Recommended Dosage of Sennakot (Senna)
The recommended dosage of Sennakot (senna) for adults and children 12 years and older is 2-3 teaspoons (10-15 mL) once daily, with a maximum dosage of 3 teaspoons (15 mL) twice daily. 1
Adult Dosing Guidelines
- For adults and children 12 years and older: 2-3 teaspoons (10-15 mL) once daily, preferably at bedtime 1
- Maximum dosage: 3 teaspoons (15 mL) twice daily 1
- Most commercially available senna products contain 8-9 mg of sennosides per tablet, which is significantly lower than the 1g dose used in clinical trials 2
- The American Gastroenterological Association-American College of Gastroenterology recommends starting at a lower dose and increasing if there is no response 2
Pediatric Dosing Guidelines
- Children 6-12 years: 1-1½ teaspoons (5-7.5 mL) once daily, maximum 1½ teaspoons (7.5 mL) twice daily 1
- Children 2-6 years: ½-¾ teaspoon (2.5-3.75 mL) once daily, maximum ¾ teaspoon (3.75 mL) once daily 1
- Children under 2 years: Consult a doctor 1
Administration Recommendations
- Take at bedtime for optimal effect 1
- Shake the liquid formulation well before using 1
- Do not exceed the maximum recommended dose 1
- Consider taking with food to minimize gastrointestinal side effects 2
Mechanism of Action
- Senna is a natural derivative of the senna plant 2
- Sennosides A and B are metabolized by gut microbiota to active metabolites (rheinanthrone and rhein) 2, 3
- These active metabolites stimulate prostaglandin E2 production and chloride ion secretion, leading to increased colonic peristalsis and water content 2, 3
- Over 90% of sennosides and their metabolites are excreted in feces 2, 3
Efficacy
- Senna significantly increases complete spontaneous bowel movements (CSBMs) per week compared to placebo 2
- It also improves quality-of-life scores in patients with chronic constipation 2
- Senna is effective in reducing colonic transit time from 39±4 hours to 17±3 hours 4
- When combined with fiber, senna provides better relief of constipation than fiber alone 5
Potential Side Effects and Precautions
- Common side effects include abdominal pain, cramping, and diarrhea, particularly at higher doses 2, 6
- In clinical trials, 83% of participants reduced their daily dose due to side effects 2
- Perineal blistering is a rare side effect, occurring in approximately 2.2% of patients, typically associated with higher doses (60mg/day) and prolonged skin contact with stool 6
- Senna is contraindicated in individuals with ileus, intestinal obstruction, severe dehydration, or acute inflammatory conditions in the bowel 2
Special Populations
- Senna is generally safe for use in patients with chronic kidney disease as over 90% of sennosides and their metabolites are excreted in feces 3
- For geriatric patients, senna combined with bulk laxative has been shown to be more effective than lactulose in treating chronic constipation 7
- Senna is not recommended during pregnancy due to limited safety data 2
Place in Therapy
- The American Gastroenterological Association-American College of Gastroenterology conditionally recommends senna for chronic constipation treatment (conditional recommendation, low certainty evidence) 2, 8
- Senna is typically considered after first-line agents like polyethylene glycol (PEG) 8
- It can be used as a standalone treatment or in combination with fiber supplements for enhanced efficacy 4, 5