II. Indications

III. Contraindications

  1. Clostridioides difficile
  2. Dysentery (toxigenic Diarrhea)
  3. Child under age 6 years
    1. Risk of respiratory depression (anoxic brain injury and death has occurred)
  4. Down Syndrome (risk of Atropine toxicity, even at low dose)
  5. Elderly (relative contraindication, risk of Atropine toxicity)

IV. Mechanism

  1. Diphenoxylate is typically combined with Atropine (Lomotil) for use as an antidiarrheal
  2. Diphenoxylate is a peripherally acting Opioid acting at gastrointestinal Opioid receptors
    1. Piperidine derivative similar in structure to Meperidine
    2. No significant central activity or Analgesic effect (retained in Gastrointestinal Tract due to insolubility)

V. Preparations

  1. Diphenoxylate/Atropine Tablets (2.5 mg/0.025 mg tablet)
  2. Diphenoxylate/Atropine Solution (2.5 mg/0.025 mg per 5 ml)

VI. Dosing: Acute Diarrhea

  1. Adult
    1. Take 2 tabs (or 10 ml) orally up to 4 times daily as needed
  2. Child
    1. Give 0.3 to 0.4 mg Diphenoxylate per kg per day in 4 divided doses
      1. Age 9 to 12 years (weight 23 to 55 kg): 3.5 to 5 ml orally 4 times daily
      2. Age 6 to 8 years (weight 17 to 32 kg): 2.5 to 5 ml orally 4 times daily
    2. Maximum 20 mg Diphenoxylate per day

VII. Safety

  1. Pregnancy Category C
  2. Safe in Lactation

VIII. Drug Interactions

  1. CNS Depressants
    1. Diphenoxylate with Atropine may potentiate CNS Depressant effect
  2. MAO Inhibitors
    1. Hypertension risk
  3. Anticholinergic Medications
    1. Increased ileus risk

X. References

  1. Hamilton (2020) Tarascon Pocket Pharmacopoeia
  2. Olson (2020) Clinical Pharmacology, Medmaster Miami, p. 96

Images: Related links to external sites (from Bing)

Related Studies

Cost: Medications

diphenoxylate (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing)
DIPHENOXYLATE-ATROPINE 2.5-0.025 MG TABLET Generic $0.18 each

Ontology: Diphenoxylate (C0012525)

Definition (NCI) A piperidine derivate, chemically related to narcotic meperidine with antidiarrheal activity and devoid of central nervous system (CNS) activity. Diphenoxylate acts on opioid receptors in the gastrointestinal tract, thereby decreasing gastrointestinal motility and causing constipation or preventing diarrhea.
Definition (MSH) A MEPERIDINE congener used as an antidiarrheal, usually in combination with ATROPINE. At high doses, it acts like morphine. Its unesterified metabolite difenoxin has similar properties and is used similarly. It has little or no analgesic activity.
Concepts Pharmacologic Substance (T121) , Organic Chemical (T109)
MSH D004157
SnomedCT 440585000, 317360000, 15052009
LNC LP18090-8, MTHU003372
English Diphenoxylate, 4-Piperidinecarboxylic acid, 1-(3-cyano-3,3-diphenylpropyl)-4-phenyl-, ethyl ester, Diphenoxylate (product), Diphenoxylate [Chemical/Ingredient], DIPHENOXYLATE, diphenoxylate, Diphenoxylate (substance), Diphenoxylate [dup] (substance)
Swedish Difenoxylat
Czech difenoxylát
Finnish Difenoksylaatti
Russian DIFENOKSILAT, ДИФЕНОКСИЛАТ
Japanese ジフェノキシラート
Spanish difenoxilato (producto), difenoxilato (sustancia), difenoxilato, Difenoxilato
Polish Difenoksylat
French Diphénoxylate
German Diphenoxylat
Italian Difenossilato
Portuguese Difenoxilato

Ontology: Lomotil (C0065164)

Concepts Organic Chemical (T109) , Pharmacologic Substance (T121)
MSH C002534
English Lomotil, lomotil