Question 1

How does cascara sagrada work as a laxative?

Accepted Answer

Cascara sagrada (Frangula purshiana) contains anthraquinone glycosides called cascarosides A-D, which are metabolized by intestinal bacteria into active compounds. These metabolites stimulate colonic smooth muscle contraction and increase fluid secretion into the intestinal lumen, promoting bowel movement. The laxative effect typically occurs 6-12 hours after ingestion. This mechanism makes it a stimulant laxative, distinct from bulk-forming or osmotic laxatives. Evidence Level: C.

Question 2

Does cascara sagrada interact with any medications?

Accepted Answer

Cascara sagrada can interact with several medication classes. Due to potential potassium depletion from chronic use, it may increase toxicity risk from cardiac glycosides like digoxin. It may potentiate potassium-wasting effects of diuretics and corticosteroids, worsening electrolyte imbalances. Concurrent use with other stimulant laxatives increases adverse effect risk. Patients on heart medications, diuretics, or corticosteroids should consult a healthcare provider before use. Evidence Level: C.

Question 3

What is the recommended dosage for cascara sagrada bark?

Accepted Answer

The standard adult dosage is 300-500mg of aged bark extract or 1-2 grams of dried aged bark prepared as a tea, taken once daily at bedtime. The bark must be aged at least one year before use, as fresh bark contains emetic compounds that cause severe gastrointestinal irritation. Effects typically occur within 6-12 hours. Use should be limited to short-term duration of 1-2 weeks maximum. Evidence Level: C/Traditional.

Question 4

Is cascara sagrada safe during pregnancy and breastfeeding?

Accepted Answer

No, cascara sagrada is contraindicated during pregnancy and breastfeeding. The anthraquinone compounds can stimulate uterine contractions, potentially causing miscarriage or premature labor. Active metabolites may pass into breast milk, causing diarrhea and electrolyte disturbances in nursing infants. Pregnant and breastfeeding individuals should avoid all stimulant laxatives containing anthraquinones. Safer alternatives include dietary fiber, adequate hydration, and osmotic laxatives under healthcare provider guidance. Evidence Level: C/D.

Question 5

What are the side effects of long-term cascara sagrada use?

Accepted Answer

Long-term cascara sagrada use can cause electrolyte imbalances, particularly hypokalemia, which may affect heart rhythm and muscle function. Melanosis coli, a benign dark pigmentation of the colon lining, may develop after extended use and typically resolves after discontinuation. Chronic use can lead to laxative dependency and cathartic colon, where the colon becomes unresponsive to normal stimuli. Use should not exceed 1-2 weeks without medical supervision. Evidence Level: C.

Frangula Purshiana

Sources & Citations

Summary

Background

Traditional uses

Active compounds

Mechanism of action

Clinical evidence

Safety & adverse effects

Pregnancy & lactation

Evidence summary

PubMed sources

Government sources