SMZco is the abbreviation for Compound Sulfamethoxazole, and this medication is also called Cotrimoxazole. Cotrimoxazole belongs to sulfonamide antimicrobial drugs, which is a compound preparation of sulfamethoxazole and methotrexate, belongs to broad-spectrum antimicrobial agents, and has good and strong antibacterial effects against Streptococcus pneumoniae, Escherichia coli, Salmonella spp., gonococcus, and Neisseria meningitidis, and so on. Cotrimoxazole is mainly used for the treatment of urinary tract infections caused by sensitive strains of Escherichia enterica, Klebsiella spp. and Enterobacter spp.; acute exacerbation of adult chronic bronchitis caused by Streptococcus pneumoniae; diarrhea caused by Escherichia coli; and Pneumocystis carinii pneumonia and other diseases. Patients taking Cotrimoxazole may experience adverse reactions such as drug rash, nausea, vomiting, diarrhea, neutropenia or deficiency, anemia, hemoglobinuria, hepatic and renal damage, hyperbilirubinemia. And this product is not suitable for long-term use, high blood concentration will lead to increased incidence of adverse reactions, and even cause bone marrow suppression. It is recommended that patients take the drug under the guidance of a doctor, allergic to the drug, infants less than two months, severe hepatic and renal impairment, with erythrocytic anemia is prohibited. Patients need to check the blood, liver and kidney functions, urine routine and other indicators regularly during the period of taking the drug, in order to prevent the occurrence of serious adverse reactions.