OB-GYN 101
Pharmacy

Category:

• Gastrointestinal

Description:

• Antiulcer agent (H2 antagonist)

Indications:

• Short term and maintenance duodenal ulcer therapy

• Short term benign gastric ulcer therapy

• Pathological hypersecretory conditions (Zollinger-Ellison syndrome)

• Gastroesophageal disease (GERD) and esophagitis due to GERD

Drug Interactions:

• Reduction of gastric acidity reduces absorption and introduces potential for therapeutic failure: ketoconazole, enoxacin, cefpodoxime, cefuroxime

• Increased absorption, potential for hypoglycemia: glipizide, glyburide

• Increased concentrations: nifedipine, nisoldipine

Precautions:

• Pregnancy category B; concentrated in breast milk (but less than cimetadine or ranitadine, but considered compatible with breast feeding)

• Symptomatic response does not rule out gastric malignancy

Adverse Reactions (Side Effects):

• CNS: anxiety, depression, dizziness, fever, headache, insomnia, paresthesia, seizures, somnolence

• EENT: Orbital edema, taste change, tinnitis

• HEME: Thrombocytopenia

• RESP: Bronchospasm

• Arthralgia, myalgia, rash

Available orally (suspension, tablet) and intravenously

• Adult Dose:

  • Duodenal ulcer: 

    • 40mg orally every night at bedtime for 4-8 weeks, then 20mg thereafter if needed for maintenance.  

    • IV; 20mg every 12 hours if unable to tolerate PO

  • Gastric Ulcer: 

    • 40mg orally every night at bedtime

  • GERD: 

    • PO 20mg twice daily for up to 6 weeks; for esophagitis due to GERD, 20-40mg twice daily for up to 12 weeks

  • Hypersecretory conditions: 

    • PO 20mg every 6 hours; may give 160mg every 6 hours if needed.  

    • IV 20mg every 12 hours if unable to tolerate PO

  • Heartburn or acid indigestion: 

    • PO 10mg twice daily; to prevent heartburn, 10mg 1 hour before meals

  • Renal failure: 

    • PO 20mg at bedtime or increase dosing interval to 36-48 hours