Black-Draught, Gentlax B, Senexon, Senokot, Senolax
Classifications: stimulant laxative;
Therapeutic: stimulant laxative

Prototype: Bisacodyl
Pregnancy Category: C


8.6 mg, 15 mg, 25 mg tablets; 8.6 mg/5 mL, 15 mg/5 mL syrup


Prepared from dried leaflet of Cassia acutifolia or Cassia angustifolia. Senna glycosides are converted in colon to active aglycone, which stimulates peristalsis. Concentrate is purified and standardized for uniform action and is claimed to produce less colic than crude form.

Therapeutic Effect

Peristalsis stimulated by conversion of drug to active chemical.


Acute constipation and preoperative and preradiographic bowel evacuation.


Hypersensitivity; appendicitis, fecal impaction; fluid and electrolyte imbalances; irritable colon, nausea, vomiting, undiagnosed abdominal pain, intestinal obstruction; children <6 y; pregnancy (category C), lactation.

Cautious Use

Diabetes mellitus; children >6 y; fluid and electrolyte imbalances.

Route & Dosage

Adult: PO Standard Senna Concentrate 1–2 tablets or ?–1 tsp h.s. (max: 4 tablets or 2 tsp b.i.d.); Syrup, Liquid 10–15 mL at h.s.
Child: PO Standard Senna Concentrate >27 kg, 1 tablet or ? tsp h.s.; Syrup, Liquid 1 mo–1 y, 1.25–2.5 mL h.s.; 1–5 y, 2.5–5 mL h.s.; 5–15 y, 5–10 mL h.s.


  • Give at bedtime, generally.
  • Avoid exposing drug to excessive heat; protect fluid extracts from light.

Adverse Effects (≥1%)

GI: Abdominal cramps, flatulence, nausea, watery diarrhea, excessive loss of water and electrolytes, weight loss, melanotic segmentation of colonic mucosa (reversible).


Onset: 6–10 h; may take up to 24 h. Metabolism: In liver. Elimination: In feces.

Nursing Implications

Assessment & Drug Effects

  • Reduce dose in patients who experience considerable abdominal cramping.

Patient & Family Education

  • Be aware that drug may alter urine and feces color; yellowish brown (acid), reddish brown (alkaline).
  • Continued use may lead to dependence. Consult physician if constipation persists.
  • See bisacodyl for additional nursing implications.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

© 2006-2023 Last Updated On: 01/29/2023 (0)
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