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Antidiarrheal drugs. Diarrhea: Too rapid evacuation of too fluid stools Most patients with sudden onset of diarrhea have a benign self-limited illness requiring no treatment or evaluation.
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Diarrhea: Too rapid evacuation of too fluid stools Most patients with sudden onset of diarrhea have a benign self-limited illness requiring no treatment or evaluation. Oral rehydration solution is the cornerstone for patients with acute illnesses resulting in significant diarrhea
Acute diarrhea Rehydration. WHO ORS: 1.Sodium chloride: 3.5g 2.Sodium bicarbonate: 2.5g Or Trisodium citrate: 2.9g 3.Potassium chloride 1.5g 4.Glucose: 20g 5.Potable water: 1 liter Rice based physiological solutions. Rationale of ORS
Home solution: ½ tsp salt (3.5g) 1 tsp baking soda (2.5g NaHCO3) 8 tsp sugar (40g) 8 oz orange juice (1.5g KCl) 1 L water
Antidiarrheal drugs: treat only symptoms! – Diarrhea is usually caused by infection (Salmonella, shigella, campylobacter,clostridium, E. coli), toxins, anxiety, drugs… – In healthy adults mostly discomfort and inconvenience – In children (particularly mal-nourished) a principal cause of death is due to excessive loss of water and minerals.
Antimotility agents: • – Muscarinic receptor antagonists (not useful due to side effects) and opiates: • Diphenoxylate • Difenoxin • Loperamide • – All have CNS effects – to be use carefully in treatment of diarrhea!
Antimotility agents & anti-secretory agents: • Opiods continue to be used widely • Mechanism of action: • Intestinal motility-- receptors • Intestinal secretion-- receptors • Intestinal absorption--- & receptors • All the commonly used opioids act principally via peripheral receptors and are preferred over opioids that penetrate central nervous system
Loperamide: • 40-50 times more potent than morphine as an anti- diarrheal agent • Increases small intestinal and mouth to cecum transit time. • Increases anal sphincter tone • Anti-secretory activity against cholera toxin and some forms of E.coli toxin
Loperamide: Half- life 11 hours Dose: 4mg initially followed by 2mg after each subsequent stool, up to 16mg/day. If clinical improvement does does not occur in acute diarrhea within 48 hours, DISCONTINUE loperamide Not recommended in children <2 years.
Loperamide: • Effective in travellers diarrhea • Used alone or in combination with antimicrobial agents (trimethorim with or without sulfamethoxazole) • Adjunctive treatment in almost all forms of chronic diarrheal diseases. • Lacks significant abuse potential • Overdose: CNS depression, paralytic ileus, toxic megacolon.
Difenoxin- • Active metabolite of diphenoxylate • Both combined with 25 mcg of atropine to prevent abuse. • Excess dose: CNS effects, anticholinergic effects, constipation, toxic megacolon • Other opioids: • Paregoric: 2mg morphine/5mL. • Deodorized tincture of opium.
DO not use loperamide in: • Patients with bloody diarrhea • High fever • Systemic toxicity • Worsening diarrhea despite treatment
Racecadotril: • A dipeptide • Reinforces effects of endogenous enkephalins on the opioid receptor • Leads to anti-diarrheal effect
Bismuth subsalicylate: Trivalent bismuth suspended in a mixture of magnesium aluminium silicate clay. In stomach: Combines with HCl Bismuth oxychloride + Salicylic acid
Bismuth subsalicylate • 2 tab or 30mL up to 8 times daily • Anti-inflammatory • Anti-bacterial • Anti- secretoty • Also decreases vomiting
Diphenoxylate and atropine contraindicated in acute diarrhea because of rare precipitation of toxic megacolon. GIVE APPROPRIATE ANTIBIOTICS, IF CAUSATIVE ORGANISM IS KNOWN
Rifaximin: Non absorbed oral antibiotic . 200mgtid x 3 days Ciprofloxacin 500mg Ofloxacin 400mg X 5 to 7 days Norfloxacin 400mg bd Levofloxacin 500mg od Cortrimoxazole DS bd Doxycycline 100mg bd
Liquid paraffin - No longer recommended - more ADR Malabsorption of fat soluble vitamins It foreign body reactions in small bowel (paraffinoma fecal leak at anal canal & pruritus ani
Treatment of Chronic diarrhea A number of antidiarrheal agents may be used in certain patients with chronic diarrheal conditions. Opioids are safe in most patients with chronic, stable symptoms. Loperamide:4mg initially ,then 2 mg after each loose stool ( maximum: 16 mg/d). Diphenoxylate with atropine:One tablet three or four times daily as needed.
Treatment of Chronic diarrhea Codeine and tincture of opium: Chronic, intractable diarrhea. Codeine 15-60 mg every 4 hours Tincture of opium: 10-25 drops every 6 hours
Clonidine:Inhibits intestinal electrolyte secretion • Used in: • Secretory diarrhea • Diabetic diarrhea • Cryptosporiodiosis • Dose: 0.1-0.6mg twice daily oral • Patch: 0.1-0.2mg/day
Octreotide: Somatostatin analog • Stimulates intestinal fluid and electrolyte absorption • Inhibits intestinal fluid secretion • Inhibits release of gastrointestinal peptides. • Given for: secretory diarrheas due to tumors--- VIPomas, Carcinoid, AIDS related diarrhea • Dose: 50-250mcg subcutaneously three times daily.
Octreotide analogs Lanreotide Vapreotide. Octreotide very useful for treating bleeding esophageal varices.
Cholestyramine: • Bile salt binding resin • Used in: • Bile salt induced diarrhea • Intestinal resection • Ileal disease • Dose: 4g once to three times daily
Bulk forming and hydroscopic agents: Carboxymethylcellulose & Calcium polycarbophil– absorb water and stool bulk. Useful in mild chronic diarrhea in patients with irritable bowel syndrome Mechanism of action: Works as a gel to modify stool texture & viscosity to produce perception of decreased stool fluidity.
Others: Clays such as kaolin and other silicates like attapulgite ( magnesium aluminium disilicate) bind water avidly. Kaolin and pectin: useful in mild diarrhea. Calcium channel blockers like verapamil and nifedipine: decrease gut motility, promote intestinal water absorption.
Berberine: • Plant alkaloid. It has: • Antimicrobial activity • Inhibits smooth muscle contraction • Delays intestinal transit by antagonizing effects of acetylcholine. • Chloride channel blockers: • Antisecretory agents. • Calmodulin inhibitors including chlorpromazine and ZALDARINE MALEATE