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cimetidine (sye-met-i-deen)

imageApo-Cimetidine, imageNovocimetine, imagePeptol, Tagamet, Tagamet HB


Therapeutic: antiulcer agents

Pharmacologic: histamine H2 antagonists


Short-term treatment of active duodenal ulcers and benign gastric ulcers. Maintenance therapy for duodenal ulcers after healing of active ulcer(s). Management of gastroesophageal reflux disease (GERD). Treatment of heartburn, acid indigestion, and sour stomach (OTC use). Management of gastric hypersecretory states (Zollinger-Ellison syndrome). IV: Prevention and treatment of stress-induced upper GI bleeding in critically ill patients. Unlabeled Use: Management of GI symptoms associated with the use of NSAIDs. Prevention of stress ulceration or aspiration pneumonitis. Prevention of acid inactivation of supplemental pancreatic enzymes in patients with pancreatic insufficiency. Management of urticaria.


Inhibits the action of histamine at the H2 receptor site located primarily in gastric parietal cells, resulting in inhibition of gastric acid secretion. Therapeutic Effects: Healing and prevention of ulcers. Decreased symptoms of gastroesophageal reflux. Decreased secretion of gastric acid.

Adverse Reactions/Side Effects

CNS: confusion, dizziness, drowsiness, hallucinations, headache. CV: ARRHYTHMIAS. GI: constipation, diarrhea, drug-induced hepatitis, nausea. GU: decreased sperm count, erectile dysfunction. Endo: gynecomastia. Hemat: AGRANULOCYTOSIS, APLASTIC ANEMIA, anemia, neutropenia, thrombocytopenia. Local: pain at IM site. Misc: hypersensitivity reactions.


Examination and Evaluation

  • Assess heart rate, ECG, and heart sounds, especially during exercise (See Appendices G, H). Report any rhythm disturbances or symptoms of increased arrhythmias, including palpitations, chest discomfort, shortness of breath, fainting, and fatigue/weakness.

  • Report signs of agranulocytosis and neutropenia (fever, sore throat, mucosal lesions, signs of infection, bruising), aplastic anemia (unusual fatigue, weakness), or thrombocytopenia (bruising, bleeding gums, nose bleeds).

  • Monitor signs of hypersensitivity reactions, including pulmonary symptoms (tightness in the throat or chest, wheezing, cough, dyspnea) or skin reactions (rash, pruritus, urticaria). Notify physician or nursing staff immediately if these reactions occur.

  • Assess dizziness and drowsiness that might affect gait, balance, and other functional activities (see Appendix C). Report balance problems and functional limitations to the physician and nursing staff, and caution the patient and family/caregivers to guard against falls and trauma.

  • Monitor other CNS symptoms such as confusion, hallucinations, and headache. Excessive or prolonged CNS symptoms may require a reduction in dose.

  • If treating allergic skin reactions (urticaria), assess degree of itching, skin rash, and inflammation to help determine effects of drug therapy.

  • Monitor IM injection site for pain, swelling, and irritation. Report prolonged or excessive injectionsite reactions to the physician.


  • Use caution during aerobic exercise and endurance conditioning because of an increased risk of cardiac arrhythmias. Terminate exercise if patient exhibits untoward symptoms (chest pain, shortness of breath, etc.) or displays other criteria for exercise termination (See Appendix L).

Patient/Client-Related Instruction


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