Pneumonitis Caused by Metronidazole

To the Editor.— As many as 50% of patients are admitted to the hospital because of adverse drug reactions; up to 18% of hospitalized patients suffer from side effects of drugs, which sometimes may be fatal. 1 Over 20 years, metronidazole has earned a reputation of being remarkably safe, although in recent years doses and duration of treatment have gradually increased, for example, when treating Crohn's disease. 2 Adverse reactions have mostly been mild and reversible, such as nausea, vomiting, fever, urticaria, and metallic taste, but sometimes can be more severe, such as polyneuropathy, mental confusion, convulsions, and leukopenia. Recently, cases of serum sickness and meningitis have been described. We report a case of pneumonitis caused by metronidazole. 2 Report of a Case.— A 42-year-old woman was admitted to the hospital for the first time on Aug 3,1985. She had a known pollen allergy, but no known hypersensitivity to drugs.