calcium sennosides: clinical use

Prescribing considerations

• Exclude obstruction, faecal impaction and acute unexplained abdominal symptoms before use.
• Investigate persistent constipation or repeated laxative need.
• Consider dehydration, renal impairment, older age and medicines affecting potassium balance.

Contraindications and cautions

• Hypersensitivity to calcium sennosides or an excipient
• Intestinal obstruction or stenosis, bowel atony, appendicitis or faecal impaction
• Crohn's disease, ulcerative colitis or unexplained abdominal pain
• Severe dehydration with water and electrolyte depletion
• Concurrent use of another laxative
• Children under 12 years for the selected syrup
• Pregnancy and lactation for the selected syrup
• Hereditary fructose intolerance because the syrup contains maltitol

Monitoring

• Assess hydration and electrolytes, particularly potassium, in severe diarrhoea, suspected excessive use, renal impairment or older people.
• Review for hypokalaemia when interacting medicines or liquorice are involved.
• Persistent or worsening symptoms, or absent bowel action despite use, require clinical review.

Clinical pharmacology

Sennosides are poorly absorbed glycosides activated by colonic bacteria. Rhein anthrone accelerates colonic transit and increases luminal water and electrolytes through antiabsorptive and secretory actions.

Formulation and product differences

• The selected product is a prune-flavoured oral syrup containing maltitol, methyl and propyl parahydroxybenzoates, potassium and a small amount of ethanol.
• Maltitol may have a mild laxative effect and makes the syrup unsuitable in hereditary fructose intolerance; parabens can cause allergic reactions, sometimes delayed.
• Product-specific age, pregnancy, breastfeeding and concurrent-laxative restrictions may differ from general advice about other senna preparations.

Syrup

Route: Oral

Strengths: 7.5 mg/5 mL