ADSORBENTS & LAXATIVE By Wiwik Kusumawati

OBJECTIVE At the end of this topic the students will be able to : At the end of this topic the students will be able to : 1. Explain mechanism of action of both adsorbents and laxative agents 2. Explain side effects of both adsorbents and laxative agents 3. Explain indication of both adsorbents and laxative agents 4. Explain interactions between adsorbents and other drugs 5. Mention classification of laxative agents

Antidiarrheals 1. Adsorbents 2. Anticholinergics 3. Opiates

Adsorbents Mechanism of action Mechanism of action Coat the walls of the GI tract Coat the walls of the GI tract Bind to the causative bacteria or toxin, which is then eliminated through the stool Bind to the causative bacteria or toxin, which is then eliminated through the stool Examples: bismuth subsalicylate (Pepto- Bismol), kaolin-pectin, activated charcoal, attapulgite (Kaopectate) Examples: bismuth subsalicylate (Pepto- Bismol), kaolin-pectin, activated charcoal, attapulgite (Kaopectate)

Adsorbents Side Effects Side Effects Increased bleeding time Increased bleeding time Constipation, dark stools Constipation, dark stools Confusion, twitching Confusion, twitching Hearing loss, tinnitus, metallic taste, blue gums Hearing loss, tinnitus, metallic taste, blue gums

Adsorbents Interaction Interaction Adsorbents decrease the absorption of many agents, including digoxin, clindamycin, quinidine, and hypoglycemic agents Adsorbents decrease the absorption of many agents, including digoxin, clindamycin, quinidine, and hypoglycemic agents Adsorbents cause increased bleeding time when given with anticoagulants Adsorbents cause increased bleeding time when given with anticoagulants

CONSTIPATION Abnormally infrequent and difficult passage of feces through the lower GI tract Abnormally infrequent and difficult passage of feces through the lower GI tract Symptom, not a disease Symptom, not a disease Disorder of movement through the colon and/or rectum Disorder of movement through the colon and/or rectum Can be caused by a variety of diseases or drugs Can be caused by a variety of diseases or drugs

LAXATIVE AGENT Drugs used for treatment of acute constipation (drugs accelerating the passage of food through the intestine). Drugs used for treatment of acute constipation (drugs accelerating the passage of food through the intestine). A symptomatic therapy which should not be used chronically A symptomatic therapy which should not be used chronically

LAXATIVE AGENT 1. Bulk forming 2. Emollient 3. Hyperosmotic 4. Saline 5. Stimulant

Bulk forming High fiber High fiber Absorbs water to increase bulk Absorbs water to increase bulk Distends bowel to initiate reflex bowel activity Distends bowel to initiate reflex bowel activity Examples: Examples: –psyllium (Metamucil) –methylcellulose (Citrucel) –polycarbophil

Emollient Stool softeners and lubricants Stool softeners and lubricants Promote more water and fat in the stools Promote more water and fat in the stools Lubricate the fecal material and intestinal walls Lubricate the fecal material and intestinal walls Examples: Examples: –Stool softeners: docusate salts (Colace, Surfak) –Lubricants: mineral oil

Hyperosmotic Increase fecal water content Increase fecal water content Result: bowel distention, increased peristalsis, and evacuation Result: bowel distention, increased peristalsis, and evacuation Examples: Examples: –polyethylene glycol (GoLYTELY) –sorbitol –glycerin –lactulose (Chronulac)

Saline Increase osmotic pressure within the intestinal tract, causing more water to enter the intestines Increase osmotic pressure within the intestinal tract, causing more water to enter the intestines Result: bowel distention, increased peristalsis, and evacuation Result: bowel distention, increased peristalsis, and evacuation

Stimulant Increases peristalsis via intestinal nerve stimulation Increases peristalsis via intestinal nerve stimulation Examples: Examples: –castor oil –senna –cascara –bisacodyl

INDICATIONS Laxative Group Bulk forming EmollientUse Acute and chronic constipation Irritable bowel syndrome Diverticulosis Acute and chronic constipation Softening of fecal impaction; facilitation of BMs in anorectal conditions

INDICATIONS Laxative Group HyperosmoticSalineUse Chronic constipation Diagnostic and surgical preps Constipation Removal of helminths and parasites

INDICATIONS Laxative Group StimulantUse Acute constipation Diagnostic and surgical bowel preps

SIDE EFFECTS Bulk forming Bulk forming –Impaction –Fluid overload Emollient Emollient –Skin rashes –Decreased absorption of vitamins Hyperosmotic Hyperosmotic –Abdominal bloating –Rectal irritation

SIDE EFFECTS Saline Saline –Magnesium toxicity (with renal insufficiency) –Cramping –Diarrhea –Increased thirst Stimulant Stimulant –Nutrient malabsorption –Skin rashes –Gastric irritation –Rectal irritation