benzathine penicillin for injection is a white crystalline powder, western drug, injection. It can be injected intramuscularly and does not have to be limited to the buttocks, but can also be injected in the upper arm and other areas. It is mainly used as long-term prophylaxis for patients with rheumatic fever and rheumatic heart disease; for the treatment of mild-to-moderate infections caused by streptococcus, staphylococcus, and other sensitive bacteria, such as pneumonia, tonsillitis, and gonorrhea; and for the treatment of all stages of syphilis. Adverse reactions: there may be allergic reactions, such as skin rash, asthma attacks, etc., serious cases cause shock. Contraindications: It is forbidden for those who are allergic to this product. Injection matters: penicillin skin test should be carried out before using the drug, with asthma, urticaria and other allergic diseases should be used with caution. If there is any discomfort after the injection of this product, consult a physician in time.