Diarrhea Pharm Management Flashcards
Opiates and their derivatives
2 types
Peripheral action:
Loperamide (Imodiumâ) – OTC
Central + peripheral action:
Diphenoxylate + atropine (Lomotilâ) - prescription
Loperamide
dose
duraiton
role
Dose: 4mg, then 2mg after each bowel movement (max 16mg/day)
Duration: recommended not to be used for
more than 2 days (however, can be used longer in some patients with chronic diarrhea)
Role: moderate to severe diarrhea
Children:
◦ Avoid in children <2 years (see dosing in Drug Table
in Minor Ailments chapter for dosing in children)
Loperamide
AE
contra
Adverse effects: abdominal cramps, dry mouth,
drowsiness, constipation
Safe in pregnancy and breastfeeding
Avoid in CDI
Contraindications: acute dysentery (high fever,
bloody stools), liver failure
C difficile infections, need to treat the infection
Dont want to use loperamide that can keep infeciton in
OTC
Diphenoxylate + atropine
dose
duraiton
role
Combined with atropine (anticholinergic) to
further decrease GI motility, also prevent
abuse.
Dose: 2.5-5 mg 3-4 times daily (max 20mg/d)
Role: moderate to severe diarrhea
Less effective than loperamide
Atropine helps avoid abuse
Diphenoxylate + atropine
AE
contra
Adverse effects: dry mouth, blurry vision, urinary retention, constipation ◦ overdose – atropine poisoning Avoid in CDI Contraindications: see loperamide, also caution with use in elderly (anticholinergic effects), children Avoid in pregnancy/breastfeeding
Adsorbent Agents
name of pdt
role
dose
Attapulgite (Kaopectateâ, Fowlers â) Adsorbs water, nutrients, toxins, bacteria, (8x weight) Role: mild diarrhea. May not be as effective as loperamide Well tolerated Dose: 1200 – 1500 mg after each liquid bowel movement (max 9 g/day) Avoid in children under 2y
Hydrophilic Bulking Agents
name of pdt
role
dose
Psyllium
Mechanism in diarrhea includes absorbing liquid to
create firmer stools.
Role: mild diarrhea
Dose: 1 tsp (5 – 6 gm) twice a day
Also be cautious if product combined with other
laxatives
Antisecretory Agents
name of pdt
role
dose
Bismuth subsalicylate
Mechanism not well understood
◦ bismuth: antimicrobial, ¯ attachment of bacteria to GI
epithelium; salicylate: antiinflammatory/antisecretory
Role: mild to moderate diarrhea, prevention or
treatment of Traveler’s Diarrhea*
Dose: 524 mg (ie 2 tabs or 30 ml) every 0.5 – 1
hour prn (max 4.2 g/day)
Dose prevention of Travelers Diarrhea*: 524 mg QID, start 1 day before travel and continue until 2
days after travel
Antisecretory Agents
AE
Bismuth subsalicylate con’t
Adverse effects: black tongue, black stools, tinnitus
Avoid if salicylate allergy
Drug interactions: oral anticoagulants, other
salicylates, methotrexate
Avoid in children <2 years (be careful for Reyes
syndrome)
Caution in pregnancy, breastfeeding (from the
salicylate component)
Swelling in brain and live r(like aspirin which is a salicylate)
Zinc supplementation:
role
dose
◦ Used in developing countries to treat childhood
diarrhea
◦ ↓ severity & duration of diarrhea
◦ Recommended by WHO and UNICEF
◦ 20 mg daily x 10 – 14 days (use 10 mg if less than 6 months of age)
Prescription drugs to treat diarrhea
Cholestyramine
◦ Lipid lowering agent
◦ Mechanism in diarrhea is that it can bind bile acids
◦ Role: treat diarrhea from bile acid malabsorption
◦ Dose: 4 gm daily or bid for bile acid induced
diarrhea
◦ Caution drug interactions as it may bind drugs (for example digoxin). Administer other drugs 1 hour
before or 4 – 6 hours after cholestyramine.
◦ Another options is colesevelam (Lodalis®), another lipid lowering agent
Antibiotics may be needed to treat:
◦ CDI ie metronidazole, vancomycin
◦ Prevent/treat traveler’s diarrhea* ie flouroquinolones,
azithromycin, rifaximin
Note: empiric antibiotics not usually recommended for
acute diarrhea (other than identified above) because often self-limiting and concerns with antibiotic resistance
Octreotide
◦ Somatostatin analogue
◦ Role: diarrhea from neuroendocrine tumors (ie
carcinoid etc)
◦ Also helps with other chronic diarrhea from short
bowel syndrome, chemotherapy and others
Which antidiarrheals do we use for acute
diarrhea?
mod to severe
mild to mod
mild
Choosing among the OTC antidiarrheals
◦ Moderate to Severe - loperamide
◦ Mild to Moderate – bismuth
◦ Mild – attapulgite or psyllium
Note: Most cases of mild may only need symptomatic and ORS,
antidiarrheals usually NOT needed
Note: Patients with severe diarrhea or with red flags should be
referred to their physician/health care provider
Treatment of Chronic Diarrhea
Treat specific cause Discontinue drugs that may be adding to diarrhea if possible Non-pharmacologic (ie diet) Maintain hydration Loperamide or adsorbents are options Prescription drugs to treat diarrhea from specific causes
Pregnancy/Breastfeeding
which ones can be used
Antidiarrheals Adsorbents Loperamide Avoid diphenoxylate/atropine, avoid bismuth subsalicylate
Probiotics
used in?
efficacy in diarrhea
Bacteria or yeast ◦ Includes: Lactobacillus sp, Bifidobacteria, Saccharomyces, others ◦ Most commonly studied species Not PRE-Biotics ◦ Complex sugars to fuel healthful bacteria MOA: ◦ Normalize gut flora
Used in:
◦ Diarrhea prevention and treatment, infectious
diarrhea, travelers diarrhea (prevention and
treatment), antibiotic-associated diarrhea, and IBS
Efficacy in Diarrhea
◦ Fairly good evidence to support use in above
conditions
Multiple systemic reviews
Probiotics for children
Efficacy in the treatment and prevention of
childrens diarrhea
◦ Meta-analysis (children up to 5 years)
Decreased duration of diarrhea by 0.8 days
Greatest effect with Lactobacillus products
◦ Significant amount of evidence for use in children
Probiotics
Dose
supplied in?
◦ Depends on strain used
◦ Expressed as colony forming units (CFU) – generally anything <10^6 not considered effective
◦ Often used 10^9 to 10^10 in studies
Yogurt want to make health claim, need to have 10^9 of lactobacilli
Supplied
◦ Functional foods with added probiotics
ie fermented dairy products like yogurt
◦ No labeling requirements for yogurt – no minimum
amount required, however, if health claim must
have 10^9
Probiotics
admin
Administration: for probiotic supplements capsules, etc
◦ Stability issues with various products – some
require refrigeration
◦ Usually given on empty stomach – sensitive to
stomach acid and bile
Lactobacillus and S. boulardii – more resistant to gastric acid may be enteric coated or microencapsulated
Note: separate administration of antibiotics by 2 hours.
How to Choose a Probiotic
Determine the type of probiotic strain that is needed
to treat the condition.
Look for genus, species and strain: For example:
◦ Genus: Bifidobacterium
◦ Species: longum
◦ Strain: R0157
What is the evidence? What is the level of evidence?
