GI Classes Flashcards
Histamine-2 Antagonists MEDS and prototype
Suffix - tidine
MEDS
● cimetidine (Tagamet)
● famotidine (Pepcid): can be used on children
● nizatidine (Axid)
● ranitidine (Zantac)
PROTOTYPE: Cimetidine
MOA H2 antagonists
(Block release of hydrochloric acid in response to gastrin)
- Selectively block histamine-2 receptor sites
- reduction in gastric acid secretion blocking the production of hydrochloric acid
- reduction in overall pepsin production
Indications of H2 antagonists
- Short-term treatment of active duodenal ulcer, gastric ulcer
- Tx of pathological hypersecretory conditions such as Zollinger–Ellison syndrome
- Prophylaxis of stress-induced ulcers and acute upper GI bleeding in critical patients
- Tx of erosive GERD
- Relief of symptoms: heartburn, acid indigestion, & sour stomach
- Reduce absorption of vitamins and minerals (long term use = deficiencies)
CI and AE to H2 blockers
CI:
- Pregnancy or lactation
- Hepatic or renal dysfunction
AE:
- GI–d/c
- CNS – dizziness, h/a, somnolence (deep sedation), confusion
- Cardiac – arrhythmias, hypotension (not severe)
DDI H2 blockers
Warfarin (increase bleeding), phenytoin, beta blockers (increases antihypertensive
effect), alcohol, quinidine, lidocaine, theophylline (methylxanthine: tx OCD. Caffeine x1000), chloroquine, benzodiazepines (increased sedation), nifedipine, pentoxifylline, tricyclics (TCA: increased sedation), procainamide, and carbamazepine
Extra info on H2 blockers
- Famotidine approved for use in children 1-16 y/o
- Nizatidine has no first-pass mechanism in liver, so is the drug of choice for pts with liver
dysfunction - Cimetidine has been associated with antiandrogenic effects – gynecomastia,
galactorrhea - H2 antagonists slow the metabolism of all the above drugs
Additional AE to Cimetidine
- Gynecomastia, diarrhea, CA, impotence
Antacids MEDS and prototype
(Group of inorganic chemicals that neutralize stomach acid)
- aluminum salts
- calcium salts (Tums)
- magnesium salts (MOM)
- sodium bicarbonate
PROTOTYPE: calcium carbonate
MOA and indications to antacids
MOA:
- Neutralize stomach acid by direct chemical reaction
Indications:
- Symptomatic relief of upset stomach associated with hyperacidity
- prophylaxis for GI bleeding & stress
- adjunct tx of severe diarrhea
- tx certain drug intoxications
CI antacids
- Allergy
- GI obstruction (will cause constipation bc it can be used to tx diarhhea)
- Renal dysfunction ( these meds are metallic in nature, and increased metabolic change)
- Any condition that is exacerbated by electrolyte change (d/t calcium intake)
AE Antacids
- Relate to their effects on acid-base levels and electrolytes
- Calcium carbonate - rebound acidity, hypercalcemia, precipitated chalk – s/e acid
rebound - Magnesium salts - diarrhea, sometimes used as laxatives
- Aluminum salts – constipation, hypophosphatemia (poor at neutralizing acid, cause constipation,
as bind phosphates)
DDI antacids
- Affect the absorption of many other drugs
- Separate from every other drug for at least 2hrs
Proton pump inhibitors (PPI) MEDS and prototype
Suffix: - prazole
MEDS:
● dexlansoprazole (Dexilant)
● esomeprazole (Nexium)
● lansoprazole (Prevacid): has “sprinkles” that can be opened and sprinkled on
food
● omeprazole (Prilosec)
● pantoprazole (Protonix)
(give food 30 min before meal)
PROTYPE: Omeprazole
MOA and indications PPI
MOA:
- Suppress secretion of hydrochloric acid into the stomach
Indications:
- Short-term tx of duodenal ulcers, GERD, erosive esophagitis, gastric ulcer
- Long-term tx of pathological hypersecretory conditions, h. Pylori
- Used When H2 pump is ineffective
AE PPI
- CNS : dizziness, h/a, vertigo, asthenia, insomnia, apathy
- GI : n/v/d, abd pain, dry mouth
- URT : cough, stuffy nose, hoarseness, epistaxis
- Lab : decreased Ca (l/t htsn) /Mg (l/t increased bone loss)
DDI PPI
(increased serum levels/toxicity of first line)
- Benzodiazepines, phenytoin, warfarin
- Ketoconazole, theophylline (decrease levels = less effective)
GI Protectant MED
MED: Sucralfate (carafate)
MOA and indications GI protectants
MOA:
- coat any injured area in the stomach and duodenum to prevent further damage from acid
Indications:
- Prevent further breakdown
- Promote ulcer healing (layer of protections allows it to not be exposed to acid = healing)
CI and AE GI protectants
CI:
- Renal failure (buildup of aluminum may occur)
AE:
- GI : n/c/d, indigestion, gastric discomfort, dry mouth
- CNS :dizziness, sleepiness, vertigo
DDI GI protectant
- Aluminum salts (risk of high aluminum levels/toxicity)
- Phenytoin, digoxin, warfarin, fluroquinolone abx (decreased serum levels of the drugs.
Should be administered sepatately with at least 2 hours between drugs)
Prostaglandin MED
misoprostal
MOA and indications prostaglandin
MOA:
- Inhibits gastric acid secretion and increases bicarbonate and mucous production in the stomach
- Prostaglandin E1 analogue. Used to protect the stomach lining. Primarily used to prevent NSAID induced gastric ulcers
Indications:
- Prevention of NSAID-induced gastric ulcers
- Treatment of duodenal ulcers
CI AE, DDI to Prostaglandins
CI:
- Pregnancy: misoprostol will cause miscarriage in pregnancy. It is an abortifacient.
- Pregnancy Category X
AE:
- GI : n/v/d/c, abd pain, flatulence, dyspepsia, indigestion, gastric discomfort, dry mouth
- GU : miscarriage, excessive bleeding/spotting, cramping, hypermenorrhea,
dysmenorrhea
DDI: none
Digestive Enzymes MEDS and prototype
- pancrelipase (Pancreaze)
- saliva substitute (Aquoral, Salivart)
PROTOTYPE: Pancrelipase
MOA digestive enzymes
Saliva substitute: electrolytes and carboxymethylcellulose to act as thickening agent
Pancreatic enzymes: Replacement enzymes
Indications to digestive enzymes
Saliva supplements:
- Stroke
- Salivary gland disorder (dry mouth)
- Extreme surgery of the head and neck
Pancreatic enzyme supplements
- Common duct problems
- Pancreatic disease
- Cystic fibrosis
CI AE, DDI Digestive enzymes
CI:
- Saliva – CHF, HTN, renal failure (abn absorption of electrolytes, including NA, leading to increased CV load)
- Pancreatic enzymes – allergy to pork
AE:
- Saliva – increased Mg, Na, K absorption
- Pancreatic – n/d, abd cramps
DDI: none
Additional Info on GI meds
- Famotidine is the only H2 blocker approved for use in children.
- PPIs, although not approved for use in children, have been successfully used. Lansoprozole (Prevacid) is the PPI of choice in kids
- Antacids ok in children. 5-15 ml q1-3 hrs prn. CAUTION for ELECTROLYTE IMBALANCE in KIDS
- Older Adult- PPI & H2 blockers linked with B12 deficiency (delayed mentation, numbness/tingling) in OA- pernicious anemia
