Ranitidine

A to Z Drug Facts

 Action Reversibly and competitively blocks histamine at H₂ receptors, particularly those in gastric parietal cells, leading to inhibition of gastric acid secretion.

 Indications Treatment and maintenance of duodenal ulcer; management of gastroesophageal reflux disease (GERD; including erosive or ulcerative disease); short-term treatment of benign gastric ulcer; treatment of pathologic hypersecretory conditions (Zollinger-Ellison). Unlabeled use(s): Prevention of upper GI bleeding; treatment of aspiration pneumonia; stress ulcer; and gastric NSAID damage. Used as a part of a multi-drug regimen to eradicate Helicobacter pylori in the treatment of peptic ulcer; protection against aspiration of acid during anesthesia; prevention of gastro duodenal mucosal damage that may be associated with long-term NSAIDS; to control acute upper GI bleeding; prevention of stress ulcers.

 Contraindications Hypersensitivity to ranitidine or other H₂ antagonists.

 Route/Dosage

Duodenal Ulcer (Active)

ADULTS: PO 150 mg bid or 300 mg at bedtime. Maintenance: 150 mg at bedtime. IM/IV/Intermittent IV 50 mg q 6 to 8 hr.

Acute Benign Gastric Ulcer and GERD

ADULTS: PO 150 mg bid. IM/IV/Intermittent IV 50 mg q 6 to 8 hr.

Pathologic Hypersecretory Conditions

ADULTS: PO 150 mg bid. Individualize.

Erosive Esophagitis

ADULTS: PO 75–150 mg qid. IM/IV/Intermittent IV 50 mg q 6 to 8 hr. Continuous IV 6.25 mg/hr. For patients with Zollinger-Ellison, start infusion at rate of 1 mg/kg/hr and adjust upward in 0.5 mg/kg/hr increments according to gastric acid output (maximum 2.5 mg/kg/hr; infusion rate 220 mg/hr).

Renal Insufficiency (Creatinine Clearance < 50 ml/min)

ADULTS: PO 150 mg q 24 hr. IM/IV 50 mg q 18 to 24 hr.

 Interactions

Diazepam: Pharmacologic effects may be decreased due to decreased GI absorption by ranitidine. Staggering administration times may avoid this reaction. Ethanol: May increase plasma ethanol levels. Glipizide: Possible increased hypoglycemia effect. Ketoconazole: May decrease effects of ketoconazole. Lidocaine: May cause increased lidocaine levels. Warfarin: Ranitidine may interfere with warfarin clearance. Hypoprothrombinemic effects may increase; may need adjustment.

 Lab Test Interferences False-positive test results for urine protein with Multistix may occur during ranitidine therapy; testing with sulfosalicyclic acid is recommended.

 Adverse Reactions

CV: Cardiac arrhythmias; bradycardia. CNS: Headache; somnolence; fatigue; dizziness; hallucinations; depression; insomnia. DERM: Alopecia; rash; erythema multiforme. GI: Nausea; vomiting; abdominal discomfort; diarrhea; constipation; pancreatitis. HEMA: Agranulocytosis; autoimmune hemolytic or aplastic anemia; thrombocytopenia, granulocytopenia. HEPA: Cholestatic or hepatocellular effects. OTHER: Hypersensitivity reactions.

 Precautions

Pregnancy: Category B. Lactation: Excreted in breast milk. Children: Safety and efficacy not established. Elderly patients: May have reduced renal function, therefore decreased drug clearance may be more common. Hepatic impairment: Use drug with caution; decreased clearance may occur. Hepatocellular injury: May occur, manifested as reversible hepatitis, hepatocellular or hepatocanalicular or mixed, with or without jaundice. Hypersensitivity: Rare cases of anaphylaxis have occurred as well as rare episodes of hypersensitivity. Rapid IV administration: May rarely result in bradycardia, tachycardia or premature ventricular beats, usually in patients predisposed to cardiac rhythm disturbances. Renal impairment: Decreased clearance may occur; dosage reduction may be needed. Hemodialysis reduces level of ranitidine-dosage timing must be adjusted so that scheduled dose coincides with end of hemodialysis.

 Administration/Storage

• Intravenous

• For IV use, medication is stable in 5% or 10% Dextrose Injection, 0.9% Sodium Chloride or Lactated Ringer's Solution.
• Administer without regard to meals.
• When administering via IV push, dilute to volume of 20 ml with Saline for Injection and inject over at least 5 min.
• For intermittent infusion, dilute 50 mg in 50 to 100 ml D5W and infuse over 15 to 20 min.
• Do not mix with other IV medications.
• Administer continuous infusion at rate of 6.25 mg/hr except for patients with Zollinger-Ellison syndrome.
• Store diluted IV solutions at room temperature. Discard after 48 hr.

• Oral

• Do not give oral drug at same time as other antacids. Separate administration by at least 1 hr.
• Store syrup form in refrigerator.
• Dissolve EFFERdose tablets in 6 to 8 oz of water.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies.
• Obtain baseline CBC, renal and liver function test results and monitor at regular intervals.
• Assess mental status before starting drug and monitor for changes.
• Notify physician if patient develops right upper quadrant abdominal pain, nausea, vomiting, change in color or consistency of stools, and jaundice.
• Slow rate of IV administration if bradycardia, tachycardia or premature ventricular contractions develop. If these conditions persist, stop infusion and notify physician.
• Notify physician if patient has arrhythmias, headache, fatigue, dizziness, hallucinations, depression, insomnia, alopecia, rash or erythema multiforme, or severe or persistent diarrhea.

 Patient/Family Education

• Instruct patient not to take antacids at same time as drug. Separate administration by at least 1 hr.
• Advise patient to report these symptoms to physician: abdominal pain, nausea, vomiting, change in color or consistency of stools, black stools or coffee ground emesis; jaundice, headache, excessive fatigue, dizziness, unusual bruising or bleeding, petechiae, rash or shortness of breath.
• Discuss necessary dietary changes or restrictions appropriate for patient. Refer patient to dietitian if indicated.
• Advise patient with ulcers to avoid alcohol and smoking.
• Discuss stress reduction with patient if indicated.
• Instruct patient to dissolve effervescent formulation in 6 to 8 oz of water before drinking.
• Advise patient that drug may cause dizziness and to use caution while driving or performing other tasks requiring mental alertness.

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Copyright © 2003 Facts and Comparisons
David S. Tatro
A to Z Drug Facts