GI Motility 2 Flashcards
Which laxative?
- rapid movement of water into the distal small bowel and colon leads to a high volume of liquid stool followed by rapid relief of constipation
- high doses of osmotically active agents produce prompt bowel evacuation within 1–3 hours
- important that patients maintain adequate hydration by taking increased oral liquids to compensate for fecal fluid loss
Purgatives
- Magnesium citrate
- Sodium phosphate
ADEs of which laxative?
- hyperphosphatemia
- hypernatremia
- hypocalcemia
- hypokalemia
- may lead to cardiac arrhythmias
- may lead to acute renal failure
Sodium Phosphate
In which 4 patients should you not prescribe Sodium Phosphate?
- Frail / elderly
- Renal insufficiency
- Significant cardiac disease
- Unable to maintain adequate hydration during bowel preparation
Which laxative?
- used to clean colon before GI endoscopic procedures
- balanced, isotonic solutions contain an inert, nonabsorbable, osmotically active sugar with sodium sulfate, sodium chloride, sodium bicarbonate, and potassium chloride
- designed so that no significant intravascular fluid or electrolyte shifts occur
Polyethylene glycol (PEG)
Which laxative?
- safe for all patients
- solution should be ingested rapidly (2–4 L over 2–4 hours) to promote bowel cleansing
- treatment or prevention of chronic constipation
Polyethylene Glycol (PEG)
(MiraLAX)
Which laxative?
- Induce bowel movements through direct stimulation of the enteric nervous system and colonic electrolyte and fluid secretion
- may be required on a long-term basis
- Neurologically impaired
- Bed-bound patients in long-term care facilities
Cathartics (stimulant laxatives)
Which laxative?
•Long-term use is controversial
Stimulant laxatives (cathartics)
Which laxative?
- Aloe, senna, and cascara
- Occur naturally in plant
- Laxatives are poorly absorbed and after hydrolysis in the colon, produce a bowel movement in 6–12 hours
Anthraquinone Derivatives
(Laxative Stimulants)
Anthraquinone Derivatives (Laxative Stimulant)
- Chronic use causes what?
- There is concern these agents may cause what?
- Characteristic brown pigmentation of the colon (Melanosis Coli)
- Carcinogenic, but epidemiologic studies do NOT suggest a relation to colorectal cancer
Which laxative?
- Bisacodyl (Ducolax)
- treatment of acute and chronic constipation
- used in conjunction with PEG solutions for colonic cleansing prior to colonoscopy
- induces a bowel movement within 6–10 hours when given orally and 30–60 minutes when taken rectally
- minimal systemic absorption and appears to be safe for acute and long-term use**
Diphenylmethane Derivative
Acute and Chronic therapy w/ opioids may cause constipation due to what mechanism?
Decreasing intestinal motility
Which 3 Opioid Receptor Antagonists (peripherally acting)?
- do not readily cross the blood-brain barrier
- inhibit peripheral μ-opioid receptors without impacting analgesic effects within the central nervous system
- Methylnaltrexone bromide
- Alvinopan
- Naloxegol
Which Opioid Receptor Antagonist?
•approved for the treatment of opioid-induced constipation in patients receiving palliative care
Methylnaltrexone (Relistor)
Which Opioid Receptor Antagonist?
- approved for short-term use to shorten the period of postoperative ileus in hospitalized patients who have undergone small or large bowel resection
- no more than 7 days
- possible cardiovascular toxicity
Alvimopan (Entereg)
Which Opioid Receptor Antagonist?
•Opioid-induced constipation
- Dosage adjustment with renal impairment (CrCl < 60ml/min)
- Avoid use in severe hepatic impairment (Child-Pugh class C)
Naloxegol (Movantik)
