Colon Pharm- Fitz Flashcards
GLP-2 analogue
MOA: binds enteric neurons and endocrine cells causing release of trophic hormones that increase mucosal epithelial growth leading to enhanced fluid and nutrient absorption
Teduglutide
Tx for short bowel syndrome
Activates CIC-2:
Increased Cloride secretion-> retention of H2O in lumen–> looser stool
poor systemic absorption
FOUND IN BREAST MILK
Lubiprostone
use for chronic constipation or constipation predominant IBS
Activates GC-C–> increased cGMP–>activates CFTR causing increased Cl secretion and retention of water in lumen
Poor systemic absorption
Black box warning in pediatrics
Linaclotide and Plecanatide
use for chronic constipation or constipation predominant IBS
Voltage- independent inhibition of CFTR causing decreased Cl secretion–>increased absorption of H2O from lumen–> firmer stool
Crofelemer
use for diarrhea due to anti-HIV tx
Synthetic analogue of SS (longer half life)
- decreases 5HT stimulated, cGMP dependent Cl secretion
- Decreases NT/hormone release
- at low doses–> increases motility
- at high doses–>decreases motility
Octreotide
On label: tx of tumurs
Off label: severe diarrhea d/t dumping syndrome, short bowel, vagotomy, AIDs
COX Inhibitor
Decreases prostaglanding synthesis-> decreases cAMP–>decreases Cl secretion–> increase absorption of water from lumen leading to firmer stools
antimicrobial and binds enterotoxins
Bismuth Subsalicylate
Use for prevention and tx of traveler’s diarrhea
Drugs are not absorbed so cause increased retention of water in lumen d/t osmosis–>looser stool
Osmotic Cathartics:
Lactulose, Magnesium Hydroxide, Sodium Phosphate, Polyethylene glycol
used for constipation (ESP when enteric nervous system has been disrupted)
Osmotic Cathartic that decreases plasma ammonia concentrations
Used to tx portal systemic encephalopathy
Lactulose
Bind unabsorbed bile acids to increase water retention
some pathologies cause decreased resorption of bile salts and result in osmotic diarrhea
Bile Acid Binding Resins
cholestyramine and colestipol
Decrease reuptake of 5HT in ECL cells–> increae of 5HT in the synapse–> increase in primary afferent activity–> increase in peristalsis
SSRIs: Fuloxetine, Paroxetine, sertaline
use: constipation predominant IBS
Attract water and increase stool mass
Dependend on normal fxn of the rest of the peristaltic reflex
Bulk Laxatives: Dietary fiber, methylcellulose, psyllium
Unclear Mechanism- thought to stimulate the peristaltic reflex. Possibly d/t irritation
Contact (Irritant) Cathartics: Anthraquinone derivatives (cascara sagrada, danthron, senna), bisacodyl, castor oil
Contact cathartic that works in both small and large intestine
Castor oil
Decrease afferent stimulation via 5HT3 leading to decreased peristalsis
5HT3 antagonist: alosetron
use: diarrhea predominant IBS–ONLY AFTER EVERYTHING ELSE FAILS
Activate presynaptic receptors of IPAN–> increases neurotransmitter release from myenteric neurons leading to increased peristalsis
Increases motility
5HT4 agonists
Tegaserod and Cisapride
Tegaserod: for constipation predominant IBS after all else fails
Cisapride: diabetic gastroparesis when all else fails
Inhibit dopamine action (would inhibit ACh) –> increase actions of ACh in gut–> increase motility throughout entire gut
D2 receptor antagonists: domperidone and metoclopramide
Most effective antidiarrheal drugs:
decrease motility and secretion by actin on mu receptor (agonists)
Opiates: diphenoxylate, loperamide
combo diphenoxylate with atropine to reduce abuse
Use for all types of diarrhea
Antagonists of mu receptor; don’t cross BBB
Results in increased gastric motility
Alvimopan, methylnaloxone
Alvimopan- only short term (increased risk MI)
Methylnaloxone is for long term palliative care (i.e. opioid constipation)
Decrease reuptake of NE from postganglionic sympathetic neurons–> increased activation of alpha2 receptors on presynaptic terminals of postganglionic parasympathetic nerves–> decreased ACh release–> decreased motility
TCAs: Amitriptyline, desipramine
use: diarrhea predominant IBS
Antimuscarinic (Anti-ACh) causing decreased motility
Atropine (combo-ed with diphenoxylate)
Use: anti-diarrheal
Stimulation of motilin receptors on smooth muscle causing activation of MMC
Macrolide Antibx: erythromycin
Use: constipation predominant IBS
Surfactant–> increased mixing of water with stool
Docusate (stool softener)
Lubricating stool softener
Mineral oil
List the prokinetic drugs (act along the entire GI tract)
D2 receptor antagonists (domperidone and metoclopramide)
Macrolides: erythromycin
5HT4 agonists: cisapride
