14 - Constipation Flashcards
1
Q
What is constipation?
A
Infrequent and/or unsatisfactory defecation fewer than 3 times per week
2
Q
What are common symptoms that px complain of w/ constipation?
A
- Straining and/or pain
- Passing dry, hard stool
- Passing small stools
- Feelings of incomplete bowel evacuation
- Bloating or decreased stool frequency w/ distention
- Feeling of rectal blockage and abdominal discomfort
3
Q
What is considered normal bowel habits?
A
Can range from 3 BM/day to 1 BM every 3 days
4
Q
What is functional constipation?
A
Chronic constipation not caused by a drug, anatomic, or physiologic abnormality
5
Q
What are some risk factors for constipation?
A
- Female
- Non-white
- Living in rural, northern, or mountainous areas in North America
- Over 65 y/o
- Fewer years of formal education
- Low caloric intake
- Increased number of medications
- Lower socioeconomic status
- Sedentary lifestyle
- Travelling
- Ignoring urge to defecate
6
Q
What are some diseases that cause constipation?
A
- IBS, IBD
- Neurological (stroke, MS, Parkinson’s)
- Diabetes
- Chronic renal failure
- Carcinoma
- Psychiatric
- Anal fissures
7
Q
What are some medications that can cause constipation?
A
- Antacids (aluminum and calcium)
- Anticholinergics
- Iron supplements
- Analgesics
- Antihypertensive agents
- Anticonvulsants
- Antipsychotics
8
Q
What are some lifestyle factors that can cause constipation?
A
- Decreased/inadequate dietary fibre
- Inadequate intake of fluids
- Lack of exercise
- Travel
9
Q
What are red flags for constipation?
A
- Sx lasting longer than 2 weeks (or no BM for 7 days) w/ laxative use
- Blood in stool (dark, tarry); mucous; rectal bleeding; severe pain w/ defecating; fever
- Persistent abdominal pain or severe pain when defecating
- Unexplained weight loss of over 5%
- Family history of colon cancer (esp. if px over 50 y/o)
- Anemia sx (fatigue, lethargy)
- Vomiting
- Under 2 y/o
- Unremitting nocturnal sx
- Recent abdominal surgery
- Chronic illness associated w constipation
- Eating disorder
- Moderate to extreme thirst
- Diarrhea alternating w/ constipation
- Rectal or abdominal mass
10
Q
What can be done to prevent constipation?
A
- High fibre diet w/ adequate fluid consumption (min. 1.5 L/day)
- Routine, private toilet regimen
- Defecating when feeling urge
- Prophylactic laxative use (when taking a constipating medication or have chronic condition associated w/ constipation)
- Daily physical activity (moderate)
11
Q
What is the general tx approach for constipation?
A
- Adjust diet to increase fibre and fluid intake
- Include some form of aerobic exercise
- Pharm intervention used in conjunction w/ lifestyle modification
- Select laxative based on px age, health status, and MOA of product
12
Q
What are some fruits that can be recommended for constipation?
A
Apples, pears, prunes
13
Q
___ can be recommended to children to help w/ constipation because it _____
A
Unbuttered popcorn; builds bulk in the stool
14
Q
What are some non-pharms for constipation in children?
A
- Increase daily dietary fibre (popcorn, green peas, avocado, plums)
- Juice that contains sorbitol
- Toilet routine to try defecation 5-15 mins after each meal
- Biofeedback
15
Q
What is the timeframe to effectiveness for OTC products for constipation?
A
- Agents that soften feces (bulk forming agents, emollients) = 12-72 hours
- Agents that result in soft or semisolid stool (stimulant laxatives) = 6-12 h
- Agents that cause watery evacuation (magnesium citrate, magnesium hydroxide, oral sodium phosphates) = 0.5-3 h
- Enemas = 5-15 mins
16
Q
What is the MOA of bulk forming agents?
A
- Dissolve or swell in fluids of digestive tract by attracting water to hydrophilic sites
- Increase stool weight/volume and frequency
17
Q
What is the first line agent for constipation in most cases?
A
Bulk forming agents b/c are considered dietary supplements instead of laxatives
18
Q
Which px should avoid bulk forming agents?
A
Px w/ dehydration or that are fluid restricted
19
Q
What is the recommended length of tx for bulk forming agents? Onset?
A
- Recommended for short-term use, but can be used long-term for prevention (if non-pharms aren’t enough)
- Onset = 1-3 days
20
Q
What product is a stool softener?
A
Docusate sodium/calcium
21
Q
What is the MOA of stool softeners? Onset?
A
- Helps water in bowel mix w/ fecal mass, causing softening
- Onset = 12-72 hours
22
Q
Are stool softeners used for prevention or tx of constipation?
A
Only prevention
23
Q
When are stool softeners highly ineffective?
A
- Preventing chronic opiate-induced constipation
- If inadequate dietary intake
24
Q
When are stool softeners helpful?
A
Px who should not strain, and those w/ fissures or hemorrhoids
25
What are stool softeners often combined w/ for long term tx of opiate-induced constipation?
Sennosides/bisacodyl
26
How does mineral oil act as a laxative?
- Lubricates fecal material and intestinal mucosa
| - Reduces reabsorption of water from GI tract, increasing fecal bulk
27
What is laxative jelly used for? How long can it be used? What is the dosage?
- For tx of occasional constipation
- Used for max. 1 week
- Dosage = single dose at bedtime
28
What is the difference between lubricants and stimulant laxatives?
- Same onset of action
| - Stimulant laxatives have less side effects, so typically recommended over lubricants
29
When are stimulant laxatives used?
- Acute constipation for short periods of time
| - First line for opiate-induced constipation
30
What is the onset of action for stimulant laxatives? When should they be taken?
- Onset = 6-12 hours
| - Taken at bedtime
31
What are counselling notes about bisacodyl products?
- Enteric coated so shouldn't be crushed or chewed
| - Not to be taken w/ milk, antacids, or PPI's
32
What is the MOA of osmotic laxatives?
Presence of ions draws water into intestine, increasing intraluminal pressure, which applies mechanical stimulus that increases intestinal motility
33
When is PEG 3350 used? For how long? What is the dosing? Onset of action?
- Indicated for short term use in px w/ constipation
- May be used long term as well (6 months)
- May be used for opioid-induced constipation
- Dosing = once daily
- Onset = 48-96 hours
34
What are common side effects of PEG 3350?
- Gas
- Cramping
- Bloating
- Diarrhea
35
What are some counselling tips regarding PEG 3350?
- Avoid other medications w/in 2 hours of use
| - Indicated for adults 18+ only, unless recommended by physician for use in children (commonly recommended in children)
36
What is the safest and most effective product for constipation? Why?
- Glycerin suppository
| - Minimal SE (rectal irritation) and no drug interactions
37
What is the MOA of glycerin suppositories? Onset?
- Osmotic effect and local irritation effect leads to drawing of water into rectum to stimulate BM
- Onset = 15-30 mins
38
What is a counselling tip for glycerin suppositories?
- Moisten w/ warm water before insertion
| - Try to retain as long as possible
39
When can magnesium osmotic products be used? Why?
If px has normal renal function b/c frequently cause diarrhea and electrolyte imbalances
40
Magnesium products should be taken w/ ____ to prevent ______
Water; dehydration
41
When should enemas not be used?
Elderly
42
What should be done if constipation is not relieved w/in 48 hours of treatment?
Try another agent w/ a faster onset of action
43
What is the maximum length of treatment for acute constipation?
1 week
44
When should px be referred after attempting tx for constipation?
- No BM w/in 7 days
- Severe abdominal cramps and/or pain, N/V, rectal bleeding, rectal pain, anal fissures
- Dehydration (if diarrhea occurs)
- If sx last longer than 1 month (chronic)
45
What is the recommended tx for constipation in infants under 1 y/o?
- Increase amount of fluid (best to discuss w/ doctor)
- Pediatric glycerin suppositories to relieve rectal disimpaction (if under 2, then only under pediatrician recommendation)
46
What is the recommended tx for constipation in children 1 year or older?
- Increase dietary intake and fluids (sorbitol)
- First line = PEG, lactulose, sorbital
- Second line = MgOH, heavy mineral oil
47
Is pregnancy an automatic referral for constipation?
No b/c fairly common
48
What is the recommended tx for constipation in pregnancy and breastfeeding?
Non-pharms
- Increase fluid intake
- Increase dietary intake of fibre
- Try to time BM after meals
Can use pharm options to help in the meantime
- First line = bulk forming agent
- If stools remain hard, PEG
- Glycerin suppositories can be used occassionally
49
What is the recommended tx for constipation in the elderly?
- Increase dietary and fluid intake (unless fluid restricted, like heart failure or renal problems)
- Encourage px to establish routine time for BM (5-10 mins after meals)
- Can recommend bulk forming agents if not CI'd (must increase fluid as well)
- Can recommend glycerin suppositories, PEG, or stimulant laxatives (only for infrequent use)
50
What is the first line product for constipation in cancer and palliative px?
Stimulant laxatives
51
When should you refer cancer and palliative px w/ constipation?
No BM in 3 days
52
What is the recommendation for laxative use w/ other medications?
Wait 2 hours before and after taking laxatives to take other medications
53
What are common symptoms of laxative abuse?
- Diarrhea (severe, chronic, watery, frequently at night)
- Abdominal pain, N/V
- Weight loss, muscle weakness
- Electrolyte imbalance
54
What is the tx for laxative abuse?
- Referral
| - If returning to pharmacy after being stabilized, recommend fibre or osmotic laxatives to establish normal BM
55
What are contraindications for bulk forming agents?
- Partial bowel obstruction
- Fluid restricted px
- Suspected fecal impaction
- Dysphagia
- GI strictures
- Throat problems
56
What are common side effects of bulk forming agents?
- Flatulence
- Bloating
- Cramping
- Psyllium = bronchospasm, anaphylaxis
- Polycarbophil = esophageal obstruction, fecal impaction
57
What are contraindications for stool softeners?
- Intestinal obstruction
- Acute abdominal pain
- N/V
58
What are common SE of stool softeners?
- Mild transient nausea
- GI cramps
- Occasional rash
59
What is a contraindication for lactulose use?
Galactose restricted px
60
What are common SE of lactulose, sorbitol, and PEG?
- Flatulence
- Abdominal cramps
- Nausea
61
What is a contraindication for sorbitol use?
Severe cardiopulmonary or renal impairment
62
What is a contraindication for PEG?
Renal disease
63
What is a contraindication for MgOH, Mg citrate, and sodium phosphate?
- Cardiac or renal disease
| - Caution w/ dehydration
64
What are drug interactions w/ MgOH and Mg citrate?
Digoxin and tetracyclines
65
What are common SE for MgOH, Mg citrate, and sodium phosphate?
- Hypokalemia
- Abdominal cramps/pain
- N/V
- Dehydration w/ MgOH
66
What are contraindications for senna and bisacodyl?
- Undiagnosed rectal bleeding
- Signs of intestinal obstruction
- Appendicitis
67
What does bisacodyl interact w/?
Milk, antacids, and PPI's
68
What are common SE for senna and bisacodyl?
- Abdominal pain
- Hypokalemia
- Diarrhea
- Dehydration
69
What is a counselling tip for senna?
May discolour urine red to pink or brown to black
