GI Drugs 1 Flashcards
(73 cards)
what are the second generation H2 receptor antagonists?
ranitidine, famotidine and nizatidine; better than the first generation H2 receptor antagonist which is cimetidine because 2nd generation has no anti-adrenergic or CNS adverse effects
motilin in GI peristalsis ↑ GI motility by binding to ______ or _______
- binds directly to the motilin receptor on the muscularis layer
OR - binds to the enteric neuron which then releases acetylcholine that binds to the M1 receptor on the muscularis layer
triple therapy for H. Pylori eradication lasts for ______ days. what are the drugs used in triple therapy
10-14 days
clarithromycin + amoxicillin + PPI
OR
clarithromycin + metronidazole + PPI
what receptors does metoclopramide work on?
- D2 (dopamine) receptor ANTAGONIST
- vagal and central 5HT3 ANTAGONIST
- 5 HT4 agonist
effects confined to the upper digestive tract
why can’t you give misoprostol to pregnant patient?
it has abortifacient effects (cause uterine contractions)
what receptors are involved in the motion sickness cause of vomiting
H1 and muscarinic receptors in cerebellum
describe the mechanism by which prostaglandin ____ is protective
E2; it is coupled to a Gi receptor which DOWNREGULATES the adenylate cyclase activity → ↓ cAMP release → ↓ proton pump
when would you use quadruple therapy for H. pylori eradication?
what are the drugs and how long does this last?
- give quadruple therapy for patients with H. pylori infection in endemic regions where there is macrolide resistant H. pylori
- bismuth subsalicylate (antacid) + metronidazole + tetracycline + PPI
- lasts 14 days
_______ is an analog of PGE1
misoprostol
clopidogrel is converted to the active form via ________
CYP2C19
what are the complications of peptic ulcer disease
- upper GI bleeding
- gastric/duodenal perforation
- gastric outlet obstruction
what drugs are H1 antagonists? what can they be used for?
- lizine: meclisine and cycling
- diphenhydramine
can be used for motion sickness and postoperative emesis
blackening of the stool and tongue is seen with use of what drug?
bismuth subsalicylate (harmless)
are msucarinic (m1) receptor agonists good agents for ↑ GI motility?
no because they dont create a coordinated contraction; for a coordinated contraction want to use a drug that works at the level of the enteric neurons or higher
aprepitant can affect the metabolism of many drugs such as warfarin and oral contraceptives because _________
aprepitant undergoes extensive CYP3A4 metabolism
M___ receptor is repsobiblry for GI motility
M1
why do you give PPI’s as part of the triple therapy for H. pylori infection
- direct antimicrobial properties of PPI’s
- raises gastric pH thus lowers the minimal inhibitory concentrations of antibiotics needed to clear the organism because the ↑ in pH causes the organism to divide and that is when it is most susceptible to destruction
explain the triple therapy for H. Pylori eradication
2 antibiotics + 1 PPI
PPI’s ______ bind to the H/K ATPase pump
irreversibly
how do benzodiazepines help treat nausea? q
- reduce the anticipatory component of nausea and vomiting and thus works on the cerebrum
NO INTRINSIC ANTIEMETIC EFFECTS
misoprostol is an analog of _____
PGE1
all three compounds ultimately activates ______ which then increases the acid secretion into the gastric lumen by ______
protein kinase which then ↑ the activity of the K/H protein pump in the parietal cells: H+ is pumped into the gastric lumen when K is pumped into the parietal cell
how do corticosteroids help treat nausea in patients with metastatic cancer?
- suppression of peritumoral inflammation and prostaglandin production
drugs: dexamethasone and methylprednisolone
extrapyramidal effects are an AE of what drugs
promethazine and droperidol
