H2 receptor antagonist (H2 blockers)

Prototype: famotidine

Prototype: famotidine

Action: block H2 receptors- suppresses gastric acid production/secretion

Contraindications:

• children/elderly- elderly can experience cns effects, adjust doses
• kidney impairment- need adjusted doses
• respiratory disease- use cautiously in pts at risk for PNA (eg COPD)- raises ph of stomach, creating breeding ground for bacteria in stomach + resp tract
• preg women
• tobacco smokers

Side/adverse effects:

• CNS effects (esp elderly)- headaches dizziness lethargy, hallucinations, confusion, restlessness
• sexual dysfunction in men (blocks androgen receptors)- impotence, low libido, gynecomastia, erectile dysfunction
• GI upset- constipation, diarrhea nausea
• blood dyscrasias- leukocytopenia, thrombocytopenia

Considerations/pt teaching:

• can ↑ warfarin levels-> monitor for bleeding, PT/INR levels
• NO SMOKING- can ↓ effectiveness of H2 blockers
• ADMIN H2 BLOCKER RIGHT BEFORE MEAL
• DONT take antacids w the med- take antacid 1 hr before or after the H2 blocker

Antacids

Prototype: Aluminum hydroxide

Prototype: Aluminum hydroxide

Others: sodium bicarbonate, magnesium hydroxide

Action: neutralize HCl + reduce pepsin activity if pH >5; does not coat the ulcer (only adsorbents [Bismuth] + sucralfate does)

Contraindications:

• elderly/children
• pregnancy,
• hepatic/renal disease
• diarrhea/dehydration,
• GI bleeding/perforation or obstruction,
• hypophosphatemia (Al used to reduce PO4 levels)

Side/adverse effects:

• electrolyte imbalances
• Aluminum hydroxide:
  • hypophosphatemia (used to reduce phosphate levels), constipation if used LT
  • anorexia, weakness, impaired cognition
• Magnesium hydroxide:
  • hypermagnesemia if kidney impairment, diarrhea if used LT
• Sodium bicarbonate: HTN, water retention - not for HF or HTN
• Drug interactions: Al compounds decrease effect of warfarin digoxin and tetracycline

Considerations/pt teaching:

• DO NOT GIVE IF PT HAS GI BLEEDING- UC/Crohns, inflammatory bowel conditions
• Pt teaching:
  • Take antacid 1-3 hrs after meals
    • liquid form- take w very little water
    • tablet form- chew + follow w 8 oz of water/milk
  • Take all other meds 1 hr after an antacid
  • Don't take antacids with H2 blockers (↓ their effectiveness)- take antacid 1 hr before H2 blocker
  • Al compounds ↓ effectiveness of digoxin, warfarin + tetracyclines – take at least an hr between meds

Pepsin inhibitors (mucosal protectants)

Prototype: sucralfate (sucrose + aluminum) 

Prototype: sucralfate (sucrose + aluminum)

Action: combines w protein to form a thick gel/paste and cover ulcer from acid + pepsin; does not neutralize acid or decrease acid production

Contraindications: diabetes mellitus, renal impairment, dysphagia, pregnancy/breastfeeding, older adults

Side effects:

• GI effects- constipation, n/v, flatulence
• hyperglycemia, hypophosphatemia 
• dry mouth, rash/pruritis, angioedema
• headache, drowsiness/dizziness

Pt teaching:

• take on an empty stomach, 4x per day- 30 mins before meals + at bedtime for 4-6 wks
• DONT TAKE W ANTACIDS (↓ effects of sucralfate) - take 30 mins before or after antacid
• fluids, fiber + exercise to relieve constipation
• NO SMOKING + avoid irritating liquids/foods

Proton Pump Inhibitors (PPIs)- ("-prazole")

Prototype: Pantoprazole

Prototype: Pantoprazole

Action: reduce gastric acid secretion by inhibiting H+/K+ ATPase enzyme in gastric parietal cells- block final step of acid production

Contraindications:

• elderly, bone fractures/osteoporosis, hepatic impairment, pregnancy/breastfeeding, diarrhea

Side effects:

• PNA- observe for s/s, report to PCP if they occur
• B12 deficiency, hypoMg- monitor labs + admin supplements if needed
• C. diff infx- report fever, diarrhea, bloody stool, abd cramping
• GI issues- abd pain, diarrhea, or constipation, n/v, flatulence
• Bone/blood issues- osteoporosis/bone fractures w LT use, joint pain, muscle pain, weakness; 
• Blood disorders- leukocytopenia, thrombocytopenia
• Risk of cancer w prolonged use
• CNS effects/depression- headache, dizziness/drowsiness, depression, blurred vision, edema

Pt teaching- Take before meals, do not crush chew or break the med

Prostaglandin E analogs (misoprostol)

Action: suppresses gastric acid secretion, causes moderate decrease in pepsin secretion, increases cytoprotective mucus in GI tract

Recommended for pts on long term NSAID therapy

Contraindications:

• pregnancy/childbearing age- induces labor

Side effects:

• diarrhea, abd pain, flatulence
• dysmenorrhea/spotting- notify PCP if occurs
• chills/shivering
• hyperthermia

Considerations:

• pt teaching- take w meals + at bedtime
• Pt who may become pregnant:
  • must be warned verbally and written about misoprostol,
  • have negative blood pregnancy test 2 weeks before starting therapy,
  • be able to adhere to contraceptives,
  • and start the med on 2nd or 3rd day of menstrual cycle