Sulfanilamide for HIV is usually taken for the preventive treatment of Pneumocystis pneumonia or toxoplasmosis encephalitis, but it may also be used to treat other bacterial infections. The medication should be used under a doctor’s supervision. Sulfanilamide is a broad-spectrum antibiotic with antibacterial properties. Sulfanilamide can treat other bacterial infections including Streptococcus pneumoniae and Escherichia coli. AIDS patients taking sulfanilamide may experience adverse reactions such as rash, nausea, vomiting, headache, confusion, depression, hematuria, etc. Sulfanilamide should be contraindicated for those who are allergic to SMZ and TMP, pregnant and lactating women, and those with severe liver or kidney impairment. AIDS patients should be guided by a doctor to take sulfanilamide, and should not decide to use the drug by themselves; it is recommended that AIDS patients go to regular hospitals in time.