Sulfadoxin is primarily used as a long-acting sulfonamide antibiotic in the treatment of various bacterial infections, such as urinary tract infections, respiratory tract infections, and gastrointestinal infections. It inhibits bacterial growth by interfering with folic acid synthesis, which is essential for bacterial replication. It is often employed in combination with other drugs, such as pyrimethamine, to enhance its efficacy, particularly in the management of malaria caused by Plasmodium falciparum. This combination therapy is effective in regions where resistance to other antimalarial drugs is prevalent. Additionally, sulfadoxin is utilized in veterinary medicine to treat infections in livestock, contributing to animal health and productivity. Its long half-life allows for less frequent dosing, making it a practical option in both human and animal healthcare. However, its use is carefully monitored due to the potential for adverse effects and the development of drug resistance.