GI system from Pharm perspective Flashcards Preview

GI pharm > GI system from Pharm perspective > Flashcards

Flashcards in GI system from Pharm perspective Deck (12)
Loading flashcards...

Sympathetic role in GI

relaxes walls at a2, B2
Contracts sphincters at a1


Parasympathetic role in GI

Contracts walls, relaxes sphincters, increases secretions all at M3


What is the predominant tone in GI tract?



dopamine role in GI

modulatory transmitter in ENS. Direct relaxant effect by activating D2 receptors in LES and fundus and antrum. Inhibits Ach release from intrinsic cholinergic neurons by activating pre-junctional D2 receptors


serotonin role in GI

An important transmitter or cotransmitter at excitatory neuron-neuron junctions in ENS (too much=diarrhea)


Opiate role in GI

present in some secretomotor and interneurons in ENS--> gastroparesis. Inhibit Ach release and peristalsis. May stimulate secretion.


Compare and contrast IBS and IBD and recall treatments

IBS: no physical damage. Treat prevailing symptoms. Due to waxing/waning treat with PARTIAL serotonin agonist like tegaserod. TNF and interleukins play a role
IBD: TNFa has pivotol role, tx with TNFa antibodies--> infliximab (start first with glucocorticoids, if refractory then go on to infliximab)


Describe the tx of opiate induced GI dysfunction

Write prescription for narcotic+laxative. Judicial use of opiate antogonists.


AE of octreotide

paradoxical fatty diarrhea


Describe pill-induced esophagitis

usually in older patients (produce less saliva), instructions will say to sit up for a certain amount of time like bisphosphonates, often seen with ER and gel capsule drugs


Explain the role of P-gp and CYP3A in drug bioavailability

Decreased P-gp activity causes increased bioavailability.
CYP3A may be controlled by P-gp


Compare and contrast the effects of antacids, H2, and PPIs on concurrent meds

All 3 increase pH--> decrease in bioavailability of antiretrovirals
Antacids chelate drugs like doxycycline, tetracycline, fluroquinolones
H2 and PPIs can inhibit CYP activity
- H2: cim inhibits 1A2, 2D6, 2C19, 3A4; fam decreases theophylline clearance
- PPIs: substrates for CYP2C19, decrease effectiveness of clopidogrel