Antidiarrheals

• Antidiarrheal overview


  Three main classes of drugs are used for diarrhea

  absorbent preparations, opiates, and anticholinergics
• Antidiarrheal examples


  Absorbents: Pepto-Bismol, Kaopectate

  Opiates: diphenoxylate-atropine (Lomotil), difenoxin-atropine (Motofen, loperamide (immodium)

  anticholinergics: Alosetron (Lotronex)
• Kaolin


  clay like powder that attracts and holds onto bacteria and thickens the stool
• Pepto-Bismol


  antisecretory effects which causes less secretions in the stool
• Diphenoxylate-atropine


  decreases secretion and slows peristalsis

  is an opiate and can cause opiate like efects
• Loperamide


  slows peristalsis

  reduces fecal volume and increases bulk

  reduces absorption of fluid
• Pharmacotherapeutics of antidiarrheals


  drugs that delay gastric motility are contraindicated in liver and renal impairment due to risk of toxic megacolon

  Atropine is contraindicated in narrow angle glaucoma and down syndrome and children

  Bismuth is contraindicated in children who are recovering from URI

  eluxadoline could cause pancreatitis

  Alosetron is contraindicated in constipation
• Adverse drug reactions antidiarrheals

  constipation

  diphenoxylate-atropine can cause anticholinergic symptoms such as dry mouth, flushing, tachycardia, and urinary retention, dizziness, and drowsiness

  nausea/vomiting
• Use and dosing of antidiarrheals

  Absorbents: taken after each loose stool

  chronic diarrhea with IBS: steroids and sulfasalazine, loperamide

  IBS: loperamide

  Infantile diarrhea: bismuth salicylate 2.5 mL q 4 hours for 2-24 months and 5 mL

  travelers diarrhea: bismuth subsalicylate
• Education of antidiarrheals


  take as prescribed, do not double dose or take extra doses
• Adverse reactions of antidiarrheals

  Constipation

  bismuth can turn tongue and stool gray or black

  diphenoxylate can cause anticholinergic effects

  crofelemer may cause upper respiratory infection
• Lifestyle changes with antidiarrheal


  adding fiber

  wash hands

  fasting to rest the GI tract

  avoid foods that cause diarrhea
• Crofelemer is indicated for patients on antiretroviral therapy
• Anticholinergic antidiarrheals such as atropine/difenoxin are contraindicated in narrow angle glaucoma
• atropine is contraindicated in children, especially those with down-syndrome
• bismuth subsalicylate is contraindicated in patients with a history of asthma and aspirin sensitivity
• pancreatitis is an adverse effect of eluxadoline
• alosetron is contraindicated in patients with hepatic impairment and has a black box warning
• Kaolin/pectin is safe in pregnancy
• Bismuth subsalicylate may increase risk of aspirin toxicity
• diphenoxylate, atropine, and loperamide all have additive or potentiating CNS effects
• Absorbent preparations are commonly used in acute diarrhea
• Children with severe diarrhea need oral rehydrating solutions
• Loperamide is generally given for IBS associated diarrhea
• All patients should be cautioned about rebound constipation when discontinuing medication
• diphenoxylate can cause anticholinergic symptoms such as dr y mouth, tachycardia, and urinary retention
• eluxadoline may cause pancreatitis