Final: Constipation - Drug Info Flashcards
When to Refer to PCP
- 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
Non-pharmacologic Treatment
• 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
OTC Pharmacologic Options
- Bulk-forming agents
- Hyperosmotics
- Emollients
- Lubricants
- Saline
- Stimulant agents
Bulk Formers, Brands
- Methylcellulose (synthetic fiber) - Citrucel®
- Polycarbophil (synthetic fiber) - FiberCon®
- Psyllium (natural fiber) - Metamucil®, Konsyl®
Bulk Formers: Indications
- Patients on low-fiber diets
- New mothers in the postpartum period
- Older adults
- Patients with colostomies, IBS, diverticular disease
- Prophylactically (surgery)
Bulk Formers: MoA, Onset
- Swell in fluid of small/large intestines, form emollient gels (facilitate passage and stimulate peristalsis)
- Onset: 12-24 hrs, up to 72 hrs
Bulk Formers: AEs, Counseling
- 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
Bulk Formers: Interactions, Warnings
(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)
Hyperosmotics: Brands, MoA
- Polyethylene glycol (PEG) 3350 (MiraLAX®)
- Glycerin (Fleet’s®)
MoA
• Large, poorly absorbed ions or molecules draw water into colon or rectum through osmosis to stimulate BM
PEG 3350: Caution, Onset, AEs
- 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
Glycerin: Onset, AE
- Rectal suppository for lower bowel evacuation
- Available in solid or liquid formulations
- Onset is quick! (15-30 minutes)
- Adverse effect: rectal irritation from overdosage
Emollients (stool softeners): Brands, Onset (MoA)
- Docusate sodium (Colace®): capsule/liquid in varying strengths
- 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
Emollients: Combo, LD AE, Counseling
- 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
Lubricants - Mineral oil (liquid petrolatum)
- 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)
Saline Laxatives: Forms, MoA
• 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