jalap

Jalap refers to the dried tuber of Ipomoea purga, a climbing plant in the morning-glory family native to Mexico and Central America. The root has long been used as a laxative. The name is linked to Xalapa (Jalapa), a Mexican town through which the root was historically exported to Europe.

Pharmacology and preparation: The purgative activity comes from resinous glycosides present in the root, notably compounds traditionally referred to as jalapin and related constituents. When ingested, these substances irritate the intestinal mucosa and stimulate peristalsis, producing bowel evacuation with abdominal cramps. Onset of effect is usually several hours after oral dosing, commonly around 6 to 12 hours. Effects can be strong and may be accompanied by nausea, vomiting, and dehydration. Because of its potency and potential for electrolyte disturbances, dosing must be precise and medical supervision is advised.

History and use: Jalap entered European medicine in the 16th–17th centuries and remained a common stimulant laxative through the 18th and 19th centuries. It appeared in many pharmacopoeias and proprietary purgatives. In modern pharmacology and clinical practice, use of jalap has declined due to safety concerns and the availability of safer laxatives.

Safety and status: Jalap is rarely used in contemporary medicine. It is contraindicated in cases of intestinal obstruction, inflammatory bowel disease with risk of perforation, and dehydration. Potential adverse effects include severe cramps, diarrhea, vomiting, and electrolyte imbalance. Today, jalap is primarily of historical and pharmacognostic interest rather than a routine therapeutic agent.