Mytesi (crofelemer)

Crofelemer, an oligomeric proanthocyanidin mixture derived from the red latex of the Croton lechleri tree, is an antisecretory antidiarrhea agent.

Crofelemer, a botanical drug product, is derived from the red latex of Croton lechleri Mull. Arg, a tree found in the western Amazonian region of South America. The botanical raw material from the tree has been called dragon's blood (sangre de drago) or tree's blood (sangre de grado).

The drug preparation (crofelemer) is an oligomeric proanthocyanidin mixture consisting principally of catechin, epicatechin, gallocatechin, and epigallocatechin monomer units linked in a random sequence.

The exact mechanism of action of crofelemer in the treatment of noninfectious diarrhea has not been fully elucidated. Crofelemer appears to be an inhibitor of both the cyclic adenosine-monophosphate (cAMP)-stimulated cystic fibrosis transmembrane conductance regulator (CFTR) chloride ion channel and the calcium-activated chloride channel (CaCC) at the luminal membrane of enterocytes. The CFTR chloride channel and CaCC regulate chloride and fluid secretion by intestinal epithelial cells, and activation of these channels may increase chloride and fluid secretions into the GI tract and contribute to secretory diarrhea.

Because crofelemer inhibits these chloride channels, chloride secretion and accompanying high volume water loss are decreased resulting in normalization of chloride and water flow in the GI tract, decreased stool weight and frequency, and symptomatic relief of diarrhea. Diarrhea frequently occurs in patients with human immunodeficiency virus (HIV) infection and can be categorized as infectious (e.g., caused by opportunistic pathogens) or noninfectious (e.g., related to antiretroviral therapy, HIV enteropathy). Some noninfectious causes of diarrhea may involve secretory mechanisms.

Crofelemer acts locally in the GI tract. Systemic absorption of crofelemer is minimal following oral administration of the drug in healthy or HIV-infected individuals. In healthy individuals, administration of crofelemer with a high-fat meal did not increase systemic exposure of the drug; therefore, crofelemer may be administered without regard to meals.

Because plasma concentrations of crofelemer generally have been undetectable following oral administration, certain pharmacokinetic parameters (e.g., area under the plasma concentration-time curve (AUC), peak plasma concentration, half-life, distribution, elimination route) have not been established. Metabolites of crofelemer have not been identified in healthy or HIV-infected individuals.

USES: Crofelemer is used to relieve symptoms of diarrhea in HIV/AIDS patients who are taking medicines to treat HIV infection. This medication may reduce the number of watery stools you have and help you better tolerate your HIV medications. It works by preventing water and minerals from entering into the intestines, causing the stools to be more solid.

Crofelemer should not be used to treat diarrhea caused by infections.

Generic name: crofelemer
Pronunciation: (kroe-FEL-e-mer)
Drug class: Antidiarrheal - Gastrointestinal Chloride Channel Inhibitors
Therapeutic class: Gastrointestinal Therapy Agents

The following indications are listed for Mytesi:

• Diarrhea From Hiv

Also known as: Diarrhea Associated With Hiv Infection, Diarrhea With Human Immunodeficiency Virus Infection, Human Immunodeficiency Virus Enteropathy.