LACTOLOGY FOUNDATION

ATC class A06AB07 comprises stimulant “contact” laxatives based on cascara (Rhamnus purshiana / Rhamnus cathartica) bark, used short‑term for constipation and generally considered unsuitable during breastfeeding because of potential diarrheal effects in the infant.medpedia.framar+4

ATC Class A06AB07 Overview

ATC A06AB07 includes preparations containing cascara bark, a herbal stimulant laxative used in the management of constipation.brettelliott+2
Cascara belongs to the subgroup of contact laxatives (A06AB), which act primarily by stimulating colonic motility and altering water and electrolyte secretion in the large intestine.murciasalud+2

Active Constituents and Mechanism

Cascara bark contains anthraquinone derivatives, mainly anthraquinone glycosides and cascarosides (A–D), responsible for the laxative effect.sciencedirect+1
After oral administration, colonic bacteria hydrolyze these glycosides into active anthra‑derivatives that stimulate colonic peristalsis and reduce water reabsorption, resulting in softened stools and accelerated transit.brettelliott+1

Indications and Clinical Use

Medicines in class A06AB07 are indicated for short‑term treatment of occasional or chronic constipation, particularly when dietary and lifestyle measures are insufficient.breastfeedingnetwork+2
They are generally reserved for situations where bulk‑forming or osmotic laxatives are ineffective or inappropriate, given their higher risk of electrolyte disturbance and dependency with prolonged use.sps+2

Contraindications and Precautions

Cascara‑containing laxatives are contraindicated in patients with intestinal obstruction, acute abdominal conditions, markedly dilated or atonic colonic walls, and known hypersensitivity to cascara or related Rhamnus species.medpedia.framar+2
Use is not recommended in children, during pregnancy, or for long durations because of risks including severe diarrhea, dehydration, electrolyte imbalance, colonic atony, and reported liver toxicity with sustained high‑dose use.urmc.rochester+2

Adverse Effects

Common adverse reactions include abdominal pain, cramping, diarrhea, and associated loss of fluids and electrolytes.sciencedirect+2
With prolonged or excessive use, cascara may cause hypokalemia, dependency (need for laxatives to maintain defecation), and structural changes such as dilation or atony of the colon; benign darkening of urine has also been described with anthranoid laxatives.urmc.rochester+2

Dosage and Administration

Cascara bark is typically dried and administered orally in the form of tablets, capsules, or liquid preparations standardized to anthraquinone content, with dosing titrated to achieve a single, soft bowel movement daily.medpedia.framar+2
Because of its bitter taste, preparations may be combined with sweetening agents such as sugar or honey, but treatment courses should be limited to a few days and not repeated frequently without medical supervision.brettelliott+2

Drug Interactions

As stimulant cathartics, cascara products may enhance loss of potassium and other electrolytes, potentially increasing toxicity of concomitant cardiac glycosides and interacting with diuretics or corticosteroids that also lower potassium.murciasalud+2
Co‑administration with other laxatives or gastrointestinal agents can potentiate diarrhea and dehydration; careful monitoring of fluid status and electrolytes is advised when cascara is used together with such medicines.murciasalud+2

Lactation Safety Profile

Transfer into Breast Milk

Anthraquinone derivatives from cascara are partly absorbed and can be excreted into breast milk, though typically at low concentrations.e-lactation+1
Older, poorly documented reports suggest that these compounds may cause diarrhea in breastfed infants, leading several expert sources to advise against routine use of cascara while breastfeeding.ncbi.nlm.nih+3

Documented and Potential Infant Effects

LactMed and other lactation references note that maternal intake of cascara or buckthorn‑type cathartics may lead to loose stools in the nursing infant, and therefore recommend avoidance.ncbi.nlm.nih+2
In the absence of robust controlled studies, the main theoretical risks to the infant are diarrhea, dehydration, and electrolyte imbalance; any onset of unusually loose stools, irritability, or poor feeding should prompt immediate medical review.franciscanhealth+2

Comparative Lactation Recommendations

Multiple guidance documents on constipation in breastfeeding favor bulk‑forming or osmotic laxatives (e.g. ispaghula husk, sterculia gum, methylcellulose, lactulose, macrogols, magnesium salts) as first‑line options, owing to minimal systemic absorption and better safety data.mayoclinic+3
Stimulant laxatives are considered second‑line and, when needed, short courses of senna or bisacodyl at moderate doses are generally preferred over cascara, given more established experience and clearer lactation recommendations.sps+2

Divergent Classifications

Some classification systems have historically placed cascara in a relatively favorable lactation risk category (e.g. category A or “quite safe” in certain regional sources), reflecting limited evidence of serious adverse effects.e-lactancia+1
However, modern expert resources such as LactMed, e‑lactancia and clinical monographs increasingly advise prudence or avoidance during breastfeeding because of the potential for infant diarrhea and the availability of safer alternatives.e-lactancia+3

Clinical Positioning in Breastfeeding

For breastfeeding women, cascara‑containing preparations (A06AB07) are generally not recommended as first‑line therapy; safer options include non‑pharmacological measures and non‑absorbed or minimally absorbed laxatives.breastfeedingnetwork+3
If, in exceptional circumstances, cascara is considered, it should be used at the lowest effective dose for the shortest possible time, with close monitoring of the infant for changes in stool frequency or consistency and prompt discontinuation if adverse effects appear.ncbi.nlm.nih+3