Nausea and Vomiting, Constipation, Diarrhea, and IBS Flashcards
What are the causes of nausea and vomiting?
GI irritation Motion Sickness Vestibular Disease Hormone Disturbance Drugs and Radiation Exogenous toxins Pain Psychogenic factors Intracranial pathology
What can result from vomiting?
Dehydration
What are the findings with dehydration?
Increased thirst and dry mouth
Less frequent urination
Tachycardia
Pinching skin takes longer to go down
What are the non-pharmacologic therapies for N/V?
Rehydrate (oral rehydration solutions) Avoid Dairy BRAT diet (24hr fluid diet, Banana, Rice, Apple Sauce, Toast (dry)
What are the pharmacologic therapies for N/V?
5-HT3 antagonists
Dopamine Antagonists
Antihistamines
Cannabinoids
What are the rpharmacological therapies that play a role in the chemo zone?
5-Ht3 antagonists
Dopamine Antagonists
What are the 5-HT3 Antagonists used for N/V?
Ondansetron (Zofran)- most common
Granisetron (Kytril)
Dolasetron (Anzemet)
Ondansetron (Zofran), Granisetron (Kytril), Dolasetron (Anzemet)- MOA and ROA
5-HT3 Antagonists
Antagonism of the 5-HT3 receptor in the chemo-receptor trigger zone
ROA- oral, rectal, IM, IV
Ondansetron (Zofran), Granisetron (Kytril), Dolasetron (Anzemet)- Indications
5-HT3 Antagonists
Treatment and prevention of postoperative N/V
Chemotherapy- induced N/V
Ondansetron (Zofran), Granisetron (Kytril), Dolasetron (Anzemet)- ADRs
HA
Dizziness
Diarrhea
ABD pain
What are the dopamine antagonists used for N/V?
Metoclopramide (reglan)
Trimethobenzamide (tigan)
Phenothiazines- Prochlorperazine (compazine), promethazine (phenergen)
Metoclopramide (reglan), Trimethobenzamide (tigan), Phenothiazines- Prochlorperazine (compazine), promethazine (phenergen)- MOA
Dopamine Antagonists
Antagonist of D2 receptors of the CTZ
At higher doses metoclopramide also blocks 5-HT3 receptors
ALSO PROMOTES GASTRIC EMPTYING AND SMALL INTESTINE PERISTALSIS- PROKINETIC EFFECT
Metoclopramide (reglan), Trimethobenzamide (tigan), Phenothiazines- Prochlorperazine (compazine), promethazine (phenergen)- contraindications
GI- HEMORRHAGE, OBSTRUCTION OR PERFORATION Cautious use in pts w/ depression Pheochromocytoma Seizure Use w/ caution in children
Metoclopramide (reglan), Trimethobenzamide (tigan), Phenothiazines- Prochlorperazine (compazine), promethazine (phenergen)- ADRs
EXTRAPYRAMIDAL EFFECTS
RESTLESSNESS, ANXIETY, DROWSINESS, FATIGUE, HALLUCINATIONS
CV- HTN, HPOTN, AV BLOCK, BRADYCARDIA
AGRANULOCYTOSIS
What is the antihistimine used for N/V?
Promethazine (Phenergen)
Promethazine (Phenergen)-MOA
Antihistamine
Blocks H1-> effectiness appear to be with motion sickness and vestibulochoclear dz
Antagonist of D2 receptors in the CTZ
Promethazine (Phenergen)- ADRs
Dry mouth, dizziness
PARKINSONIAN SYMPTOMS (DYSKINESIA, DYSTONIAS, AKATHISIA)
NEUROLEPTIC MALIGNANT SYNDROME
Blood dyscrasias
Promethazine (Phenergen)- Cautions
BPH
Urinary retention
Glaucoma
What is another agent used for N/V other than antihistamines, dopamine antagonists, and 5-HT3 antagonists?
Cannabinoids (Dronabinol (Marinol)
Dronabinol (Marionol)- MOA and Side effects
MOA is not well defined
SE- drowsiness, sedation, increased appetite
What is dronabinol (marinol) used to stimulate?
Appetite in patients that aren’t eating
What does the normal motility (peristalsis) in the intestines do?
Acts to mix bowel contents thoroughly
To propel them in a caudal direction
What control is the regulation of normal intestinal motility under?
Neuronal and Hormonal
What does the vagus nerve of the intestinal (enteric) system do?
Stimulated peristaltic movements
Relaxes digestive sphincters
Promotes GI secretion
What are the vagus nerve fibers that influence secretion?
Meissner’s plexus
What are the vagus nerve fibers that influence motility?
Myenteric plexus
What are the classes of drugs for GI motility?
Laxatives Antidiarrheal agents Prokinetic Agents Antiemetic agents Antispasmotics
How many bowel movements daily is considered normal?
2-3
What is the medical definition of constipation?
2 or more of the following:
- Straining >25% of the time
- Lumpy or hard stools > 25% of the time
- Feeling of incomplete evacuation >25% of time
- 2 or fewer BM in 1 wk
What are the metabolic causes of constipation?
Hypothyroid
Hypercalcemia
Hypokalemia
Diabetes
What are the GI disorder causes of constipation?
Tumors
IBS
Diverticulitis
What are the neurogenic causes of constipation?
Trauma to brain/spinal cord
CNS tumor
Parkinson’s
Can pregnancy cause constipation?
Yes
What medications cause constipation?
Opiates Ca and Al antacids Iron Calcium channel blockers Clonidine Anticholinergics- antihistamines, antiparkinsonians, TCA
What is the best non-pharmacologic management and prevention of constipation?
DRINK PLENTY OF WATER AND FLUIDS P juices (Pear, prune, peach)
What are the non-pharmacologic management and prevention of constipation?
DRINK PLENTY OF WATER AND FLUIDS
Adequate excercise
HIGH FIBER DIET
What does a high fiber diet include?
Insoluble-shorten intestinal transit time and increase stool bulk (whole grain and bran)
Water soluble fiber- more moist stool and less effect on transit time (fresh fruit and vegetables)
What are laxatives used for?
To hasten transit time in the gut and encourage defecation
To clear the bowel prior too medical and surgical procedures
What are the types of laxatives?
Bulk-forming laxatives Emollients and lubricants Saline Cathartics Osmotic laxatives Stimulant laxatives
What are the bulk-forming laxatives?
Psyllium (metamucil)
Methylcellulose (Citrucel)
Polycarbophil (Fibercon)
Psyllium (metamucil), Methylcellulose (Citrucel), Polycarbophil (Fibercon)- MOA
Bulk forming laxatives
Increases the volume of non-absorbable solid residue with water, distending the colon and stimulation peristaltic activity increasing the rate of colonic transit
Psyllium (metamucil), Methylcellulose (Citrucel), Polycarbophil (Fibercon)-Primary Uses and contraindications
CONSIDERED 1ST LINE FOR BEDRIDDEN OR GERIATRIC WITH CHRONIC CONSTIPATION, GOOD IN PREGNANCY
Contraindication- pts w/ stenosis, ulceration or adhesions, and fecal obstruction
Psyllium (metamucil), Methylcellulose (Citrucel), Polycarbophil (Fibercon)- ADRs
Flatulence
ABD distention
Gastrointestinal obstruction
Psyllium (metamucil), Methylcellulose (Citrucel), Polycarbophil (Fibercon)- drug interactions
BINDS DRUGS & REDUCES ABSORPTION- SEPARATE FROM OTHER MEDICATION ADMIN
Psyllium (metamucil), Methylcellulose (Citrucel), Polycarbophil (Fibercon)- other uses
- The ability of these agents to absorb water makes them useful for RELIEVING SX OF MILD DIARRHEA
- Several months use can RELIEVE SX OF IBS
- LOWERING CHOLESTEROL
If you give metamucil or other bulk forming laxatives first how many hours do you need to wait to give medications?
4 hours
If you give medications first how many hours must you wait to give metamucil or other bulk-forming laxatives?
2 hours
What are the emollient laxatives?
Docusate Sodium (colace)
Docusate sodium (Colace)- MOA
Emollient
Surfactant brings water into stool, facilitates mixing of aqueous and fatty materials within intestine, increase H20 and electrolyte secretion in small/ large bowel
Docusate sodium (Colace)- uses
To avoid straining
After MI, rectal surgery, opiates
1ST LINE PREGNANT WOMEN
Onset 1-3 days
Docusate sodium (Colace)- contraindications
Fecal impaction
Signs and sx of appendicitis
What are the lubricants used as laxatives?
Mineral oil
Mineral Oil- MOA
Lubricant
Coats stool (allows easier passage), inhibits colonic absorption of water
Onset- 6hrs-3 days (oral or rectal)
Mineral Oil- Use and contraindications
Used mainly for prevention (to avoid straining and after MI or rectal surgery)
CHRONIC USE IS DISCOURAGES
CAUTION-AVOID IN ELDERLY, ASPIRATION RISK AND DECREASE ABSORPTION OF FAT-SOLUBLE VITAMINS (DEAK)
May leak from anal sphincter
What are the osmotic agent laxatives?
Lactulose and sorbitol
Lactulose- MOA
Osmotic agent
Disaccharide that is metabolized by bacteria in the colon to low-molecular weight acids = osmotic effect
Not considered a 1st line therapy
Lactulose- Uses and SE
MOST COMMONLY USED IN PTS W/ HEPATIC ENCEPHALOPATHY
Side effects- flatulence, cramps, electrolyte imbalance
Oral dose soften stools in 1-3 days
Sorbital- MOA
Osmotic agent
Monosaccharide creates an osmotic gradient when used as a 70% solution
Hyperglycemia
Oral dose soften stool in 1-3 days
What are the saline cathartics used as laxatives?
Magnesium hydroxide (milk of magnesia) Magnesium sulfate (Epsom salts) Sodium phosphate (fleets enema) Magnesium citrate (citrate of magnesia)
Magnesium hydroxide (milk of magnesia), Magnesium sulfate (Epsom salts), Sodium phosphate (fleets enema), Magnesium citrate (citrate of magnesia)- MOA
Saline cathartics
Mg++ or Na+ salts are POORLY ABSORBED; THEY INCREASE THE WATER CONTENT OF THE BOWEL THROUGH OSMOSIS
Onset- 30min-6hrs (oral), 5-30min (rectal)
Magnesium hydroxide (milk of magnesia), Magnesium sulfate (Epsom salts), Sodium phosphate (fleets enema), Magnesium citrate (citrate of magnesia)- Contraindications
Impaired renal function
Mg and Na accumulation
CHF
No sodium for HTN pts
Caster oil- MOA and use
MOA- metabolized to ricinoleic acid (stimulates secretory pathways)
Decreased glucose absorption
Promotes intestinal motility
Not for routine use
Glycerin Suppository- MOA, Use, ADRs
MOA- osmotic action in rectum Onset <30 min May cause rectal irritation Very safe laxative and can be used in children Intermittent use
Can you use a glycerin suppository in children?
Yes
What are the glycerin/hyperosmotic meds used for laxatives?
Polyethylene Glycol (miralax) Polyethylene glycol (PEG, GoLYTELY)
Polyethylene Glycol (Miralax)- MOA and use
Glycerin/hyperosmotic
MOA- osmotic
Use- 17g mixed in water or juice, usually 2wk duration but chronic is okay
Relatively safe, OK for children
Polyethylene glycol (PEG, GoLYTELY)- MOA
Glycerin/hyperosmotic
Osmotoc agent that causes retention of water resulting in softer stool and more frequent defecation
Polyethylene glycol (PEG, GoLYTELY)- USE
For COLONIC CLEANSING BEFORE DIAGNOSTIC PROCEDURES
Note- 4 liters over 3 hrs, NOT FOR CHRONIC USE. AVOID IN PTS W/ INTESTINAL OBSTRUCTION
What are the stimulant laxatives?
Diphenylmethane derivatives- Bisacodyl (dulcolax)
Anthraquinone laxatives- Senna (Senokot)
Bisacodyl (Dulcolax) MOA
Stimulant laxative
Diphenylmethane derivative
Stimulate nerve plexus of the colon
onset 6-8 hrs PO; 1-6 hrs PR
Bisacodyl (Dulcolax)- Contraindications and ADRs
SHOULD NOT TAKE W/IN 1 HR OF ANTACIDS, MILK OR MILK PRODUCTS
Intestinal cramping
CAN CAUSE FLUID AND ELECTROLYTE INBALANCE
PINK COLORED URINE AND FECES
Long term use- could cause damage to the nerve plexi resulting in deterioration of intestinal function
ATONIC COLON
Senna (Senokot)- MOA
Stimulant laxative
Anthraquinone laxative
MOA- increased peristalsis
Senna (Senokot)- ADRs
YELLOW-BROWN TO RED COLORED URINE
LARGE DOSES CAN PRODUCE NEPHRITIS
Long term use- CAN CAUSE DAMAGE TO THE NERVE PLEXI (resulting in deterioration of intestinal funciton), STONIC COLON
Senna (Senokot)- contraindications
Contraindications- PREGNANCY AND ACUTE INTESTINAL INFLAMMATION
Lubiprostone (Amitiza)- MOA
Chloride-channel activator…works by increasing fluid secretion locally in the small intestine by activating the ClC-2 chloride channel
Lubiprostone (Amitiza)- Side effects and contraindications
Side effects- nausea and diarrhea
Contraindications- INTESTINAL OBSTRUCTION AND PREGNANCY
Methylnaltrexone- MOA
Peripherally acting antagonist of mu
Expensive
Does not cross the blood brain barrier
Reduced the effects of opioids peripherally (not centerally)
What is methynaltrexone specific to?
The cause of constipation. Beneficial if you have an opioid cause constipation
What should be prescribed to diabetics for constipation?
Sugar-free products (metamucil)
60% of diabetics have constipation
No increase in mortality
What should you prescribe to pregnant women with constipation?
Bulk forming laxatives or emollients
AVOID MINERAL OIL, CASTOR OIL, and OSMOTICS
What should you recommend for opiate use?
Exercise, adequate fluid, fiber
What should you prescribe for elderly with constipation?
Bulk forming laxatives, enemas, glycerin, lactulose
“P juices” (pear, peach, prune)
Best to AVOID saline laxative due to potential change in electrolytes
What should you prescribe to kids with constipation?
Usually a change of diet and habits
“P juices “ (pear, peach, prune)
<5 y/o glycerin suppositories, malt soup extract (mix w/ juice or breast milk), dark corn syrup, MOM, bisacodyl
Senna or mineral oil
AVOID stimulants and excessive use of enemas
What is acute diarrhea?
Diarrhea for < 3 days
What is chronic diarrhea?
Diarrhea for >14 days
Is diarrhea usually a healthy response?
Yes
Don’t use symptomatic agents too early
When should you not use anti-motility agents?
IN DYSENTERY OR IF C.DIFF IS POSSIBLE
What does rotavirus consist of? Who does it affect? and how can it be prevented?
Watery diarreah lasting 3-7 days, 1/3 have fever
Nearly every child in US infected by age 5
Vaccine (RotaTeq) approved in 2006 given at 2, 4, and 6 months PO
What are the four clinical groups of diarrhea?
Secretory
Osmotic
Exudative
Altered intestinal transit
What diarrhea is caused by a stimulating substance that either increases secretion or decreased absorption of large amounts of water and electrolytes?
Secretory Diarrhea
Does fasting alter stool volume in secretory diarrhea?
No
How is secretory diarrhea clinically recognized?
By large stool volume
>1L/day with normal ionic contents/osmolality
What diarrhea is described as poorly absorbed substances that lead to retention of intestinal fluids resulting in diarrhea?
Osmotic
How is osmotic diarrhea clinically recognized?
If diarrhea stops when patient does NOT eat
What type of diarrhea is caused by inflammatory disease that discharge mucus, serum proteins, and blood into the gut?
Exudative
What type of diarrhea is due to reduced contact time in the small intestine (intestinal resection or bypass surgery could cause this), premature colon (metoclopramide and erythromycin), and bacterial overgrowth?
Altered intestinal transit
What drugs are known to induce diarrhea
Laxatives Antacids containing Mg Antieoplastics Colchicine NSAIDS Orlistat ABX- clindamycin, broad spectrum ABX Antihypertensives- ACEI Cardiac agents- Digoxin Cholinergics PPIs- esomeprazole H2- Blockers- famotidine
What is the biggest offender for C. Diff?
Clindamycin
What is the presentation for patients with diarrhea?
N/V, ABD pain, HA, fever, chills, Malaise
Weight loss
Dehydration
How can you prevent diarrhea?
Sanitation
Hygiene WASH YOUR HANDS!!!!
Strict food and water handling
What are the non-pharmacologic tx for diarrhea?
- Discontinue consumption of solid foods and dairy for 25 hours (osmotic)
- W/ N/V- mild low residue diet, as BM decrease begin bland diet
- Rehydrate- oral rehydration solutions, LR, D5W, NS
- Maintain electrolytes
What is the biggest concern with diarrhea?
Dehydration
How do you rehydrate a healthy adult?
Any beverage + NaCl source (salted crackers)
How do you rehydrate kids?
Commercial oral rehydration solutions
Pedialyte
Apple juice, chicken broth, sport drinks are DISCOURAGED…. hypertonic and low electrolyte concentration
What are the rehydration rates?
- Up to 2 years: 50-100ml after each loose stool and between if possible
- 2 years or more: 100-200ml after each loose stool and between if possible
- Continue extra fluid until diarrhea cessation
- May need IV fluids for severe dehydration
What is the pharmacologic therapy for antimotility?
Diphenoxylate
Loperamide
Paregoric
Difenoxin
What is the pharmacologic therapy for adsorbents?
Kaolin-pectin mix
Polycarbophil
Attapulgite
What is the pharmacologic therapy for antisecratory?
Bismuth subsalicylates
What is the pharmacologic therapy for anticholinergic?
Atropine
What is the pharmacologic therapy for bacterial replacement?
Lactobacillus
What is the pharmacologic therapy for enzymes?
Lactase
What is the pharmacologic therapy for ABX?
Metroniddazole
Vancomycin
Opiates and Derivates, Loperamide, Diphenoxylate, Paregoric, Difenoxin- MOA
Antimotility
Slow intestinal transit
Prolong contact and absorption
Increase gut capacity
Opiates and Derivates, Loperamide, Diphenoxylate, Paregoric, Difenoxin- Cautions
Addiction potential
Worsen diarrhea if infectious
Lomotil- Onset and Contraindications
Clinical benefit usually w/in 48 hrs
If no benefit in 10 days, change therapy
Contraindications- C. diff or entertoxin
Loperamide (Imodium)- MOA
Acts directly on intestinal muscles to inhibit peristalsis, prolonging transit time
Loperamide (Imodium)- Onset and contraindications
Clinical benefit usually w/in 48 hrs
Contraindications- Pts w/ a fever exceeding 101 F (38.3c), acute ulcerative colitis, ABX associated colitis, and children under 2
Kaolin-pectin, polycarbophil, attapulgite- MOA
Adsorbents
Absorb nutrients, toxins, drugs, and digestive juices
Effectiveness unproven in trials, many do not require RX.
Cholestryamine (Questran)- MOA
Absorbs bile salts and C. diff toxin
Pepto-Bismol-MOA and Onset
Bismuth subsalicylate
Stimulates absorption of fluid and electrolytes across the intestinal wall
Onset- <48 hrs
Pepto-Bismol- Side effects
Not for kids Reyes syndrome
Blackened stool and tongue
Salicylism
Can induce gout attacks in susceptible patients
Pepto-Bismol- Interactions
Anticoagulants and tetracycline; May interfere with radiologic studies.
Octreotide (Sandostatin)- MOA
Antisecretory
Blocks the release of serotonin, direct inhibitory effects
Reduces motility and facilitates water absorption from the gut
Octreotide (Sandostatin)- Use and onset
Official indication- control sx in pts with metastic vasoactive intestinal peptide-secreting tumor associated diarrhea
Off labe use- tx of refractory diarrhea
Onset- 1-3 days up to a week
Octreotide (Sandostatin)- ADRs
BRADYCARDIA
HYPERGLYCEMIA
Atropine- MOA
Anticholinergic
Blocks vagal tone and prolongs gut transit time
Atropine- ADRs and contraindications
ADR-anticholinergic side effects
Contraindicated- glaucoma, prostatic hypertrophy
Lactobacillus-MOA
Bacterial replacement
Restores normal flora and intestinal function
Lactobacillus- ADRs and contraindications
Intestinal flatus
Contraindicated in immuno-compromised patients
Lactase Enzymes-MOA and Use
MOA- replaces lactase enzyme deficiency
Use- only useful in lactose intolerance
Zinc
Substantial data supporting zinc in diarrhea as adjunct to ORS
Reduction of Stool output
Reduction of diarrhea duration
MOA is unknown, possibly action on intestinal ion transport
What type of diarrhea is described as 4-5 loose/watery stools per day w/ cramping, +/- fever, lasting 3-4 days without treatment?
Travelers Diarrhea
What is travelers diarrhea mostly consist of and when does it occur?
> 80% bacterial
>90 occur in the 1st 2 weeks of travel
What are the risks associated with travelers diarrhea?
- Ingestion of contaminated foot or drink
- High risk foods- undercooked veggies, unpeeled fruit, raw/undercooked meat
- Risk- meals eat at home < restaurants
- Age: small children and 21-29 y/o
- Type of infection correlated with destination, season, type of travel
What is the prophylaxis for traveler’s diarrhea?
Dietary counseling
Bismuth subsalicylate (Pepto-Bismol)
ABX- effective but irresponsible prophylaxis, give false sense of security.
Resistance is a huge problem w/ ABX
What is the treatment for traveler’s diarrhea?
Rehydration is key
ABX- Cipro OR azithromycin
Noscomial Diarrhea- C.diff
Hospitalized or recent ABX use
Toxin may be present for several weeks
Handwashing
How do you treat C. diff?
Metronidazole
Vancomycin (orally)
What is characterized by lower abdominal pain, disturbed defecation, and bloating with absence of structural or biochemical explaining factors?
Irritable Bowel Syndrome (IBS)
What are the contributing factors of IBS?
Genetics Motility Factors Inflammation Colonic Infections Mechanical irritation to local nerves Stress
How does IBS present?
- Lower abdominal pain
- Abdominal bloating and distention
- Diarrhea symptoms >3 stools/day- extreme urgency and mucus passage
- Constipation symptoms <3 stools/wk- straining and incomplete evacuation
- Psychological- depression, anxiety
- Urinary sx
- Fatigue
- Dyspareunia
- Concurrent conditions- fibromyalgia, functional dyspepsia, chronic fatigue syndrome
What is the manning diagnosis criteria of IBS?
Chronic Or recurrent abdominal pain >6months with 2 or more of the following:
-Ab pain relieved by defecation
-Ab pain associated with more freq stool
-Ab distention
-Feeling of incomplete evacuation after defecation
Mucus in stools
What is the rome III criteria of IBS
Recurrent abdominal pain or discomfort >3 days/month in the last 3 months associated with 2 or more of the following:
- Relieved with defecation
- Onset associated with change in frequency of stool
- Onset associated with change in form of stool
How do you treat constipation predominant IBS?
Stress management and pt education
Increase dietary fiber and fluid
Next add bulk forming laxative and consider antispasmodics
Add Serotonin-4 agonist (Tegaserod)
How do you treat diarrhea predominant IBS?
Stress management and pt education
Lactose and caffeine free diet as well as avoiding other causative foods
Add loperamide or another antispasmodic
Add 5-HT3 antagonist (Alosertron)