Comparative Pharmacology
Head-to-head clinical analysis: DIPHENOXYLATE HYDROCHLORIDE W ATROPINE SULFATE versus LOMOTIL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DIPHENOXYLATE HYDROCHLORIDE W ATROPINE SULFATE versus LOMOTIL.
DIPHENOXYLATE HYDROCHLORIDE W/ ATROPINE SULFATE vs LOMOTIL
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Diphenoxylate acts as an opioid agonist on mu-opioid receptors in the gastrointestinal tract, reducing peristalsis and increasing intestinal transit time. Atropine sulfate is added at subtherapeutic doses to deter abuse by causing unpleasant anticholinergic effects at high doses.
Diphenoxylate is a meperidine congener that acts as an opioid receptor agonist, inhibiting gastrointestinal motility and prolonging transit time; atropine is added to discourage abuse at high doses.
2.5-5 mg (diphenoxylate) orally 4 times daily until diarrhea controlled; maximum 20 mg/day (diphenoxylate).
Adults: 2 tablets (2.5 mg diphenoxylate/0.025 mg atropine) orally four times daily until control of diarrhea is achieved; maintenance dose is 2 tablets once or twice daily. Maximum dose: 8 tablets (20 mg diphenoxylate) per day.
None Documented
None Documented
Diphenoxylate: terminal half-life of 2.9-5.8 hours (active metabolite difenoxin: 12-14 hours). Atropine: terminal half-life of 2-4 hours. Clinical context: The long half-life of difenoxin contributes to sustained antidiarrheal effect.
Diphenoxylate: 2.5-3.5 hours; Difenoxin (active metabolite): 12-24 hours. Clinically, antidiarrheal effect is prolonged due to metabolite accumulation.
Diphenoxylate is excreted primarily in feces (via biliary elimination) as the active metabolite difenoxin and its conjugates; approximately 14% is excreted renally as unchanged drug and metabolites. Atropine is excreted renally (30-50% unchanged) and partially in feces.
Primarily renal (50-70% as metabolites, <5% unchanged) and fecal (30-50% via biliary excretion).
Category C
Category C
Antidiarrheal
Antidiarrheal