アンピシリン起因性出血性大腸炎の4例

Four Cases of Ampicillin-Associated Colitis

　最近の抗生物質の開発は目覚ましく，各種感染症に対してその利するところ大なるものがあるが，一方では当初予想されなかった種々の副作用が報告されつつある．消化管に対する副作用として良く知られているものにリンコマイシン，クリンダマイシンなどによる偽膜性大腸炎があるが，最近アンピシリンおよびその誘導体に起因すると考えられる血便が散見される¹⁾．われわれも同様の症例を4例経験したので報告する．

　Four famale patients with ampicillin-associated colitis are presented. They were treated with ampicillin for their relevant medical problems which included bronchitis and hordeolum. The dose of ampicillin given varied from 750 to 1,500 mg daily for a period of 5 to 8 days of oral administration. They developed abdominal cramps and watery diarrhea, subsequently followed by bloody diarrhea, during a course of oral ampicillin therapy. Immediate cessation of the antibiotic resulted in a favorable recovery. Colonoscopic examination performed at active stage of the illness showed inflamed colonic mucosa with tiny mucosal hemorrhages and shallow erosions. Resolution way almost complete on follow-up colonoscopy. Barium enema examination performed at active stage showed obliteration of the haustra and narrowing of involved segment of the colon. Numerous small nodules resembling lymphoid hyperplasia of the colon were demonstrated at convalescent stage.

　All the patients investigated here had allergic diathesis, i.e. drug-induced exanthema (3 patients) and allergic rhinitis (1 patient). Hence, it seemed reasonable to suggest that hypersensitivity to the causative antibiotic might be responsible for the development of ampicillin-associated colitis.