Diarrhea.Constipation.IBS.pptx

Diarrhea, Constipation, and Irritable Bowel Syndrome (IBS) Justin Kirby, PharmD, BCACP, NBC-HWC PHPR 2813: Pharmacotherapy I Objectives • Identify the common causative organisms of bacterial and viral infectious diarrhea. • Differentiate acute from chronic diarrhea, in terms of onset and duration...

Diarrhea, Constipation, and Irritable Bowel Syndrome (IBS) Justin Kirby, PharmD, BCACP, NBC-HWC PHPR 2813: Pharmacotherapy I Objectives • Identify the common causative organisms of bacterial and viral infectious diarrhea. • Differentiate acute from chronic diarrhea, in terms of onset and duration of symptoms. • List the five therapeutic goals in the treatment of diarrhea. • List factors correlated with the prevention of diarrhea. • Discuss the various drug categories used to treat diarrheal attacks. Objectives • Identify common lifestyle causes of and medical conditions that may lead to constipation. • List common drugs that may cause constipation. • List three general classes of laxatives and their expected onset of effect. • Discuss the proper management of constipation in terms of dietary modification and preferred laxative use. • Discuss therapeutic agents used to treat opioid-induced constipation. Objectives • Define irritable bowel syndrome (IBS), list the manifestations of IBS, and cite its underlying pathophysiologic causes. • Differentiate between constipation- and diarrheapredominant IBS in terms of treatment options. • List drug classes used in the treatment of pain associated with IBS. Diarrhea: Introduction • Troublesome discomfort that affects most individuals at some point in their lives • Usually begins abruptly and subsides within 1-2 days without treatment • Classified as • Acute (<14 days duration) • Persistent (>14 days) • Chronic (>30 days) Diarrhea: Introduction • Definition: Increased frequency and decreased consistency compared with an individual’s normal bowel pattern • Variable between individuals • May be associated with a specific disease of the intestines or secondary to a disease outside the intestines Diarrhea: Introduction • 4 broad clinical groups: • Secretory-Increased secretion or decreased absorption of water • Osmotic – poorly absorbed materials that retain water • Exudative- Usually caused by inflammatory diseases of the bowel which produce mucus • Altered Intestinal Transport – usually caused by bacterial overgrowth or short gut syndrome Diarrhea: Epidemiology • Varies between developed vs. developing countries • Illness is not reported regularly to the CDC • Estimated 25% of Americans experience acute diarrhea annually • Much greater impact on illness and death, especially among children, in developing countries • Most cases of acute diarrhea are caused by food or waterborne viruses, bacteria, or protozoa and are self limiting • Shigella, Salmonella, Campylobacter, Staphylococcus, and E. coli are typical causative bacterial organisms. Norwalk and rotavirus are typical viral agents Prevention of Diarrhea • Environmental hygiene practices can prevent transmission • Hand washing, proper food/water handling/storage • Controlling the primary condition is necessary if diarrhea is secondary to another condition • Antibiotics and bismuth subsalicylate are advocated to prevent traveler’s diarrhea, along with avoidance of drinking untreated water and eating fresh foods while traveling Prevention of Diarrhea • Vaccines • Oral cholera vaccine (Vaxchora®) is recommended for people traveling to an endemic area and is key in controlling infectious diarrhea in developing countries • Can reduce risk of severe diarrhea by about 90% • Vaccines for typhoid and rotavirus have been developed to reduce childhood morbidity and mortality in developing countries and the US Treatment of Diarrhea • Goals: • Manage diet • Prevent excessive water, electrolyte, and acid-base disturbances • Provide symptomatic relief • Treat curable causes • Manage secondary disorders causing diarrhea Diarrheal Management • Must be viewed as a defense mechanism for ridding the body of harmful substances or pathogens • The correct response is not to stop diarrhea at all costs • Dietary management is a first priority in treatment • Feeding should continue in children with acute bacterial diarrhea • Other groups have insufficient data to support continued feeding Diarrheal Management • Rehydration and water maintenance are primary treatment goals until the diarrheal episode ends • In volume depleted patients, replacing water and electrolyte composition to normal is the goal • Most patients do not develop volume depletion and only require maintenance • If vomiting and diarrhea are not severe, enteral feeding is preferred • Due to the negative effects of hyponatremia, hospitalization and IV fluids are necessary to correct fluid and electrolyte deficits in severe dehydration • Oral solutions are still strongly recommended when possible Diarrheal Management Diarrheal Treatment Options • Opiates and derivatives • Includes diphenoxylate with atropine (Lomotil©), loperamide (Imodium©), and paregoric • Delay transit of intralumin contents, increase gut capacity, and prolong contact and absorption • Risk of dependence • If diarrhea persists for >48 hours after loperamide initiation, further medical investigation is warranted Diarrheal Treatment Options • Adsorbents • For symptomatic relief; Non-toxic, often available OTC, variable efficacy • Polycarbophil (Fibercon©) • Antisecretory agents • Includes bismuth subsalicylate (Pepto-Bismol©), somatostatin (Octreotide©) • Octreotide is given via parenteral route and is effective against diarrhea caused by abdominal malignancies and chemo-induced diarrhea Diarrheal Treatment Options • Miscellaneous products • There has been no data to support the use of probiotics in treating diarrhea • Anticholinergic drugs (atropine) block vagal tone and prolong gut transit • Value in controlling diarrhea is questionable and limited due to side effects • Lactase enzyme products are helpful for patients experiencing diarrhea secondary to lactose intolerance Monitoring • Constitutional symptoms should improve in 24-72 hours • Patient should self monitor for changes in frequency and character of bowel movements on a daily basis; If hospitalized, clinicians should monitor serum electrolytes daily • Acute, non-severe, diarrhea should completely resolve in 3-7 days and is usually managed in the outpatient setting • Elderly patients, those with comorbidities, and infants may require hospitalization for rehydration • In severe diarrhea, hospitalization may be required with fluid volume stabilization being the most important outcome while underlying causes are addressed Constipation • Common complaint among the general population • Generally defined by the American Gastroenterology Association (AGA) as difficult or infrequent passage of stool • May be further defined as fewer than 3 bowel movements per week, but “normal” frequency of bowel movements is not well established and can vary greatly person to person • Considered chronic if symptoms last for at least 3 months Constipation Epidemiology • Prevalence depends on the definition used and whether the condition is self or provider-reported • Chronic constipation is estimated to affect about 15% of the adult population worldwide • Much more common in women (2.4x more likely) and the elderly • Associated factors include inactivity, lower socioeconomic class, lower income, non-white race, symptoms of depression, and history of physical or sexual abuse Constipation Pathophysiology • Can be primary (idiopathic) or secondary • Primary constipation can be divided into 3 categories • Normal transit: normal GI motility and stool frequency but may experience difficulty evacuating, passage of hard stools, or bloating/abdominal discomfort • Slow transit: Abnormality of of GI transit time that leads to infrequent defecation • Pelvic floor dysfunction (disordered defecation): muscles or sphincter contract during defecation instead of relax and impede evacuation of stool Constipation Causes Constipation Causes Constipation Presentation Constipation Treatment • Major goals are to relieve symptoms, reestablish normal bowel habits, and improve quality of life Constipation Treatment • Nonpharmacologic Therapy • Dietary modification to gradually increase fiber intake to 20-30 grams per day • Fruits, vegetables, and cereals have high fiber content • Optimized fiber intake for 1 month is a proper trial • Some patients will see effects in 3-5 days • Ensure proper fluid intake accompanies increased fiber intake! • 1 oz/kg (body weight)/day; Fiber + No Water = CONCRETE Constipation Treatment • Nonpharmacologic Therapy • Sometimes surgical intervention is necessary if patients have an obstruction or malignancy • Pelvic floor retraining therapy in patients with muscular dysfunction • 65-80% effective • Electrical stimulation is a minimally invasive technique that has been used for treatment of refractory, chronic constipation. Clinical data is limited. Constipation Treatment • Pharmacologic Therapy • 3 types of laxatives • Those causing softening in 1-3 days • Those that results in semifluid stool in 6-12 hours • Those causing watery evacuation in 1-6 hours • Probiotics have shown promise in increasing stool frequency Constipation Treatment Draws water into the stool Surfactant agents that mix aqueous and fatty material in the GI tract Constipation Treatment Amitiza Linzess Trulance Relistor Movantik Symproic Irritable Bowel Syndrome (IBS) • The most commonly diagnosed GI condition • Characterized by chronic abdominal pain and altered bowel habits in the absence of any organic cause • 10-12% of the population of North America • 2:1 female predominance Irritable Bowel Syndrome (IBS) • Exact pathophysiology is still being investigated • Likely results from altered somatovisceral and motor dysfunction of the intestine from a variety of causes • Known factors contributing to alterations in signals affecting visceral hypersensitivity are genetics, motility factors, inflammation, colonic infections, mechanical irritation to local nerves, and other psychological factors • The enteric nervous system contains a significant percentage of the body’s 5HT receptors • 5-HT3 and 5-HT4 are in the gut and are responsible for secretion, sensitization, and motility IBS Clinical Presentation IBS-D IBS-C IBS Treatment • Based on the predominant symptoms and their severity • Milder, less frequent episodes can be managed through lifestyle changes • Dietary restrictions, higher-fiber diet, physical activity (mobility = motility), and relaxation techniques • More persistent disease may require as-needed uses of various antidiarrheal or antispasmodic agents • Most severe forms will call for pharmacological agents IBS-C Treatment • Dietary fiber may be beneficial • Begin w/ 1 TBSP with 1 meal per day increasing to 2-3 meals per day • Psyllium or PEG laxatives may also be used • When lifestyle modifications alone do not provide control, the Guanylate Cyclase-C agonist, Linzess© (linaclotide), should be used • IBS-D Treatment • Avoidance of certain food products (caffeine, alcohol, artificial sweeteners) may be necessary. Lactose intolerance should be considered. • Loperamide, which decreases intestinal transit, enhances water and electrolyte absorption, and strengthens rectal sphincter tone, may be used in patients who have persistent symptoms following dietary modifications • Should be used in urgent or necessary situations only • Typically caused by excessive 5-HT3 receptor stimulation • Can be treated by 5-HT3 receptor antagonist alosetron (Lotronex ©) (on REMS) • Only approved for women with IBS-D with symptoms >6 months IBS-D Treatment • Eluxadoline (Viberzi©) and rifaximin are approved for use in IBS-D • Eluxadoline is a μ-opioid receptor agonist and rifaximin is an antibiotic recommended for the treatment of traveler’s diarrhea • Tricyclic antidepressants have shown some benefit in IBS-D with moderate to severe pain • Duloxetine (SNRI) showed improvement in symptom severity and quality of life in a 12-week trial References Fabel PH, Shealy K. Diarrhea, Constipation, and Irritable Bowel Syndrome. In: DiPiro JT, Yee GC, Posey L, Haines ST, Nolin TD, Ellingrod V. eds. Pharmacotherapy: A Pathophysiologic Approach, 11e. McGraw Hill; 2020. Accessed January 06, 2022. https://accesspharmacy.mhmedical.com/content.aspx ?bookid=2577&sectionid=219310177 Diarrhea, Constipation, and Irritable Bowel Syndrome (IBS) Justin Kirby, PharmD, BCACP, NBC-HWC PHPR 2813: Pharmacotherapy I