Final: Constipation - Drug Info Flashcards

1
Q

When to Refer to PCP

A
  • Age <2 years old
  • Severe symptoms (abdominal pain, significant cramping/distention, N/V, fever)
  • Marked or unexplained flatulence
  • Chronic condition (paraplegia/quadriplegia, [IBD], colostomy)
  • Anorexia/weight loss
  • Bloody or black/tarry stools
  • Marked change in character of stool (e.g., becomes pencil thin)
  • Duration of symptoms >2 weeks or recur over at least 3 months
  • Symptoms that recur after dietary or lifestyle changes
  • No improvement with self-treatment >7 days
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2
Q

Non-pharmacologic Treatment

A

• Balanced diet with F/V/WG
• Daily fiber intake (14 g/1000 kcal), 25g/d W and 38g/d M
• Gradually increase insoluble fiber over 1-2 weeks; may take 3-5 days before effective
• If dietary modification is not effective, may use fiber supplement
- Inulin (FiberChoice®, Metamucil Clear & Natural®)
- Wheat dextrin (Benefiber®)
• Increase fluids to 2 L/day
- Pregnant (extra 300 mL) and lactating women (extra 750-100 mL)
• Bowel training
• Exercise

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3
Q

OTC Pharmacologic Options

A
  1. Bulk-forming agents
  2. Hyperosmotics
  3. Emollients
  4. Lubricants
  5. Saline
  6. Stimulant agents
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4
Q

Bulk Formers, Brands

A
  • Methylcellulose (synthetic fiber) - Citrucel®
  • Polycarbophil (synthetic fiber) - FiberCon®
  • Psyllium (natural fiber) - Metamucil®, Konsyl®
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5
Q

Bulk Formers: Indications

A
  • Patients on low-fiber diets
  • New mothers in the postpartum period
  • Older adults
  • Patients with colostomies, IBS, diverticular disease
  • Prophylactically (surgery)
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6
Q

Bulk Formers: MoA, Onset

A
  • Swell in fluid of small/large intestines, form emollient gels (facilitate passage and stimulate peristalsis)
  • Onset: 12-24 hrs, up to 72 hrs
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7
Q

Bulk Formers: AEs, Counseling

A
  • Abdominal cramping / flatulence / acute bronchospasm (if inhaled)
  • Mix 1 tablespoon and drink with 8 oz of fluid/dose, separate by 2 hours of other medications
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8
Q

Bulk Formers: Interactions, Warnings

A

(separate by 2 hours)
- All interfere w/ absorption of warfarin, digoxin, salicylates, Polycarbophil-oral tetracyclines and fluoroquinolones

  • Avoid if swallowing difficulties, esophageal strictures, or on fluid-restricted diets
    • Hypercalcemia (calcium polycarbophil caplets and renal disease)
    • Dextrose content (concern w/ diabetes)
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9
Q

Hyperosmotics: Brands, MoA

A
  1. Polyethylene glycol (PEG) 3350 (MiraLAX®)
  2. Glycerin (Fleet’s®)

MoA
• Large, poorly absorbed ions or molecules draw water into colon or rectum through osmosis to stimulate BM

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10
Q

PEG 3350: Caution, Onset, AEs

A
  • MiraLAX
    • Short-term/occasional constipation (safe/efficacious) (bowel prep surgery.)
  • Onset: 12-72 hrs, up to 96 hrs
  • Caution in renal disease or IBS
  • Age 17 and above
  • Adverse effects: bloating, abdominal discomfort, cramping, flatulence, >34 g/day may lead to diarrhea and excessive stools
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11
Q

Glycerin: Onset, AE

A
  • Rectal suppository for lower bowel evacuation
  • Available in solid or liquid formulations
  • Onset is quick! (15-30 minutes)
  • Adverse effect: rectal irritation from overdosage
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12
Q

Emollients (stool softeners): Brands, Onset (MoA)

A
  1. Docusate sodium (Colace®): capsule/liquid in varying strengths
  2. Docusate calcium: capsule, 240 mg
  • Onset: 12-72 hrs, 3-5 days

MoA:

  • Anionic surfactants in SI/LI that increase the wetting efficiency of intestinal fluid
  • Facilitate mixture of aqueous and fatty substances to soften fecal mass
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13
Q

Emollients: Combo, LD AE, Counseling

A
  • To prevent straining/painful defecation in patients with anorectal disorders/when straining should be avoided
  • Combine with a stimulant (senna/bisacodyl) as long-term treatment for opioid-induced constipation
  • Increases systemic absorption of mineral oil
  • Larger than recommended doses may cause weakness, sweating, muscle cramps, and irregular heartbeat
  • Counseling: increase fluids to increase softening of stool
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14
Q

Lubricants - Mineral oil (liquid petrolatum)

A
  • Softens feces in colon by coating stool and preventing colonic absorption of fecal water
  • Onset: 6-8 hrs (oral), 5-15 minutes (rectal)

• Adverse effects/concerns:

  • Lipid pneumonia (aspiration into lungs after oral dose)
  • Do not use in <6 years old, pregnancy, immobile or older adults, or those with difficulty swallowing
  • Anal leakage and pruritus (high doses)
  • Immune reaction if reaches lymph nodes (long-term use)
  • Impairs absorption of fat-soluble vitamins

(USE DISCOURAGED! TOO MANY SAFETY CONCERNS)

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15
Q

Saline Laxatives: Forms, MoA

A

• Dosage forms

  • Liquid or solid for oral administration
  • Liquid for rectal administration

• MoA
- Draw water into SI/LI (oral products) or colon (rectal products) by osmosis, increase intraluminal pressure, and promote GI motility

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16
Q

Saline Laxatives: Onset, Brands

A
  • Mg OH: Milk of Magnesia, 30min-6hrs (oral)
  • Mg citrate: Mg Citrate oral solution, 30min-3hrs (oral) and 2-15min (rectal)
  • NaPhos: “Enema” products, 30min-3hrs (oral), 2-15min (rectal)
  • MgSulf: Epsom salts: AVOID!
17
Q

Saline Laxatives: AEs, Patient Ed.

A
  • AEs: abdominals cramping, N/V, dehydration
  • DONT USE if cannot tolerate fluid loss
  • Oral doses of Mg salts -> 8 oz of water after
  • Use at bedtime for occasional constipation
18
Q

Saline Laxative Concerns

A

RECOMMEND MAGNESIUM HYDROXIDE VS SODIUM PRODUCTS

Magnesium products: hypermagnesemia
• Avoid in sodium-, phosphate- or magnesium restricted diets / at risk of magnesium toxicity (newborns, older adults,
renally impaired)

Sodium phosphate products - many issues!
• Hyperphosphatemia, hypocalcemia, hypernatremia
• Use cautiously in renal impairment, sodium-restricted diets, and/
or meds that affect electrolyte levels (e.g., diuretics)
• Contraindicated in heart failure patients
• Avoid enema in megacolon, GI obstruction, imperforate anus, or colostomy
• Max 1 dose in 24 hours, no more than 3 days

19
Q

Stimulants: Brands, MoA

A
  1. Senna (Senokot®)
  2. Bisacodyl (Dulcolax®, Correctol®) - preferred stimulant
  • 2nd line after bulk-formers or PEG 3350 for simple constipation
  • MoA
  • Increase intestinal motility by local mucosal irritation by acting on the intramural nerve plexus of intestinal smooth muscle
  • Also increase secretion of water and electrolytes in the intestine
20
Q

Stimulants: Onset, AEs

A
  • Onset: 6-10 hours after oral, up to 24 hrs. 15-60 minutes after rectal
  • Adverse effects
  • Severe cramping
  • Electrolyte and fluid deficiencies
  • Enteric loss of protein
  • Malabsorption due to excessive hypermotility and catharsis
  • Hypokalemia

• Senna may color urine pink-red, red-violet, or red-brown
- Do not crush or chew or take bisacodyl within 1 hr after taking antacid, H2RAs, PPIs, or milk

21
Q

Opioid-induced Constipation

A

• Chronic users should receive a long-term laxative to prevent and/or treat constipation

• Stimulant laxatives (senna or bisacodyl, +/- docusate or PEG 3350) are most commonly recommended
- Senokot-S® = senna 8.6 mg, docusate sodium 50 mg tablet

22
Q

To Pick a Med

A

• Consider what most mimics normal BMs

  • Bulk-formers closest but may take 72 hrs or longer
  • If faster onset is desired or bulk former is inappropriate/ineffective, PEG 3350 should be tried; consider stimulant if that doesn’t work
  • Use lowest dose and reduce once sx subside
  • Refer to provider after 7 days of non-rx if no benefit
23
Q

Children

A
  • Most products not for < 6 y.o. w/o PCP advice
  • Mild constipation: diet (increase fluids, prune/apple juice) and behavior modification
  • Age 2-5: oral docusate sodium or magnesium hydroxide first, and senna; glycerin or sodium phosphate suppositories if ineffective
  • Age 6-12: methyl cellulose, calcium polycarbophil, docusate sodium, or magnesium hydroxide first, magnesium citrate, senna; glycerin, biscodyl, or sodium phosphate suppositories for quicker onset
24
Q

Elderly

A
  • Review lifestyle modifications and medications first
  • Avoid bulk-formers if dehydrated, very frail, bedridden, or unable to drink fluids; avoid mineral oil and saline laxatives
25
Q

Pregnant/BF

A
  • Dietary measures first
  • Bulk formers or PEG 3350 first
  • Docusate if hard, dry stools
  • Short-term use of senna or bisacodyl also ok
  • AVOID castor oil, mineral oil, and saline laxatives
  • Senna, bisacodyl, PEG 3350, and docusate ok for breastfeeding (minimally absorbed or do not accumulate)