GI Pharm Flashcards
Antacids used for the treatment of what?
ulcers
What meds are antacids? 3
- Aluminum salts
- Magnesium hydroxide
- Calcium carbonate
MOA: Antacids
- In general how do they work?
- How do they do this? 4
- In general work by neutralizing gastric acid
- Protect gastric mucosa against acute chemical injury
- Bind bile acids and inhibit peptic activity
- Promote angiogenesis in injured mucosa
- Heavy metals suppress H. pylori
- What substances are in magnesium salts?
- Brand names? 5
- Common side effects? 5
- Caution with what?
- Magnesium hydroxide/aluminum hydroxide
- Brand names
- Maalox,
- Alamag,
- Mag-Al,
- Mag-Al Ultimate,
- Mylanta - Common side effects:
- Diarrhea,
- constipation,
- abd cramps,
- N/V
- Hypermagnesemia - Caution with renal insufficiency
Aluminum salts
- Caution with what?
- Can block the intestinal absorption of what?
- Brand names? 2
- Caution in renal insufficiency
- Can block the intestinal absorption of phosphate
- Acid gone
- Gaviscon
Calcium carbonate
- Brand names? 6
- Indications? 2
- Most common side effects? 6
- Separate from other meds by what?
- Brand names
- Tums,
- Maalox regular chewable,
- Calci-chew,
- Rolaids,
- Chooz,
- Alka-Mints - Indications:
- Acid indigestion,
- heartburn - Most common side effects:
- constipation,
- bloating,
- gas,
- N/V,
- abdominal pain,
- xerostomia - Separate from other meds by 2 hours
H2 Blockers indications
3
- Treatment and maintenance therapy of peptic ulcer disease
- Treatment of GERD
- Management of dyspepsia
- MOA of H2 blockers?
2. When should we take these?
- Inhibit acid secretion by blocking histamine H2 receptors on the parietal cell
- Generally dosed to take 30-60 min prior to a meal (if using for acid suppression with meals)
H2 blocker side effects?
2
- Rare, severe adverse events, such as renal and hepatic toxicity
- Myelosuppression
H2 blocker SE: Myelosuppressio. What will you see on the CBC?
4
- Thrombocytopenia
- Neutropenia
- Anemia
- Pancytopenia
Rare CNS side effects with H2 blockers?
Rare cardiac side effects?
Can cause confusion, restlessness, somnolence, agitation, headaches, and dizziness and, with prolonged therapy, hallucinations, focal twitching, seizures, unresponsiveness, and apnea (primarily in the elderly with concomitant renal and/or hepatic failure)
Sinus bradycardia, hypotension, AV block, prolongation of the QT interval, and sinus and cardiac arrest have occurred with the rapid infusion
Cimetidine has some unique side effects such as?
5
- Can rarely cause gynecomastia and impotence
- Polymyositis
- Interstitial nephritis
- Cleared through the P450 system so has multiple drug interactions
- Giving rapidly IV can cause cardiac arrhythmias and hypotension
Absorption and distribution of H2 blockers: 1. How well is it absorbed? 2. Peak serum concentrations occur when? 3. Absorption is reduced by 10-20% if taken with what?
- Well absorbed after oral dosing
- Peak serum concentrations occur within one to three hours
- antacids
What are the H2 blockers?
4
- Cimetidine (Tagamet)
- Ranitidine (Zantac)
- Famotidine (Pepcid)
- Nizatidine (Axid)
What are the Proton pump inhibitors?
6
- Omeprazole (Prilosec, Zegrid)
- Lansoprazole (Prevacid)
- Pantoprazole (Protonix)
- Esomeprazole (Nexium)
- Dexlansoprazole (Kapidex)
- Rabeprazole (AcipHex)
PPI: Indications?
5
Treatment of all acid-related disorders
- peptic ulcer disease
- gastroesophageal reflux disease
- Zollinger-Ellison syndrome
- Treating and preventing nonsteroidal anti-inflammatory drug (NSAID)-associated gastroduodenal mucosal injury
- Eradication of Helicobacter pylori infection
PPIs MOA
Block acid secretion
irreversibly binds to and inhibits the hydrogen-potassium ATPase pump on the parietal cell membrane
PPIs MOA
1. What need to be active for PPIs to work so don’t give other antisecretory meds at the same time?
- The amount of H-K-ATPase present in the parietal cell is greatest after when?
- PPIs should be administered when?
- Parietal cells
- a prolonged fast
- before the first meal of the day
PPIs:
- Onset of action?
- Peak concentration?
- About 1 hour
2. Peak concentration in about 2 hours
PPI’s side effects
3
- Diarrhea
- Headache
- Plus flatulence with Protonix
Drug interactions
- Which PPI has the lowest drug interaction?
- Which drugs are metabolized largely via CYP2C19, and the potential for interactions thus appears to be the greatest among the PPIs?
- Pantoprazole (Protonix)
- Omeprazole (Prilosec, Zegrid)
- Esomeprazole (Nexium)
What is the omeprazole?
Significant interaction between omeprazole and clopidogrel
black box warning
Long term administration of PPIs may increase the incidence of what? 3
- Infections
- Fractures
- Malabsorption issues
PPIs
- Which infections does it increase incidence of?
- Which fracturs?
- What kind of Malabsorption issues? 3
- Infections
- C. difficile
- pneumonia - Fractures
- Hip,
- wrist,
- spine - Malabsorption of
- B12 (check levels)
- Magnesium (check levels esp. with diuretics and digoxin administration)
- Iron
PPI administration:
- Take when?
- What if twice daily dosing is needed?
- Take 30-60 min before first meal of the day
2. If twice daily dosing is needed then take second dose 30-60 min prior to the last meal of the day
Sulcralfate (Carafate)
- What substances are in this drug?
- Prevents what?
- Heals what?
- Sucrose octasulfate-aluminum hydroxide
- Prevents chemical induced mucosal damage
- Heals chronic ulcers
- Sulcralfate (Carafate) MOA?
2. Binds to the ulcer base best at a pH below ___ so should be administered 30-60 min prior to meals
- Stimulates angiogenesis and formation of granulation tissue likely due to growth factor binding
- 3.5
Sulcralfate (Carafate) Cautions?
2
- Due to the combination with aluminum hydroxide do not administer with aluminum containing antacids in patients with renal failure
- Do not administer with citrate containing compounds – increases aluminum absorption by 50X in normal renal function
- Bismuth suppresses what?
2. However, not helpful in the treatment of what?
- Suppresses H. pylori infection
2. Not helpful in treatment of non H pylori induced ulcers
Bismuth MOA?
4
- Inhibition of peptic activity but not pepsin secretion
- May bind to ulcer craters
- Recruits macrophages to the edge of the ulcer crater to promote healing
- May increase mucosal prostaglandin production and mucus bicarbonate secretion
Misoprostol (Cytotec)
- INdicated for what?
- Preg cat?
- What class of drug?
- MOA? 2
NOT A FIRST LINE THERAPY
- Indicated for the prevention and treatment of NSAID induced ulcers
- Pregnancy category X
- Prostaglandin E1 analog
- Enhances mucosal defenses and promote ulcer healing
Not a first line therapy
Black box warning for misoprostol
WHat drug is the Prokinetic?
Metaclopramide
Metaclopramide (Reglan)
- First line therapy for what?
- MOA?
- First line therapy for gastroparesis for no longer than 12 weeks unless benefits outweigh risks
- Improves gastric emptying by increasing gastric antral contractions and decreasing postprandial fundus relaxation
Metaclopramide
3 different drug classes it falls under. What are they?
- Dopamine receptor antagonist
- 5-HT4 agonist
- Weak 5-HT3 receptor antagonist
Metaclopramide (Reglan)
7
- Anxiety
- Restlessness
- Depression
- Hyperprolactinemia
- QT prolongation
Extrapyramidal side effects
- Dystonia
- Tardive dyskinesia
Dangerous drug interactions to avoid with metoclopramide
5
- Antispsychotics
- Droperidol (Inapsine)
- Promethazine (Phenergan)
- Tetrabenazine (Xenzine)
- Huntington’s chorea - Trimetazidine (Vastarel MR)
- Antianginal
More drug interactions to avoid with metoclopramide?
4
- SSRIs
- TCAs
- Atovaquone (Mepron)
- Antimalarial - Metyrosine (Demser)
- Tx symptoms of pheochromocytoma
