Dosing and uses of Mytesi (crofelemer)
Adult dosage forms and strengths
tablet, delayed-release
- 125mg
Noninfectious Diarrhea
Antidiarrheal indicated for noninfectious diarrhea in patients with HIV/AIDS on antiretroviral therapy
125 mg PO BId
Pediatric dosage forms and strengths
<18 years: Safety and efficacy not established
Mytesi (crofelemer) adverse (side) effects
1-10%
Upper respiratory tract infection (5.7%)
Bronchitis (3.9%)
Cough (3.5%)
Flatulence (3.1%)
Increased bilirubin (3.1%)
Nausea (2.6%)
Back pain (2.6%)
Arthralgia (2.6%)
Urinary tract infection (2.2%)
Nasopharyngitis (2.2%)
Musculoskeletal pain (2.2%)
Hemorrhoids (2.2%)
Giardiasis (2.2%)
Anxiety (2.2%)
Increased ALT (2.2%)
Abdominal distension (2.2%)
Warnings
Contraindications
None
Cautions
Not indicated for infectious diarrhea; before initiating, rule out infectious etiologies of diarrhea
If initiated based on a presumptive diagnosis of noninfectious diarrhea, then there is a risk that patients with infectious etiologies will not receive the appropriate treatments, and their disease may worsen
In vitro studies have shown that crofelemer has the potential to inhibit CYP3A4 and transporters MRP2 and OATP1A2 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed
Pregnancy and lactation
Pregnancy category: C Lactation: Unknown whether distributed in human breast milk
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Mytesi (crofelemer)
Mechanism of action
Botanical substance derived from the red latex of Croton lechleri Müll. Arg. (Euphorbiaceae)
Inhibitor of both cAMP-stimulated cystic fibrosis transmembrane conductance regulator (CFTR) chloride ion (Cl) channel, and the calcium-activated Cl channels (CaCC) at the luminal membrane of enterocytes; CFTR Cl channel and CaCC regulate Cl and fluid secretion by intestinal epithelial cells
Acts by blocking Cl secretion and accompanying high volume water loss in diarrhea, normalizing the flow of Cl and water in the GI tract
Pharmacokinetics
Absorption: Minimal; below the level of quantitation (ie, 50 ng/mL)
Distribution: Not determined
Metabolism: No metabolites identified
Elimination: Not identified
Administration
Oral Administration
May take with or without food
Swallow tablet whole; do not crush, chew, or dissolve
