Drugs Impacting Acid And H. Pylori Flashcards
Chest pain: GERD vs. MI
GERD:
- Heartburn, belching, chest pain
- Worse after eating
- Worse at night when lying down
- NOT worse with physical activity
MI:
- Chest pain, nausea, dyspnea, diaphoresis, radiating pain to jaw/left extremity
- Pain precipitated by and WORSE WITH exertion
Proton Pump Inhibitor (PPI) Drugs (first and second generation: 6)
First generation:
1. Omeprazole
Second generation:
- Esomeprazole
- Lansoprozole
- Pantoprozole
- Rabeprozole
- Dexlansoprazole
H2 Receptor Antagonists (first and second generation: 4)
First generation:
1. Cimetidine
Second generation:
- Famotidine
- Nizatidine
- Ranitidine - REMOVED FROM MARKET DUE TO PRESENCE OF CARCINOGEN (NDMA)
Antacids/Acid Neutralizers (single agents and mixed preparations: 6)
Single agents:
- Aluminum hydroxide
- Calcium carbonate
- Magnesium hydroxide
- Sodium bicarbonate
Mixed preparations:
- Aluminum hydroxide/magnesium hydroxide (Mylanta)
- Calcium carbonate/magnesium hydroxide (Rolaids)
Proton Pump Inhibitors (MOA, PK, Pregnancy, Indications)
MOA: Prodrugs are activated in acidic environment. Covalently bind to and irreversibly inhibits the parietal cell H+/K+-ATPase proton pump.
PK: Onset 1 hour. t1/2: 30-60 minutes. Duration: less than 3 days
Pregnancy: N/A
Indications: PUD, GERD, esophagitis, gastric hypersecretion, and gastritis
Proton Pump Inhibitors (ADRs, Considerations, DDIs)
ADRs: headache, abdominal pain, nausea, vomiting, diarrhea, flatulence
Considerations: may cause B12 DEFICIENCY and hypomagnesemia. Increases FRACTURE risk. Need to taper to avoid rebound acid hypersecretion. Ask patient to take other meds 2 hours prior to PPI.
DDIs:
Decreases: cephalosporin abx, B12, ketoconazole, iron salts
Increases: digoxin, voriconazole
H2 Receptor Antagonists (MOA, PK, Pregnancy, Indications)
MOA: Reversibly and competitively inhibits the binding of histamine to the H2 receptor. Stops H+ secretion. Famotidine is the most potent of the class.
PK: Onset 1 hour. t1/2: 2-3 hours. Duration: 13 hours.
Pregnancy: N/A
Indications: PUD, GERD, esophagitis, gastric hypersecretion, indigestion, gastritis, heartburn
H2 Receptor Antagonist (ADRs, Considerations, DDIs)
ADRs: headache, dizziness, diarrhea, TOLERANCE.
Cimetidine- GYNECOMASTIA, inhibits CYP P450.
Considerations: Have patients take other meds 2 hours before H2 receptor antagonist.
DDIs:
Decreases: Atazanavir, B12, ketoconazole, iron salts
Increases: Warfarin, procainamide
Acid Neutralizers (MOA, PK, Pregnancy, Indications)
MOA: Weak bases neutralize HCl to salt and water
PK: Onset variable. t1/2: 2-4 hours. Duration: 20-180 minutes.
Pregnancy: N/A
Indications: esophagitis, indigestion, heartburn, calcium prophylaxis treatment for OSTEOPOROSIS/OSTEOPENIA in postmenopausal women
Acid Neutralizers (ADRs, Considerations, DDIs [levels and effectiveness])
ADRs: can cause rebound acid
Sodium bicarbonate - fastest reaction: flatulence/bloating from CO2 generation, NaCl absorption can result in fluid retention (caution in CHF and HTN)
Calcium carbonate: flatulence/bloating from CO2 generation, CONSTIPATION, MILK-ALKALI SYNDROME- excess calcium and metabolic alkalosis
Aluminum hydroxide - slow reaction: CONSTIPATION
Magnesium hydroxide - slow reaction: DIARRHEA
Considerations: Ask patients to take other meds 2 hours before antacid.
DDIs:
Decreases levels: eltrombopag, ketoconazole, clofazimine
Decreases effectiveness: tetracyclines, levothyroxine, allopurinol
GABA-B Agonist - Baclofen (MOA, PK, Pregnancy, Indications)
MOA: GABA- B agonist suppresses transient LES relaxation and prevents reflux at rest by inducing inhibitory interneuron. Inhibits transmission of monosynaptic and polysynaptic reflexes at the spinal cord level by hyperpolarization and induces resultant relief of muscle spasticity.
PK: Onset 1 hour. t1/2: 3-4 hours. Duration: 4-8 hours.
Pregnancy: C
Indications: REFRACTORY GERD that has failed antacid treatment
GABA-B Agonist - Baclofen (ADRs and Considerations)
ADRs: sedation, muscle relaxation
Considerations: Used in refractory GERD- patients with lack of response when adhering to twice daily PPI even after dose adjustment and alignments with meals (10-40% of patients). Dose adjustment needed for pts with renal disease. Not to be confused with Bactroban.
Gastric Ulcer vs. Duodenal Ulcer
Gastric ulcer:
- Pain occurs any time during day
- Food precipitates pain or worsens pain
- Causes weight loss, nausea, vomiting, and diffuse gastric pain
Duodenal ulcer:
- Pain occurs at night and will cause awakenings from sleep
- Pain occurs 1-3 hours after a meal (empty stomach)
- Pain is relieved by food
- Causes weight gain and pinpoint epigastric burning pain
Cytoprotectant Agents (Classes and Agents; 2 and 3)
Prostaglandin analog:
- Misoprostol
Surface protectant:
- Sucralfate
- Colloidal bismuth
How do NSAIDs damage the mucosal barrier?
NSAIDs decrease prostaglandin synthesis (E2 and I2), which decreases gastric mucus secretion, bicarbonate secretion, and blood flow (healing)