SENNA (SENNOSIDES)
(sen'na)
Black-Draught, Gentlax B, Sen-exon, Senokot, Senolax
Classifications: gastrointestinal agent; stimulant laxative
Prototype: Bisacodyl
Pregnancy Category: C

Availability

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

Actions

Prepared from dried leaflet of Cassia acutifolia or Cassia angustifolia. Similar to cascara sagrada but with more potent action. 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 Effects

Peristalsis stimulated by conversion of drug to active chemical.

Uses

Acute constipation and preoperative and preradiographic bowel evacuation.

Contraindications

Hypersensitivity; appendicitis, fecal impaction, irritable colon, nausea, vomiting, undiagnosed abdominal pain, intestinal obstruction; pregnancy (category C), lactation.

Cautious Use

Diabetes mellitus; fluid and electrolyte imbalances.

Route & Dosage

Constipation
Adult: PO Standard Senna Concentrate 1–2 tablets or ½–1 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 ½ 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.

Administration

Oral

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).

Pharmacokinetics

Onset: 6–10 h; may take up to 24 h. Metabolism: Metabolized in liver. Elimination: Excreted 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.
Do not breast feed while taking this drug.

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