Drug Name
Generic Name : cimetidine
Brand Name: Apo-Cimetidine (CAN), Gen-Cimetidine (CAN), Novo-Cimetine (CAN), Nu-Cimet (CAN), Tagamet, Tagamet HB, Tagamet HB Suspension
Classification: Histamine2 (H2) antagonist
Pregnancy Category B
Dosage & Route
Adults
- Active duodenal ulcer: 800 mg PO hs or 300 mg PO qid with meals and at bedtime or 400 mg PO bid; continue for 4–6 wk unless healing is demonstrated by endoscopy. For intractable ulcers, 300 mg IM or IV q 6–8 hr.
- Maintenance therapy for duodenal ulcer: 400 mg PO at bedtime.
- Active benign gastric ulcer: 300 mg PO qid with meals and at bedtime or 800 mg at bedtime.
- Pathologic hypersecretory syndrome: 300 mg PO qid with meals and at bedtime, or 300 mg IV or IM q 6 hr. Individualize doses as needed; do not exceed 2,400 mg/day.
- Erosive GERD: 1,600 mg PO in divided doses bid–qid for 12 wk.
- Prevention of upper GI bleeding: Continuous IV infusion of 50 mg/hr. Do not treat beyond 7 days.
- Heartburn, acid indigestion: 200 mg as symptoms occur; up to 4 tablets/24 hr. Do not take maximum dose for > 2 wk.
Pediatric Patients
- Not recommended for children < 12 yr.
Geriatric Patients or Patients with Impaired Renal Function
- Accumulation may occur. Use lowest dose possible, 300 mg PO or IV q 12 hr; may be increased to q 8 hr if patient tolerates it and levels are monitored; if creatinine clearance < 30 mL/min, give 25 mg/hr IV for prevention of upper GI bleed.
Therapeutic actions
- Cimetidine competitively inhibits histamine at H2-receptors of the gastric parietal cells resulting in decreased gastric acid secretion, gastric volume and hydrogen ion concentration. It is a potent inhibitor of metabolism in the hepatic mixed-function oxidase systems. It is also used in patients with pancreatic insufficiency to reduce the breakdown of pancreatic enzyme supplements.
Indications
- Short-term treatment and maintenance of active duodenal ulcer
- Short-term treatment of benign gastric ulcer
- Treatment of pathologic hypersecretory conditions (Zollinger-Ellison syndrome)
- Prophylaxis of stress-induced ulcers and acute upper GI bleeding in critical patients
- Treatment of erosive GERD
- OTC use: Relief of symptoms of heartburn, acid indigestion, sour stomach
Adverse effects
- Diarrhea, dizziness, tiredness, rash, headache, CNS disturbances, arthralgia, myalgia, gynecomastia, alopecia, blood dyscrasias, nephritis, hepatitis, pancreatitis, granulocytopenia, hypersensitivity reactions.
Contraindications
- Hypersensitivity, lactation.
Nursing considerations
Assessment
- History: Allergy to cimetidine, impaired renal or hepatic function, lactation
- Physical: Skin lesions; orientation, affect; pulse, baseline ECG (continuous with IV use); liver evaluation, abdominal examination, normal output; CBC, LFTs, renal function tests
Interventions
- Give drug with meals and at bedtime.
- Decrease doses in renal and hepatic impairment.
- Administer IM dose undiluted deep into large muscle group.
- Arrange for regular follow-up, including blood tests to evaluate effects.
Teaching points
- Take drug with meals and at bedtime; therapy may continue for 4–6 weeks or longer.
- Take antacids as prescribed and at recommended times.
- Inform your health care provider about your cigarette smoking habits. Cigarette smoking decreases the drug’s effectiveness.
- Have regular medical follow-up care to evaluate your response to drug.
- Tell your health care providers about all medications, over-the-counter drugs, or herbs you take; this drug may interact with many of these.
- Report sore throat, fever, unusual bruising or bleeding, tarry stools, confusion, hallucinations, dizziness, muscle or joint pain.