PurgativesLaxatives

1. Purgatives=Laxatives

2. Objectives: By the end of this lecture the student should be able to know: - Definition and causes of constipation -Management of constipation - Different classes of purgatives, at least one or tow examples on each and their MOA - Major side effects to purgatives

3. Constipation Constipation is one of the most common digestive complaints It varies greatly between different people, as each persons bowel movements differ Most cases of constipation are caused by a low fiber diet and/or dehydration

4. The stool can be hard and dry. Constipation is most common in children and older people, and affects women more than men.  One in 200 women have severe, continuous constipation and it is most common before a period and during pregnancy.

5. Causes of constipation: ** In adults Often there is no identified cause of constipation, but it may be due to one or a number of the following factors: - Not enough fluid (water) in the diet - Not enough fiber (fruit, vegetables, cereals) in the diet. 

6. - Drugs such as analgesics ( Morphine, Codeine ), antidepressants, and antacids ( aluminum and Calcium salts ) - Too much calcium in the diet - Too much iron in the diet - Pregnancy

7. - Drinking an excessive amount of strong tea or coffee (this increases urine production and so decreases the amount of fluid in the bowel) - Recent abdominal surgery, hemorrhoids, or anal fissure can make it painful to defecate and lead to constipation - Anxiety in some people can lead to constipation

8. ** In babies and children - Not enough fiber in a child's diet - Not getting enough fluids - Any illness with high fever and vomiting, can cause dehydration and lead to constipation. - An allergy to cows milk or medicines may also cause constipation

9. - Very rarely, in babies, constipation may be a sign of a disorder, such as hypothyroidism, or anal stenosis - Constipation is also more common in children with Down's syndrome, cerebral palsy and spina bifida.

10. ** Travelling, constipation is often experienced by people when they are travelling or on holiday ( diarrhea is more common ) This is because of the change in their normal routine diet

11. ** The following conditions may lead to constipation: - Irritable bowel syndrome (IBS) - Kidney failure - Colon/rectal cancer - Multiple Sclerosis (MS) - Spinal injury - Hypothyroidism

12. Management of constipation: - Treatment of the cause - Preventive measures: - Eating more fruits, vegetables and grains, which are high in fiber - Drinking plenty of water and other liquids

13. - Getting enough exercise - Asking your doctor if medicines you take may cause constipation - Using laxatives only if your doctor says you should

14. Purgatives=Laxatives Definition An over-the-counter (OTC) drugs that promote passage of feces mainly by reducing the viscosity of the contents of lower colon or simply drugs that relieve constipation, including bulk-forming laxatives, lubricants, stool softeners, saline laxatives, stimulant laxatives and combinations

15. Classes and MOA of purgatives 1.- Bulk-forming laxatives High fiber diet ( green vegetables, fruits) Methylcellulose Polycarbophil Ispaghula husk psllium They are not absorbed and add bulk and water to stools. The larger stools help trigger the bowel to contract and move the stools out

16. 2.- Lubricant laxatives Glycerin Mineral oil They loose stools and lubricate the intestine They work by coating the surface of the stools This helps the stools hold in water so they move out of the body more easily

17. 3.- Stool softeners Docusate sodium Help mix fluid and water into stools to soften them This makes stools easier to pass out of the body

18. 4.- Saline laxatives Magnesium hydroxide (milk of Magnesia) Magnesium sulfate (Epsom salt) Draw fluids and water into the bowel from nearby tissue by osmosis This softens stools and helps the bowel move them out

19. 5.- Stimulant laxatives Bisacodyl Castor oil Senna, Rhubarb… and many others Stimulant or irretant purgatives are the harshest laxatives. They cause the bowel to squeeze or contract to move the stools out.

20. Stimulant laxatives should generally be used only when they are recommended by the physician, such as in cases of preparing for a bowel exam or after surgery when patients shouldn’t strain to have a bowel movement ( e.g. patients with HF or hemorrhoids)

21. Purgatives are available in tablets, syrup, powder and suppositories dosage forms Common side effects of laxatives: Most laxatives don’t have side effects Sometimes they can cause diarrhea ( major side effect) cramping, gas, bloating, nausea and allergy

22. Stimulant laxatives are most likely to cause side effects Mineral oil if accidentally aspirated it can cause a type of pneumonia Chronic use of purgatives is not advised