Tenapanor

Indications

Tenapanor is used for: Irritable Bowel Syndrome with Constipation

Adult Dose

Irritable Bowel Syndrome with Constipation Indicated for irritable bowel syndrome with constipation (IBS-C) in adults 50 mg PO BID immediately before breakfast and dinner Hepatic impairment: No dose adjustments required

Child Dose

<18 years: Safety and efficacy not established

Renal Dose

Renal impairment: No dose adjustments required

Administration

Take immediately before breakfast or the first meal of the day and immediately before dinner

Contra Indications

Children aged <6 years owing to risk of serious dehydration Known or suspected mechanical GI obstruction

Precautions

Diarrhea may occur; if severe, suspend dosing and rehydrate patient Contraindicated in children aged <6 yr; avoid use in children aged 6-12 yr owing to risk of dehydration in young children

Pregnancy-Lactation

Pregnancy Tenapanor is minimally absorbed systemically, with plasma concentrations below the limit of quantification Maternal use is not expected to result in fetal drug exposure Lactation Data are not available regarding the presence in either human or animal milk, its effects on milk production, or its effects on the breastfed infant The minimal systemic absorption of tenapanor will not result in a clinically relevant exposure to breastfed infants

Interactions

Side Effects

Side effects of Tenapanor : >10% Diarrhea (15-16%) 1-10% Abdominal distension (2-3%) Flatulence (3%) Severe diarrhea (2.5%) Dizziness (2%) Rectal bleeding (<2%) Abnormal GI sounds (<2%)

Mode of Action

Tenapanor is a locally acting inhibitor of the sodium/hydrogen exchanger 3 (NHE3), an antiporter, also known as a countertransporter, on the apical surface of the small intestine and colon primarily responsible for absorption of dietary sodium In vitro and animal studies indicate its major metabolite, M1, is not active against NHE3 NHE3 inhibition reduces sodium absorption from the small intestine and colon, resulting in an increase in water secretion into the intestinal lumen, which accelerates intestinal transit time and results in a softer stool consistency May decrease abdominal pain by decreasing visceral hypersensitivity; shown to reduce visceral hyperalgesia and to normalize colonic neural excitability in animal models