Lecture 14: Constipation Flashcards
Constipation
Defined as three or less bowel movements per week that are also accompanied
by straining and difficulty with passage of hard, dry stools
Normal gastric motility
- Ingested food sits in stomach/small intestine for ~ 3 hours
- Food then moves along toward the duodenum
- non-digestable food moves from the small intestine to the large intestine
- fecal matter is stored in the sigmoid colon until defecation
- once fecal mater is in the colon it triggers involuntary
movement that moves the fecal matter into the rectum - once in the rectum
the abdominal wall muscles tighten and the external sphincter relax than
allows the stool to pass
Primary Constipation
- Irritable bowel syndrome
- Slow-transit constipation
- Functional defaction disorders
Secondary Constipation
Metabolic
Medications
Neurologic disorders
Primary Colonic disorders
Metabolic
Hypercalcemia
Hypothyrodism
Medications
Opiates
Calcium channel blockers
Antipsychotics
Neurologic disorders
Parkisons Disease
Spinal Cord Injury
DM
Primary Colonic Disorders
Stricture
Cancer
Anal Fissure
Proctitis
DRUGS THAT CAUSE CONSTIPATION
- Nonsteroidal anti-inflammatory drugs (NSAIDs)
- Antacids
- Anticholinergics (benztropine, glycopyrrolate)
- Iron tablets
- Calcium channel blockers (diltiazem, verapamil)
- Anithistamines (loratadine)
DRUGS THAT CAUSE CONSTIPATION
Opioids (morphine, codeine)
WHO IS MOST AT RISK FOR CONSTIPATION?
- Women
- Non-white ancestry
- Children
- Older adults (>65 years and older)
- Pregnancy (later in the trimester)
- Post childbirth
Hemorrhoids:
blood vessels around your anus that are dilated and
inflamed
Anal fissures
tear in the inner lining of the anal mucosa
Fecal impaction
feces stays in the rectum/ large intestine for so long it
sticks to the lining and is
hard to detach
SIGN AND
SYMPTOMS
Decreased frequency of passing stool Difficulty passing stool Abdominal discomfort Bloating Flatulence Anorexia Dull headache Physical/mental weakness Lower back pain
TREATMENT GOALS
- Relieve constipation
- Reestablish normal bowel function
- Establish dietary and exercise habits
- Promote safe and effective use of laxative products if needed
NON-PHARMACOLOGICAL OPTIONS
Increase daily fiber intake to 25 g for adult women and 38 g for adult men
- Encourage diet change over a period of 1-2 weeks
- Whole grains, wheat bran, fruits and veggies
- Can take up to 3-5 days after changing your diet or taking fiber supplements to see effect in bowel movement
Bowel training: the gastrocolic reflex is strongest in the AM and ~30 minutes post
meal. Trying to have a bowel movement at these times can help promote defecation
as it is consistent with the body’s natural physiologic response
Pharmacological options
Bulk-forming agents Osmotic agents Stool softener/emollients Lubricant Stimulant
Bulk-forming agents
Methylcellulose
Polycarbophil
Psyllium
Bulk-forming agents MOA
increases the mass of stool which causes distension and activates enteric reflexes. This increases GI motility and decreases the amount of time it takes the stool to travel down the colon
Bulk-forming agents PK
Onset: constipation relief can be seen 12-72 hours
Bulk-forming agents Adverse
abdominal cramping, gas, possible intestinal obstruction
Bulk-forming agents
Do not use:
Do not use:
- if enteric reflexes are not functional
- if the cause of constipation is unknown
- patients with intestinal ulcerations, stenosis, or disabling adhesions
WHEN TO SUGGEST USING A BULK FORMING AGENT
Use for short term therapy in the follow situations:
¡ Patients on low-fiber diets
¡ Postpartum period
¡ Geriatric patients
¡ Prophylactically in patients who should avoid straining during a bowel movement
Methylcellulose Dose and Dosing
500mg Caplet
1-2 caplets up to 6 times daily
Methylcellulose Comments
Not recommended in
children < 6 except under
PCP
Calcium Polycarbophil Dose and Dosing
625mg caplet
1-2 caplets up to 4 times daily
Calcium Polycarbophil comments
Not recommended in
children < 6 except under
PCP
Psyllium Dose and Dosing
Powder 3.4g/scoop or
package
1 package or scoop in
8oz of liquid( full glass of water) up to 3 times
daily
Psyllium Comments
Not recommended in
children < 12 except under
PCP
Osmotic agents
- Polyethylene glycol (PEG)
- Magnesium hydroxide
- Glycerin suppository
Osmotic Agents MOA
non-absorbable salts that draw water into the small and large intestine (oral products) or colon (rectal products) though osmosis to stimulate bowel movement
Osmotic Agents- PEG
Onset
Onset: 12-72 hours
Osmotic Agents- PEG
Use
- short term constipation
- Use with caution in patients with renal impairment, use for ages 17+ only
Osmotic Agents- PEG
Adverse effects
electrolyte imbalances and flatulence
Osmotic Agents Dose and directions of use
mix 17-gram packet in 8 oz of liquid once daily
Magnesium Hydroxide Onset
30 mins to 5 hours
Magnesium Hydroxide Dose
400mg/5mL: 30-60 mL
its a suspension
Magnesium Hydroxide Use
short term laxative also used as an antacid
Magnesium Hydroxide Cautions
- Use with caution in patients with renal impairment
- not recommended < 2
years of age
Magnesium Hydroxide Adverse effects
bloating, abdominal discomfort, cramping, and flatulence
Magnesium Hydroxide FYI
prevents the absorption of some antibiotics (specifically tetracyclines) must be spaced appropriately
Stool softener agents
Docusate
Stool softener agents MOA
softens fecal mass by incorporation of water and fat to allow easy passage
Stool softener agents Onset
12-72 hours
Stool softener agents Drug Interactions
Mineral oil
- Do not used in combination with mineral oil because it leads to the absorption of mineral oil
- can lead to toxicity, hepatic and mesenteric lymphoid tissues
Stool softener agents Adverse effects
Generally well tolerated
When to use a stool softener agent
- Prophylaxis to prevent straining
- Prophylaxis to prevent painful defecation or when stool is hard
- Used in combination with stimulant laxatives for opioid induced constipation* (referral to PCP)
Difference between Docusate sodium and Docusate calcium
- Clinically there is no difference as far as efficacy but Docusate sodium is cheaper and more frequently used and available
- Docusate sodium has multiple dosage forms
Docusate sodium Dose and Dosing
Capsules 50mg ; 100mg
50-300mg daily in single
or divided doses typically twice daily
Docusate sodium
Dose of 50-150mg
capsules daily can be
used in children 2-12
Lubricating agents
Mineral Oil
Lubricating agents MOA
Softens fecal contents by coating stool and preventing colonic absorption of
fecal water and lubricates the intestine
Lubricating agents Onset
6-8 hours (oral)
2-15 minutes (rectal)
Lubricating agents Exclusions to self-care
Do not use:
- in children less than 6 years old
- pregnant women
- immobile adults
- patients with difficulty swallowing
Lubricating agents Warnings/Precautions
Risk of lipid pneumonia due to aspiration into the lungs.
To avoid this, advise the patient not to lay down after taking this medication for 30 minutes to an hour
Lubricating agents Drug interactions
Vitamins A, D, E and K
- Impairs the absorption of fat soluble vitamins
- Also docusate
WHEN TO SUGGEST USING LUBRICANT AGENT
Not typically recommended as first line therapy (unless recommended by PCP) as there are better alternatives for constipation available over the counter
Mineral Oil Formulation
Liquid (Oral formulation)
Mineral Oil Adult dosing
1-3 tbsp (15-45 mL)
MDD: 3 tbsp (45 mL)
Mineral Oil CHildren 6-12 dosing
1-3 tsps (5-15mL)
MDD: 3 tsps (15mL)
Mineral Oil Children 2-6 dosing
Not recommended for children under 6 except under advice of PCP
Stimulating Agents
Senna
Bisacodyl
Stimulating Agents-Senna MOA
works in the colon to increase intestinal motility and increase the
secretion of water and electrolytes in the intestine
Stimulating Agents-Senna
Onset
6-10 hours
Stimulating Agents-Senna
Adverse Effects
- can cause discoloration of urine (pink/red/violet/brown)
- abdominal
cramps - diarrhea
- nausea
- vomiting
Stimulating Agents- Bisacodyl MOA
works directly on the smooth muscle in the colon to increase intestinal
motility and increase the secretion of water and electrolytes in the intestine
Stimulating Agents- Bisacodyl Onset
6-10 hours (oral)
15-60 minutes (rectal)
Stimulating Agents-Bisacodyl Adverse effects
abdominal cramps
atonic/Lazy colon (colonstasis) -( w prolonged use)-when there is a lack of normal muscle tone or strength in the colon
vertigo (sensation that everything around you is moving or spinning)
Stimulating Agents-Bisacodyl
Patient Education
- Do not crush break or chew
- Space out from medications that increase gastric pH (H2RA blockers, PPIs,
etc. )
When to suggest using stimulating agents
- Prophylaxis to prevent straining
2. Prophylaxis to prevent painful defecation or when stool is hard
Senna dose and dosing- Adults
Tablets: 8.6 mg sennosides
Starting dose: 2 tablets once daily
MDD: 4 tablets twice daily
Bisacodyl Oral Dose and dosing- Adults
Tablets: 5 mg
Dosing: 1-3 tablets(usually 2) once daily
Bisacodyl Rectal Dose and dosing- Adults
Rectal solid suppository: 10 mg
1 suppository in a single daily dose
Patient Education for Bisacodyl
Avoid using Bisacodyl suppository frequently because it can make the colon lazy and the muscle tone to help push it out is going to be lost
Drug-Drug Interactions
Docusate salts-Mineral Oil
Magnesium hydroxide - Tetracylcine antibiotics: Wait at least 1 hour before administration
Bisacodyl-Drugs that raise gastric pH (ex. PPIs)
Exclusions to Self-Care
- Marked abdominal pain pr significant distention or cramping
- Marked or unexplained flatulence
- Fever
- Nausea/Vomiting
- Paraplegia or Quadriplegia
- Daily laxative use
- Unexplained changes in bowel habits, if accompanied by weight loss
- Blood in stool, or dark or tarry stool
- Any bowel symptoms that persist for 2 weeks or recur over period of at least 3 mths
- Any symptoms that recur after dietary/lifestyle changes, or laxative use
- History of IBD
- Anorexia
Clinical presentation: CHildren
- Defined as difficulty or delay in having a bowel movement over a period of 2
weeks+ - Caused by many different factors such as emotional distress, febrile(symptoms of fever), chronic
medical conditions, family conflict, diet changes, etc. - Mild constipation is usually relieved with diet or behavioral changes alone
SPecial Ops- Children
- 2-6 years old: oral docusate, magnesium hydroxide, senna; rectal glycerin, or
sodium phosphate products - 6-12 years old: methylcellulose, docusate, mineral oil, magnesium hydroxide,
senna, bisacodyl or castor oil; rectal glycerin, or sodium phosphate products - PEG is not approved for children <17 years of age
SPECIAL POPULATIONS: OLDER ADULTS
- At greater risk of constipation due to age related dietary changes such as reduced fiber and fluid intake, decreased physical activity, polypharmacy and
presence of comorbidities - Preform a medication history and recommend lifestyle changes first
- First line: bulk forming agents or PEG (for faster onset)
For older adults Patient Education
- Stool softeners are helpful in older adults with annal fissures or hemorrhoids
¡ Avoid: mineral oil due to risk of aspiration and use osmotic agents with
caution due to risk of fluid and electrolyte depletion and drug drug
interactions
SPECIAL POPULATIONS: PREGNANCY
Effects up to 1/3 of pregnant women during and post pregnancy
-Due to compression of the colon, increased progesterone levels, low fluid/fiber intake
and constipating effects of iron and calcium in prenatal vitamins
- Recommend lifestyle changes first
- First line: bulk forming agents, stimulating agents, docusate, PEG
- Avoid lubricating agents like mineral and castor oil
FYI abt mineral oil
castor oil has been associated with uterine contraction and rupture, DO NOT USE and mineral oil may be associated with decreased maternal absorption of fat soluble vitamins which may cause adverse maternal and neonatal effects