In cases without a history of gastrointestinal or cardiac disease, acute odynophagia prompts the tentative diagnosis of drug-induced esophageal ulcer. Possible causes are tetracycline, clindamycin, emepronium bromide, potassium chloride, etc. Other diseases such as carcinoma can be ruled out by endoscopy and biopsy. To avoid such esophageal lesions drugs should be taken with sufficient fluid and not immediately before bedrest.