What is the recommended dosing for Senekot (senna) in adults and children for the treatment of constipation?

Senekot (Senna) Dosing for Constipation

For adults with constipation, the recommended starting dose of senna is 8.6-17.2 mg (1-2 tablets) once daily, preferably at bedtime, with a maximum dose of 34.4 mg (4 tablets) twice daily. 1, 2

Adult Dosing Algorithm

1. Initial dosing:

   • 8.6-17.2 mg (1-2 tablets) once daily at bedtime
   • OR 2-3 teaspoons (10-15 mL) of liquid preparation once daily at bedtime 2

2. Titration approach:

   • Start at lower dose and increase if no response
   • Titrate based on symptom response and side effects 1

3. Maximum dosing:

   • Up to 34.4 mg (4 tablets) twice daily
   • OR 3 teaspoons (15 mL) of liquid preparation twice daily 2

4. Duration of treatment:

   • Clinical trials typically used 4-week treatment periods
   • Longer-term use is probably appropriate, but more data needed on tolerance and side effects 3

Pediatric Dosing

Age	Usual Dose	Maximum Dose
6-12 years	1-1½ teaspoons (5-7.5 mL) once daily	1½ teaspoons (7.5 mL) twice daily
2-6 years	½-¾ teaspoon (2.5-3.75 mL) once daily	¾ teaspoon (3.75 mL) once daily
Under 2 years	Consult a doctor	Consult a doctor

2

Efficacy and Mechanism of Action

Senna works by:

• Stimulating prostaglandin E2 production
• Promoting chloride ion secretion
• Increasing colonic peristalsis
• Altering luminal water content 1

The American Gastroenterological Association suggests senna as an effective treatment for chronic idiopathic constipation with a conditional recommendation (low certainty of evidence) 3.

Side Effects and Precautions

Common side effects include:

• Abdominal pain and cramping (more common with higher doses)
• Diarrhea
• Nausea 3, 1

Important precautions:

• Higher doses (>60 mg/day) have been associated with perineal blistering in children, particularly with nighttime accidents and prolonged stool-to-skin contact 4
• Antibiotics may decrease senna efficacy by affecting colonic bacteria that produce active metabolites 1
• Not generally recommended during pregnancy due to potential weak genotoxic effects observed in animal studies 1

Clinical Pearls

• Shake liquid preparations well before using 2
• Take at bedtime for optimal effect 1, 2
• Consider as first-line therapy due to efficacy, over-the-counter availability, and low cost 1
• May be particularly effective for opioid-induced constipation 1
• Can be used as occasional rescue therapy or in combination with other constipation treatments 3
• No strong evidence of tolerance development with long-term use 4

For chronic idiopathic constipation, the American Gastroenterological Association recommends starting at a lower dose and increasing if no response occurs, while monitoring for abdominal pain and cramping that may occur with higher doses 3.