Ranitadine (Zantac)


  • Gastrointestinal


  • Antiulcer agent (H2 antagonist)


  • Duodenal ulcer; benign gastric ulcer

  • Pathological hypersecretory conditions (Zollinger-Ellison syndrome)

  • Gastroesophageal reflux disease (GERD)

  • Erosive gastritis

  • Stress ulcer prophylaxis

Drug Interactions:

  • Reduced efficacy: cefuroxine, cefpodoxime

  • Enhanced hypoglycemic effect: glipizide

  • Increased bioavailability: nifedipine, nitrendipine, nisoldipine

  • Decreased plasma concentrations: ketoconazole, enoxacin


  • Pregnancy category B; compatible with breast feeding

  • Stagger doses of ranitadine and antacids

Adverse Reactions (Side Effects):

  • CNS: dizziness, insomnia, malaise, somnolence, vertigo

  • CV: atrioventricular block, bradycardia, premature ventricular beats, tachycardia

  • GI: Abdominal discomfort or pain, constipation, hepatitis, increased liver function tests, nausea, vomiting, pancreatitis (rare)

  • HEME: granulocytopenia, leukopenia, thrombocytopenia

  • SKIN: alopecia, erythema multiforme (rare), rash

  • MS: arthralgias, myalgias


Administered PO (tablets, gelatin capsules, syrup), IV, and IM

  • Adult: 

    • Duodenal and gastric ulcer: PO 150mg twice daily or 300mg at bedtime for 4-8 weeks, maintenance 150mg every night at bedtime

    • GERD: 

      • PO 150mg twice daily

    • Erosive esophagitis: 

      • PO 150mg four times daily, maintenance 150mg twice daily

    • Pathological hypersecretory conditions: 

      • PO 150mg twice daily initially, titrate to desired response up to 6 grams daily

      • IV INF start 1mg/kg/hr, increase by 0.5mg/kg/hr intervals every 4 hours as needed up to 2.5mg/kg/hr

      • IM/IV 50mg every 6 to 8 hours, do not exceed 400mg per day; 

      • IV INF 6.25mg/hr

  • Child:

    • PO 1.25mg/kg every 12 hours, max 300mg/kg/day

    • IM/IV 0.75-1.5mg/kg every 6-8 hours, max 6mg/kg/day or 300mg/day

    • IV INF 0.1-0.25mg/kg/hr

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