VPT 311: General and Systemic Veterinary Pharmacology (2+1)

PURGATIVES AND LAXATIVES

• Purgatives are drugs which cause marked intensification of intestinal activity and results in the expulsion of intestinal content from the colon and rectum.
• The terms aperient and cathartic are also applied to describe the purgatives. A distinction is made according to the intensity of action.
• Laxative or aperient: are milder in action, elimination of soft but formed stools
• Purgatives or cathartic: are stronger action resulting in more fluid evacuation.
• Laxative and cathartics are used for:
  • Relief of acute non dietary constipation
  • Removal poisons from the gastrointestinal tract
  • Prevention of tenesmus in advanced pregnancy or prolapse
  • Evacuation of the bowel prior to surgery or radiography
• Many drugs in low doses act as laxative and in larger doses as purgatives.
• Type of stools and latency of action of purgatives employed in usually recommended doses

Soft formed feces (take 1-3 days)	Semi fluid stools (take 6-8 hours)	Watery evacuation (within 1-3 hours)
Bulk forming Docusates Liquid paraffin Lactulose	Phenolphthalein Bisacodyl Senna	Saline purgatives Castor oil