Diphenoxylate

Oral
Acute diarrhoea

Oral
Chronic diarrhoea

May be taken with or without food.

Infants and children <4 yr. Jaundice, intestinal obstruction. Diarrhoea associated with pseudomembranous colitis or enterotoxin-producing bacteria.

Hepatic dysfunction, inflammatory bowel disease. Pregnancy, lactation; young children.

GI effects; headache, drowsiness, dizziness, restlessness, euphoria, depression, numbness of the extremities; hypersensitivity reactions, swelling of the gums.

PO: C (FDA Pregnancy Category C applies only in combination w/ atropine.)

Symptoms: Atropinism may persist for 2-3 hr (e.g. high fever, generalised flushing, and tachypnoea). Drowsiness, miosis, hypotonia, loss of tendon reflexes, nystagmus, and seizures followed by respiratory depression and total apnoea may manifest 12-30 hr after drug ingestion. Treatment: empty stomach by emesis or by gastric lavage. Gastric lavage may be effective even after several hr due to decreased GI motility and pylorospasm. Treatment is supportive and symptomatic and monitor closely for 48 hr. Naloxone may be useful in the treatment of severe respiratory depression.

Potentiates effects of other CNS depressants (alcohol, barbiturates) and some anxiolytics.
Potentially Fatal: Theoretical hypertensive crisis with MAOIs.

Description:
Mechanism of Action: Diphenoxylate is a synthetic derivative of pethidine with little or no analgesic activity. It reduces intestinal motility and excessive GI propulsion by acting on the smooth muscle of the intestinal tract.
Onset: 45 min to 1 hr.
Duration: 3-4 hr.
Pharmacokinetics:
Absorption: Well absorbed from the GI tract.
Distribution: May distribute into breast milk.
Metabolism: Rapidly and extensively metabolised in the liver.
Excretion: Excreted mainly as metabolites and their conjugates in the faeces.

Antidiarrheals