Drugs used to treat Diarrhea & Costipation Assistant Professor Dr. Shamil AL-Neaimy

Drugs used to treat diarrhea: Treatment of the cause Correction of fluids and electrolytes imbalance . Treatment is by increasing viscosity (pectin ,kaolin ,chalk ) ,binding toxines ,delaying passage of contents (opiods) ,and decreasing the motility of intestine (by inhibiting Ach. Release ).

Drugs: 1-Diphenoxylate : related to pethidine mixed with atropine to form LOMOTIL. Precausions : liver disease, severe colitis ,and children. 2-Diphenoxin: active metabolite of diphenoxylate . 3-Loperamide: causing abdominal cramps.

Drugs used to treat constipation: (Laxative , Purgative , Cathartic) Constipation: Habitual , related to diet , psychological , drugs (opioids) , pregnancy ,or due to disease (eg DM). Treatment is by increasing bulk and viscosity of feces and increasing motor activity of the gut.

3 groups of drugs : 1-Stimulant (irritant):   1-Stimulant (irritant): Bisacodyl: synthetic drug , stimulates sensory endings in the colon , used in elderly people causing abdominal discomfort . Phenolphthalin: potent stimulant acts directly on colon causing skin allergy & red stool .

Senna : stimulates peristalsis . Sodium picosulfate : used in surgery . Oxyphenacitin : used in surgery . Glycerol: stimulates rectum.

2-Bulking agents : They increase volume & decrease viscosity , holding water in the gut & stimulate normal reflex. Two groups of drugs: I-Hydrophilic colloids . II-Osmotic laxatives .

Hydrophilic colloids: Prepared from indigestable parts of vegetables & seeds . a-Bran : residue left from cereals , that has fibres consisting of cellulose , hemicellulose & non-carbohydrate polymers .It has the ability to retain water . Side effects : flatulence , distension , & intestinal obstruction . b-Methyl-cellulose : c-Psyllium: d-Agar : e-Ispaghula :

Osmotic laxatives(saline cathartic): Non-absorbable salts hold water in intestine by osmosis causing distension : a-magnesium sulfate (Epson salt): b-magnesium hydroxide: c-magnesium citrate : d-sodium citrate : e-sodium sulfate :

3-Fecal softeners (emolients): a-Surface active agent (dioctyl): b-Liquid paraffin: inert oil, indigestible.

Drugs used to treat Irritable Bowel Disorders: (Crohn’s disease , Ulcerative colitis) 1-Sulphasalazine: It’s a combination of sulphapyridine and 5-aminosalicylic acid ,used to treat ulcerative colitis more than crohn’s disease. MOA: cytoprotective action ,or inhibition of breakdown of PGF2 alpha ,or by suppressing immune response. Side Effects: serum sickness ,bone marrow suppresion ,and oligospermia.

2-Prednisolone 3-Azathioprime 4-Mercaptopurine

Drugs used to treat Hemorrhoids: 1-Soothing agents: a-Astringents: Bismuth , Zinc oxide , and Benzylbenzoate . b-Local anesthetics: Lignocaine. 2-Corticosteroids: Betamethasone , hydrocortisone , and prednisolone. 3-Rectal sclerosants: Oily phenol injection 5%.

Drugs used to treat gall bladder disease: 1-Ursodiol 2-Chenodiol MOA: supress hepatic synthesis of cholesterol and cholic acids. Side Effects: change hepatic function and diarrhea.