Definition of Purgative:
Purgatives are the strongest acting, are often combined with emetics and will completely clear the system. They are not often used in modern medicine due to their toxicity, but were frequently used by the Eclectics. An example is Ipecacuanha [Brammer BOTM744].
Cathartics and Purgatives (Gr. cleansing; L. purgare, to cleanse). These increase or hasten intestinal evacuations:
[Culbreth1927, pp 43-44].
- Simple Purgatives - which cause active peristalsis and stimulate secretion of the intestinal glands, giving one or more copious, semi-fluid movements accompanied by some irritation and griping: aloe, calomel, castor oil, cascara sagrada, rhubarb, senna, small doses of salines, drastics, cholagogues;
- Saline Purgatives - which stimulate the intestinal glands, increase peristalsis and osmosis, causing watery stools: magnesium sulfate and citrate, potassium sulfate, tartrate and bitartrate, sodium sulfate, phosphate and chloride, potassium and sodium tartrate;
- Drastic Purgatives (Gr. to act, active). These often are called simply cathartics, and act more intensely than Aperients, Laxatives, and the above, causing violent peristalsis, watery stools, griping, tenesmus, borborygmus, mucous membrane irritation, and exosmosis of serum; large doses become irritant poisons: colocynth, jalap, gamboge, scammony, croton oil;
- Hydragogue Purgatives (Gr. water + to lead, leading forth) which remove much water from the vessels: croton oil, elaterium, gamboge, potassium bitartrate, large doses of salines and drastics;
- Cholagogue Purgatives (Gr. bile + to lead, leading forth) which stimulate bile flow, causing free purgation of green-colored (bilious) and liquid stools: mercurials, aloe, rhubarb, podophyllin, euonymin, iridin, leptandrin.
(like cathartic) drastic laxative action - not intended for the weak [Palmer2004].