23.2 : 下痢型過敏性腸症候群の治療薬

Diarrhea-predominant irritable bowel syndrome or IBS-D, is characterized by chronic abdominal pain and diarrhea.

Effective IBS-D management involves dietary modifications, stress control management, and drug therapy.

Central to treatment is alosetron and eluxadoline.

Alosetron interacts with 5-HT₃ receptors, pivotal for gut motility, pain, and nausea. By inhibiting these receptors, it eases abdominal pain and reduces gut contractions. This slows colonic stool transit and boosts intestinal fluid absorption, curbing diarrhea.

Adverse effects encompass constipation, ischemic colitis, vomiting, and hemorrhoids.

Eluxadoline, a mixed opioid-receptor agonist and antagonist affects the enteric neurons that impact gut motility and visceral sensations of pain and nausea.

Despite limited oral bioavailability, it effectively reduces intestinal transit speed and enhances stool consistency.

Notable side effects comprise constipation, nausea, and pancreatitis, with a potential risk of addiction.