Generic Name

Senokot

Mechanism

Senokot contains sennosides A and B, anthraquinone glycosides that are biologically inactive until converted by colonic bacteria into active lactones (rhein and emodin).
• Stimulation of colonic mucosa: The active lactones depolarize the enteric nerve endings, triggering smooth‑muscle contraction.
• Increased colonic fluid secretion: They inhibit sodium‑potassium exchange, enhancing water and electrolyte entry into the lumen.
• Rapid onset (30–90 min) and short duration (≈ 1 day), making it effective for acute constipation or intermittent use.

Pharmacokinetics

Indications

• Acute constipation (e.g., post‑operative, after long travel).
• Chronic constipation (≤ 4 weeks) for symptom relief.
• Intermittent constipation or scheduled bowel preparation.
• Pediatric constipation (≥ 6 yrs) with physician guidance.

Contraindications

• Intestinal obstruction or perforation.
• Inflammatory bowel disease (active ulcerative colitis, Crohn’s disease).
• Severe electrolyte imbalance (hypokalemia, hyponatremia).
• Pregnancy: Category C—use only if benefits outweigh risks; short courses  4 weeks of continuous therapy.
• Pseudomembranous colitis: Contraindicated due to potential exacerbation.
• Allergy to senna or other anthraquinone laxatives.

Dosing

• Adults & Adolescents (≥ 12 yrs): 15 mg (1 tablet) 1–2 times per day, maximum 30 mg/day.
• Children (6–11 yrs): 5 mg (½ tablet) once daily; titrate based on response.
• Geriatric: Start at lower end (≤ 15 mg) to reduce cramping.
• Extended‑Use: Not recommended beyond 4 weeks without medical supervision.
• Administration: Oral, with a full glass of water; can be taken with or without food.
• Missed dose: Take as soon as remembered; skip if later in the day.

Adverse Effects

Monitoring

• Vital signs: BP, pulse (especially if diarrhea or dehydration suspected).
• Electrolytes: Serum potassium, sodium, chloride every 2–4 weeks in chronic users.
• Renal function: eGFR baseline, particularly in elderly or chronic kidney disease.
• Hydration status: Oral intake, urine output, weight.
• Bowel habits: Document frequency, consistency, and any abdominal discomfort.

Clinical Pearls

• Short‑Term Safeguard: Use Senokot only for ≤ 4 weeks to avoid laxative dependence and colonic mucosal adaptation.
• Pregnancy & Lactation: A lower dose (5–10 mg) is still considered the safest option; always consult obstetrics/radiology for contrast studies.
• Drug‑Drug Synergy: Co‑administer with magnesium hydroxide or aluminium hydroxide *only* if a 1‑h buffer is observed; these antacids can reduce efficacy.
• Tolerance & Break‑In: Take break days 4‑7 of a 2‑week cycle to maintain colonic sensitivity.
• Patient Education: Instruct patients to increase fluid intake (≥ 2 L/day) and incorporate fiber to mitigate cramping and promote stool bulk.
• Differential Tolerance: Elderly or comorbid patients occasionally experience *prolonged* diarrhea (> 30 min); promptly report any extended loose stools.
• Monitoring for Rebound: When discontinuing Senokot, gradually taper by reducing dose by 5 mg every 3–5 days to prevent rebound constipation.

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• Key Terms: *senna*, *anthraquinone*, *lactones*, *intestinal motility*, *electrolyte imbalance*, *short‑term use*.