Medical use - Treatment of Lyme disease - Treatment of chronic prostatitis - Treatment of sinusitis - Treatment of pelvic inflammatory disease - Treatment of rickettsial infections

Antibacterial - Effective against Moraxella catarrhalis - Effective against Brucella melitensis - Effective against Chlamydia pneumoniae - Effective against Mycoplasma pneumoniae - Some strains of Pseudomonas aeruginosa have developed resistance

Antimalarial - Active against erythrocytic stages of Plasmodium falciparum - Not active against gametocytes - Used in the treatment of malaria - Can be used as prophylaxis against malaria - Targeting a plastid organelle, the apicoplast

Side effects - Diarrhea - Nausea - Vomiting - Abdominal pain - Increased risk of sunburn

Commercial use and availability - Patented in 1957 - Came into commercial use in 1967 - Included in the World Health Organization's List of Essential Medicines - Available as a generic medicine - 79th most commonly prescribed medication in the United States in 2020 with over 9 million prescriptions