ヒスタミンH2受容体拮抗薬の用い方のコツ

How to Use the Histamine H2-Receptor Antagonist Properly for Treatment of Peptic Ulcer

要旨　H₂レセプター拮抗薬は強力な胃酸分泌抑制作用を持ち，従来の抗潰瘍剤に比して消化性潰瘍の治癒を促進する．しかし，このH₂レセプター拮抗薬も万能ではなく，実際の潰瘍治療に際しては潰瘍の自然史や消化管の病態生理を考慮して薬剤を決定するのが理想的である．十二指腸潰瘍は高齢者においても酸分泌が高く，しかも酸分泌が高いほど再発も起こりやすい傾向がある．したがってH₂レセプター拮抗薬の適応としては十二指腸潰瘍が最適である．一方，胃体部の潰瘍ではH₂レセプター拮抗薬のほかに組織修復促進作用や胃粘膜保護作用のある薬剤との併用が望まれる．潰瘍の治療では患者の生活態度も大きな影響を持つが，最近，治療中の喫煙が薬剤の効果を減少させ，治癒を遅らせるとの報告が幾つかみられる．潰瘍の自然史の特徴の1つは治癒と再発を繰り返すことであり，潰瘍治療の最終目標は自然史を変化させて，治癒と再発の鎖を断ち切ることにある．現在まで，H₂レセプター拮抗薬が自然史に変化をもたらし，潰瘍を永久治癒に導くとの報告はない．

　Histamine H₂-receptor antagonist, a new anti-ulcer drug, produces more rapid healing of peptic ulcer through its strong inhibition of gastric acid secretion than conventional anti-ulcer drugs. This new drug, however, is not almighty in ulcer treatment. Ideally, the selection of anti-ulcer drug must depend on the natural history of and the pathophysiological changes by peptic ulcer.

　Gastric acid secretion is high in duodenal ulcer even when a patient is old, and the higher the acid secretion, the more frequently duodenal ulcer relapses. This means that duodenal ulcer is most suited for treatment with H₂ receptor antagonist. On the other hand, as for gastric ulcer on the body of the stomach which is mainly found in older patients, H₂-receptor antagonist is better taken with some other drugs, accelerating the mucosal defensive mechanism in the stomach.

　It is well known that the patient's life style has a marked influence on the ulcer healing. Recently, there have been some reports that smoking habit during the treatment with H₂-receptor antagonist reduces the effect of drug followed by the lowered rate of ulcer healing.

　A feature in the natural history of peptic ulcer is that this disease repeats relapse at various intervals. The final goal in ulcer treatment is the interruption of the cycle of relapse by changing the natural history. At present, however, there has been no report that H₂-receptor antagonist can change the natural history and produce the permanent healing of peptic ulcer.