LACTOLOGY FOUNDATION

Senna glycosides (ATC A06AB06) are stimulant “contact” laxatives used orally or rectally for short‑term relief of constipation and bowel preparation, and they can generally be used during breastfeeding with caution and infant monitoring.medpedia.framar+4

Identification and pharmacological class

·        INN / group name: Senna glycosides (sennosides; senna).

·        ATC code: A06AB06, subgroup “contact laxatives” within A06 “drugs for constipation”.atcddd.fhi+2

·        Chemical nature: Mixture of anthraquinone‑derived dianthrone glycosides (primarily sennosides A and B) obtained from Cassia senna species.wikipedia+1

·        Pharmacological class: Stimulant (contact) laxatives acting mainly on the large intestine to promote defecation.wikidoc+2

Mechanism of action and pharmacokinetics

Senna glycosides act as prodrugs: they are poorly absorbed in the upper gastrointestinal tract and reach the colon largely unchanged. In the large intestine, bacterial enzymes hydrolyse the glycosides to active anthraquinone metabolites (including rhein anthrone) that stimulate mucosal fluid secretion and colonic peristalsis. Clinically, this leads to increased water content and bulk of faeces, which facilitates bowel evacuation.drugbank+3

After oral administration, onset of action typically occurs within 6–12 hours, reflecting the time needed for colonic transformation and stimulation. Rectal administration produces more rapid effects, usually within about 30 minutes. Systemic bioavailability of unchanged sennosides is minimal, but small quantities of rhein (an active metabolite) can be detected in plasma and are excreted in urine and breast milk in very low concentrations. Elimination of metabolites is predominantly renal and biliary, with negligible accumulation when used short‑term at recommended doses.webmd+3

Indications and clinical use

Senna glycosides are indicated for:

·        Short‑term treatment of constipation in adults and children above the minimum age specified by national product information.medpedia.framar+2

·        Facilitation of bowel evacuation before surgery or diagnostic procedures such as colonoscopy or other rectal/colonic examinations, usually as part of combined bowel‑prep regimens.wikipedia+2

They are generally recommended for occasional or short‑course use; chronic or long‑term administration should only occur under medical supervision because of the risk of electrolyte disturbances and laxative dependency.breastfeedingnetwork+2

Posology

Dosing varies between proprietary products and national recommendations; typical patterns are:

·        Adults and adolescents: Oral administration once daily, usually at night, with doses titrated to the lowest effective amount (for example 1–2 tablets or equivalent extract).bnf.nice+2

·        Children: Use is commonly restricted to those above 6–12 years of age, with reduced doses (for example 1 tablet) and only on medical advice.webmd+2

·        Route of administration: Oral (tablets, capsules, granules, liquid preparations) or rectal (suppositories) depending on formulation.medpedia.framar+2

In all cases, treatment duration should be as short as possible, typically not exceeding one week without professional review.breastfeedingnetwork+2

Contraindications and precautions

Absolute and relative contraindications include:

·        Acute or chronic inflammatory bowel diseases such as ulcerative colitis and Crohn’s disease.wikidoc+2

·        Acute surgical abdominal conditions (e.g. suspected appendicitis, intestinal obstruction/ileus, acute abdomen) and undiagnosed severe abdominal pain.wikipedia+2

·        Severe dehydration or marked fluid and electrolyte depletion, particularly hypokalaemia.bnf.nice+2

·        Children below the age specified in local product information (often under 6–7 years).webmd+1

Precautions:

·        Use with caution in patients at risk of electrolyte imbalance (e.g. elderly, patients on diuretics, corticosteroids, or other potassium‑lowering drugs).bnf.nice+2

·        Avoid prolonged continuous use to prevent secondary atony of the colon and potential melanosis coli; intermittent or occasional dosing is preferred.breastfeedingnetwork+1

·        Inform patients that normalisation of diet, fluid intake and physical activity should accompany pharmacological treatment whenever possible.breastfeedingnetwork

Adverse effects and toxicity profile

Common adverse reactions include:

·        Abdominal cramping or colicky pain, bloating and flatulence.medpedia.framar+2

·        Diarrhoea or loose stools, particularly with higher doses.webmd+2

Less frequent or prolonged use‑related effects:

·        Excessive diarrhoea with resultant fluid and electrolyte loss, especially hypokalaemia, which may precipitate or worsen cardiac arrhythmias in susceptible individuals.bnf.nice+2

·        Reactive changes in colonic mucosa such as reversible melanosis coli with long‑term anthraquinone laxative exposure.wikipedia

Allergic reactions (e.g. cutaneous hypersensitivity) are uncommon but possible. Overall, when used briefly at recommended doses, senna glycosides have a favourable safety profile in the general population, though stimulant laxatives are usually second‑line compared with bulk or osmotic laxatives, particularly in vulnerable groups.sps+3

Drug interactions

Senna glycosides can influence the absorption and effect of concomitant medication through accelerated intestinal transit. Clinically relevant interactions include:medpedia.framar+1

·        Enhanced risk of hypokalaemia when combined with thiazide or loop diuretics, systemic or high‑dose corticosteroids, and certain antiarrhythmic agents.webmd+2

·        Potential increase in digoxin toxicity due to laxative‑induced potassium depletion.wikipedia+1

Because of these effects, careful monitoring and possible dose adjustments of interacting drugs are advisable when senna glycosides are used beyond very short courses.bnf.nice+2

Use during pregnancy

Available animal data on sennosides A and B have not demonstrated teratogenicity, and limited human experience has not revealed a clear association with major malformations. Nevertheless, robust controlled clinical data in pregnancy are lacking, and most guidelines recommend that stimulant laxatives, including senna, be reserved for situations where benefit clearly outweighs potential risk, preferably after dietary and non‑stimulant options have failed. When required, short‑term use at the lowest effective dose is preferred, under medical supervision.drugs+3

Lactation (toxico‑lactological assessment)

Transfer into breast milk

Senna itself is not measurably excreted in human milk, but its active metabolite rhein appears in breast milk in very small amounts after maternal intake of senna preparations. These concentrations are generally far below therapeutic levels and are unlikely to produce significant systemic exposure in the breastfed infant.drugs+1

Reported effects in breastfed infants

Clinical experience and small observational studies have not demonstrated consistent serious adverse effects in breastfed infants whose mothers used senna; most guidelines therefore consider senna compatible with breastfeeding when used appropriately. Some case reports and reviews mention episodes of loose stools or mild diarrhoea in infants, even when senna levels in breast milk were undetectable, suggesting possible sensitivity in some infants or indirect effects on stool patterns. No long‑term toxicity, growth impairment, or serious gastrointestinal pathology has been convincingly linked to maternal senna use in lactation.thewomens+5

Comparative lactation safety and recommendations

Professional organisations and specialist services generally classify senna as:

·        Acceptable or “compatible with breastfeeding” when used short‑term and at standard doses, with observation for changes in infant stool consistency.infantrisk+3

·        Less preferred than non‑stimulant options (bulk or osmotic laxatives such as lactulose, macrogol, glycerol or stool softeners like docusate), which are regarded as first‑line during breastfeeding because of minimal systemic absorption and negligible milk transfer.thewomens+2

Therefore, in a toxicological‑lactological context:

·        Maternal risk: At recommended doses, systemic toxicity is low; main risks are diarrhoea and electrolyte loss with overuse.medpedia.framar+2

·        Infant risk via milk: Very low, but occasional loose stools are possible; routine monitoring of hydration and stool frequency/consistency is prudent.sps+2

Long‑term, high‑dose or unsupervised use in breastfeeding women is discouraged because it increases the likelihood of maternal adverse effects without clear additional clinical benefit and may theoretically accentuate infant stool changes.breastfeedingnetwork+1

Clinical positioning in breastfeeding women

For constipation in breastfeeding women:

·        Optimisation of diet, fluid intake and physical activity should be encouraged before pharmacological interventions.breastfeedingnetwork

·        Bulk and osmotic laxatives (e.g. lactulose, macrogol, glycerol) are preferred as first‑line because they are safe and have negligible milk transfer.thewomens+2

·        Senna glycosides can be used as second‑line or for short‑term rescue therapy when response to first‑line agents is inadequate, provided the mother is counselled about possible transient changes in infant stool pattern and the need to avoid prolonged self‑medication.sps+1

In summary, senna glycosides (A06AB06) are generally compatible with breastfeeding when used briefly and appropriately, but they should not replace safer first‑line laxatives for long‑term management.drugs+2

Example of related laxatives (context for clinicians)