Sennosides (Senokot)
Stimulant laxative (anthraquinone)
Sennosides (Senokot)
Forms and strengths
Form: TabletStrength: 8.6 mg, 17.2 mg (standardized senna concentrate)
References
Indication
- Sennosides are used for short-term relief of occasional constipation.
- They are commonly used as a scheduled stimulant laxative alongside an osmotic laxative in patients on chronic opioid therapy, where long-term use may be necessary.
- Used as a bowel-prep adjunct in some pre-procedure regimens.
Pregnancy
- Short-term use of sennosides is considered acceptable in pregnancy when needed, generally as a second step after nonpharmacologic measures and bulk-forming agents.
Breastfeeding
- Sennosides are acceptable to use during breastfeeding; minimal amounts of the active metabolite are excreted into breast milk. Stimulant laxatives are recommended for short-term use only, in pregnancy or breastfeeding.
Geriatrics
- Widely used in older adults; monitor for electrolyte disturbances and increased sensitivity to cramping with chronic or excessive use.
Pediatrics
- Can be used in children 2 years of age and older at a reduced, product-specific dose; consult a healthcare provider before use in young children.
Dosage & Administration
- Usual adult dose: 8.6 to 32.4 mg (1 to 4 tablets of the 8.6 mg strength) PO once daily or at bedtime, up to a maximum of approximately 34.4 to 51.6 mg/day depending on the product — follow the specific product's maximum daily dose.
- Onset of effect is typically 6 to 12 hours, so bedtime dosing is common to produce a morning bowel movement.
- Usually intended for short-term use, but long-term use may be necessary and appropriate in patients on chronic opioid therapy.
Overdose
If overdose is suspected, seek emergency medical attention immediately or contact your regional Poison Control Centre without delay.
- Excessive catharsis with significant fluid and electrolyte loss, abdominal cramping, and diarrhea.
Common side effects
- Abdominal cramping and diarrhea, particularly at higher doses.
Serious side effects
Serious side effects require immediate discussion with the prescriber or emergency care.
- Melanosis coli (brown pigmentation of the colonic mucosa) with chronic use — benign and reversible after discontinuation.
- Electrolyte disturbances (particularly hypokalemia) with chronic excessive use.
- Rare reports of a "cathartic colon" pattern (colonic dysmotility) with very prolonged, excessive stimulant laxative overuse; the clinical significance of this at recommended doses is debated.
Use with caution
- Use with caution in patients using it chronically without medical supervision for undiagnosed or worsening bowel symptoms.
- Use with caution in inflammatory bowel disease.
Contraindications
- Do not use in fecal impaction, intestinal obstruction, or acute abdominal conditions such as suspected appendicitis.
- Avoid in severe dehydration.
Drug interactions
- Chronic or excessive use may increase potassium loss, potentiating digoxin toxicity in patients also taking digoxin, and adding to the hypokalemic effect of diuretics or corticosteroids.
Food interactions
- No significant food interactions.
Time of administration
- Typically taken at bedtime, given the 6 to 12 hour onset of action, to produce a bowel movement the following morning.
Storage
- Store at room temperature, away from moisture.
- Keep out of reach of children.
Patient take-away
- Sennosides are a stimulant laxative that usually produces a bowel movement within 6 to 12 hours, so many people take it at bedtime.
- Short-term or as-needed use is typical, though your healthcare provider may direct ongoing use if you are on a long-term opioid pain medication.
- Contact your healthcare provider if you need to use it regularly for more than about a week without improvement, or if you develop severe cramping or diarrhea.