Mode of action
Act by direct stimulation of nerve endings in colonic mucosa to increase intestinal motility. May cause accumulation of water and electrolytes in the colonic lumen.
Indications
Constipation.
Contraindications
Intestinal obstruction, partial or complete, Acute abdominal conditions, e.g. appendicitis, Inflammatory bowel condition.
Specific considerations
Elderly: Increased risk of faecal incontinence.
Pregnancy: Avoid direct stimulants except for occasional doses; ADEC category A.
Lactation: May be used.
Adverse effects
Infrequent: discolouration of urine (yellowish brown or red)
Rare: nephritis (with large doses), hepatitis, melanosis coli (chronic use)
Dosage
Adult: 7.5–30 mg at bedtime.
Child
6–12 years, 7.5–15 mg at bedtime.
2–6 years, 3.75–7.5 mg at bedtime.
Practice points
onset of action is 6–12 hours
Products
SENNA TABS (LAXAL®, SENNOKET®, SENNA LAX®)