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Combination of
Diphenoxylate mu opiate receptor agonist
Atropine muscarinic acetylcholine receptors antagonist
CAS number  ?
ATC code  ?
PubChem  ?
Therapeutic considerations
Pregnancy cat.


Legal status

POM(UK) Schedule V(US)

Routes Oral

Lomotil is the trade name of a popular oral anti-diarrheal drug in the United States, manufactured by Pfizer. Its UK BAN generic name is Co-phenotrope.

Its active ingredients are diphenoxylate and atropine. Diphenoxylate is anti-diarrheal and atropine is anticholinergic. Diphenoxylate is chemically related to the narcotic drug meperidine. A subtherapeutic amount of atropine sulfate is present to discourage deliberate overdosage. Atropine has no anti-diarrheal properties, but will cause tachycardia when overused. The medication diphenoxylate works by slowing down the movement of the intestines.

The inactive ingredients of Lomotil (as a liquid - it comes in pill form as well) are cherry flavor, citric acid, ethyl alcohol 15%, FD&C Yellow No. 6, glycerin, sodium phosphate, sorbitol, and water.

Other trade names for the same therapeutic combination are Lofene, Logen, Lomanate and Lonox, among others. In other countries, Lomotil may have other names.

In the United States, Lomotil (Diphenoxylate HCl and atropine sulfate) is classified as a Schedule V controlled substance by federal law, and is available only for a medical purpose.[1]



Absolute contraindications for Lomotil are:

  • Allergy to diphenoxylate or atropine
  • Presence of jaundice
  • Diarrhea associated with pseudomembranous enterocolitis, diarrhea caused by antibiotic treatment, or diarrhea caused by enterotoxin-producing bacteria.


Interactions with other drugs:

Diarrhea that is caused by some antibiotics such as cefaclor, erythromycin or tetracycline can worsen with Lomotil.


The drug combination is generally safe in short-term use and with recommended dosage. Long-term use may present problems of mild drug dependency. The dosage should be reduced after 48 h.

Lomotil may cause several side-effects, such as dry mouth, headache, constipation and blurred vision. Since it may cause also drowsiness or dizziness, Lomotil should not be used by motorists, operators of hazardous machinery, etc. It is not recommended for children under two years of age. In rare cases lomotil may cause paresthesia.


Lomotil may cause serious health problems when overdosed. Signs and symptoms of adverse effects may include any or several of the following: convulsions, respiratory depression (slow or stopped breathing), dilated eye pupils, nystagmus (rapid side-to-side eye movements), erythema (flushed skin), gastrointestinal constipation, nausea, vomiting, paralytic ileus, tachycardia (rapid pulse), drowsiness, coma and hallucinations. Symptoms of toxicity may take up to 12 hours to appear.

Treatment of Lomotil overdose must be initiated immediately after diagnosis and may include the following: emesis (induced vomiting), gastric lavage, ingestion of activated charcoal, laxative and a counteracting medication (narcotic antagonist).

Prompt and thorough treatment of overdose leads to a favorable outcome. After a narcotic antagonist is given, recovery is usually within 24 to 48 hours. Children are at risk of a very poor outcome and must be kept for observation.


  1. ^


  • Lomotil overdose. MedlinePlus Medical Encyclopedia. Public domain.
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Lomotil". A list of authors is available in Wikipedia.
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