Senna — Supplements
Stimulant laxative containing sennosides for short-term management of acute constipation.
Overview
Senna (Cassia angustifolia/acutifolia) contains anthraquinone glycosides (sennosides A and B) that are prodrugs activated by colonic bacteria. The active metabolite rhein anthrone stimulates submucosal nerve plexuses (Auerbach's and Meissner's) and inhibits water and electrolyte absorption, producing a cathartic effect within 6-12 hours. Senna is one of the most widely used OTC laxatives and is included in WHO's List of Essential Medicines. Clinical evidence strongly supports its efficacy for acute constipation, but chronic use is discouraged.
Indications
- Acute constipation relief
- Pre-procedural bowel preparation
- Opioid-induced constipation (short-term)
Mechanism of Action
Colonic bacteria cleave sennoside glycosides to release active rhein anthrone aglycone
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| Senna (Sennosides) | 15 mg sennosides | Once at bedtime | Short-term only (< 1 week); expect bowel movement in 6-12 hours |
Safety & Contraindications
- Short-term use only (< 1 week); chronic use can cause laxative dependency
- May cause abdominal cramping, diarrhea, and electrolyte imbalances
- Chronic use associated with melanosis coli (harmless but concerning appearance)
- Contraindicated in bowel obstruction, acute inflammatory bowel disease, and dehydration
- May interact with digoxin due to potassium depletion