Diphenoxylic Acid

Diphenoxylic Acid Uses, Dosage, Side Effects, Food Interaction and all others data.

Diphenoxylic Acid is a 4-phenylpiperidine which is closely related to the opioid analgesic meperidine. Diphenoxylic Acid alone is a USA Schedule I controlled drug, as it may be habit forming. However, it is listed as a Schedule IV controlled drug if combined with atropine, which is added to decrease deliberate misuse. Motofen(R) is a brand mixture which combines atropine sulfate and difenoxin hydrochloride. It is approved by the FDA to treat acute and chronic diarrhea.

Diphenoxylic Acid is an active metabolite of the anti-diarrheal drug, diphenoxylate, which is also used in combination with atropine in the brand mixture Lomotil(R). It works mostly in the periphery and activates opioid receptors in the intestine rather than the central nervous system (CNS). [3] Diphenoxylic Acid is also closely related to loperamide, but unlike loperamide it is still capable of crossing the blood brain barrier to produce weak sedative and analgesic effects. However, the antidiarrheal potency of difenoxin is much greater than its CNS effects, which makes it an attractive alternative to other opioids.

Diphenoxylic Acid acts as a potent antidiarrheal by slowing the movement of the intestines. It also crosses the blood brain barrier to a slight degree to exert weak sedative and analgesic effects.

Diphenoxylic Acid
Uses
Dosage
Side Effect
Precautions
Interactions
Uses during Pregnancy
Uses during Breastfeeding
Accute Overdose
Food Interaction
Half Life
Volume of Distribution
Clearance
Interaction With other Medicine
Contradiction
Storage

Trade Name	Diphenoxylic Acid
Generic	Difenoxin
Difenoxin Other Names	Difenoxin, Difenoxina, Difenoxinum, Diphenoxilic acid, Diphenoxylic acid
Type
Formula	C₂₈H₂₈N₂O₂
Weight	Average: 424.5341 Monoisotopic: 424.21507815
Groups	Approved, Illicit
Therapeutic Class
Manufacturer
Available Country
Last Updated:	September 19, 2023 at 7:00 am

Uses

Diphenoxylic Acid is an antidiarrheal agent used as an adjunct for the management of acute nonspecific diarrhea and acute exacerbations of chronic functional diarrhea.

Motofen(R) is a combination of atropine, an anticholinergic drug, and difenoxin, an antidiarrheal drug. It has been used in many countries for many years as a second line opioid-agonist antidiarrheal, which exists an intermediate between loperamide and paragoric. [2]

Diarrhea which is a result of cyclic or diarrhea predominant Inflammatory Bowel Syndrome may not be treated effectively with difenoxin, diphenoxylate, or loperamide. As such, diarrhea and cramping which does not respond to non-centrally acting derivatives or belladonna derivatives such as atropine are often treated with conservative doses of codeine. In patients with acute ulcerative colitis, as induction of toxic megacolon is possible, and thus use of Motofen(R) is cautioned.

Motofen(R) has been assigned pregnancy category C by the FDA, and is to be used only when the potential benefits outweigh the potential risk to the fetus. The safety of use during lactation is unknown and thus not recommended.

Diphenoxylic Acid is also used to associated treatment for these conditions: Diarrhoea, Acute exacerbations of functional diarrhea

How Diphenoxylic Acid works

Diphenoxylic Acid acts as an antidiarrheal by activating peripheral opioid receptors in the small intestine and thereby inhibiting peristalsis. However, research has suggested that non-opioid receptor pathways exist. This would explain the potent antidiarrheal effects of difenoxin despite only limited opioid action [1].

Food Interaction

Avoid alcohol. Alcohol can enhance the CNS depressant effects of this drug.

Elimination Route

A high percentage of Motofen(R) is absorbed, and absorption occurs rapidly. Peak plasma concentrations are achieved within 40-60 minutes. [Lexicomp, 2013]