Constipation I
List 2 types of drugs that can cause constipation.
What are NSAIDs, antacids, iron supplements, anticholinergics, antihistamines, laxatives, muscle relaxants, CCBs, and/or opioids?
Mechanism of action for bulk-forming agents (i.e. psyllium, carboxymethylcellulose)
What is the absorption of water and formation of gels in the large intestine?
This distends the intestine and stimulates peristalsis.
List 2 types of drugs that can cause diarrhea.
What are antibiotics, antacids, PPIs, cholinergic drugs, cholinesterase inhibitors, laxatives (osmotic, stimulant), prokinetic agents (metoclopramide), prostaglandins, and/or chemotherapy?
Medication can act as both an antidiarrheal and laxative agent
What are bulk-forming agents (i.e. psyllium)?
MoA: absorbs water and forms gels in the large intestine; this slows passage through the intestine in the setting of diarrhea
List 1 contraindication for administering laxatives.
The major adverse effect for osmotic/saline/hyper-osmotic laxatives (i.e. magnesium/phosphate preparations, polyethylene glycol, lactulose, glycerin suppositories)
What is acute phosphate nephropathy?
Phosphates in high doses as bowel prep can cause this (black box warning).
Class of drugs (or provide an example) that targets somatostatin receptors to hyperpolarize neurons, decreases ACh, and slows peristalsis
What are antisecretory agents (i.e. octreotide)?
Medication that stimulates opioid receptors in the myenteric plexus, resulting in delayed intestinal transit and decreased secretions
What is loperamide [Imodium]?
The current clinical use for mineral oil
What is enema for fecal impaction?
MoA: penetrates and lubricates feces for easier passage; prevents water reabsorption
Surfactants like docusate are NOT useful in what scenario?
What is "once constipation has occurred?"
Mechanism of action for bile acid binders (i.e. cholestyramine, colestipol, colesevelam)
What are anion exchange resins used to bind bile acids?
Large, positively charged molecules that bind to negatively charged bile acids in the gastrointestinal tract
Opioid derivates like Eluxadoline [Viberzi] have a high affinity to agonize _____ receptors.
What are mu or kappa?
Indicated as an antidiarrheal agent for patients with IBS-D
Which type of laxatives can be prodrugs?
What are irritants/stimulants/contacts (i.e. bisacodyl)?
Mu opioid antagonists are only used when . . .
What are "when opioids are in use?"
Antidiarrheal that is contraindicated in patients with a hypersensitivity to ASA/salicylates
What is bismuth subsalicylate (Peptobismol)?
What are 5-HT3 receptor agaonists?