Adult: Each tab or 5 mL soln contains diphenoxylate HCl 2.5 mg and atropine sulphate 0.025 mg: Initially, 5 mg 4 times daily, may reduce dose to 5 mg daily once satisfactory control is achieved. Max: 20 mg daily. Child: As oral soln: Recommended dose: 2 yr 1.5-3 mL. 3 yr 2-3 mL. 4 yr 2-4 mL. 5 yr 2.5-4.5 mL. 6-8 yr 2.5-5 mL. 9-12 yr 3.5-5 mL. Dose is given 4 times daily.
Patient w/ history of physical dependence, cirrhosis or advanced hepatorenal disease. Hepatic and renal impairment. Childn. Pregnancy and lactation. Not indicated as treatment for diarrhoea associated w/ pseudomembranous colitis or enterotoxin-producing bacteria.
This drug may cause CNS depression, drowsiness, or dizziness, if affected, do not drive or operate machinery.
Monitor for signs of atropism (e.g. dryness of skin and mucous membranes, tachycardia, thirst, flushing), number and consistency of stools. Assess signs of toxicity, fluid and electrolyte loss, hypotension, and resp depression.
Symptoms: Dryness of skin and mucous membrane, flushing, hypothermia, tachycardia, nystagmus, pinpoint pupils, hypotonic reflexes, lethargy, coma, and severe resp depression. Management: Establish patient airway and artificial ventilation may be needed. Employ gastric lavage and admin of slurry of an activated charcoal for conscious patients may be indicated. Administer naloxone to reverse resp depression.
Increased antimuscarinic side effects w/ amantadine, antihistamines, and TCAs. Antagonises the effect of domperidone, metoclopramide, bethanechol, carbachol, cisapride, galantamine, neostigomine, pyridostigmine, and pilocarpine. May potentiate CNS depressant effects of barbiturates and tranquilizers. May precipitate hypertensive crisis when concomitantly used w/ MAOIs. May reduce absorption of ketoconazole. May reduce plasma concentration of levodopa. Increased effect w/ memantine.
May potentiate CNS depressant effect of alcohol.
Description: Diphenoxylate, a synthetic opioid derivative, is an antidiarrhoeal agent acting on smooth muscle of the intestinal tract, inhibiting excessive GI motility and propulsion. Commercial preparations contain subtherapeutic amount of atropine, an antimuscarinic agent, to counteract its abuse. Pharmacokinetics: Absorption: Diphenoxylate: Well absorbed from the GI tract. Bioavailability: Approx 90%. Time to peak plasma concentration: Approx 2 hr. Atropine: Rapidly and well absorbed. Distribution: Diphenoxylate: Enters breast milk. Atropine: Widely distributed throughout the body; crosses the blood brain barrier and enters breast milk. Plasma protein binding: 14-22%. Metabolism: Diphenoxylate: Rapidly and extensively metabolised in the liver via ester hydrolysis to diphenoxylic acid, an active metabolite, and hydroxydiphenoxylic acid. Atropine: Metabolised in the liver via enzymatic hydrolysis. Excretion: Diphenoxylate: Mainly via faeces (49% as unchanged drug and metabolites) and urine (approx 14% as unchanged drug). Elimination half-life: 2.5 hr. Atropine: Via urine (13-50% as unchanged drug and metabolites).
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