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
Adverse 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%)
Mechanism 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