Action

Inhibits histamine action at H₂-receptor sites in gastric parietal cells, reducing gastric acid secretion and pepsin production

Availability

Capsules: 150 mg, 300 mg

Oral solution: 15 mg/ml

Tablets: 75 mg

Indications and dosages

➣ Active duodenal ulcer Adults: 300 mg P.O. daily at bedtime or 150 mg b.i.d. for up to 8 weeks

➣ Maintenance of healed duodenal ulcers

Adults and children ages 12 and older: 150 mg P.O. daily at bedtime for up to 1 year

➣ Esophagitis and associated heartburn caused by gastroesophageal reflux disease (GERD)

Adults: 150 mg P.O. b.i.d. for up to 12 weeks

➣ Active benign gastric ulcer Adults: 150 mg P.O. b.i.d. or 300 mg P.O. once daily at bedtime

➣ Erosive esophagitis; GERD

Children ages 12 and older: 150 mg P.O. b.i.d. for up to 8 weeks

Dosage adjustment

• Moderate to severe renal impairment

• Elderly patients

Contraindications

• Hypersensitivity to drug or other H₂-receptor antagonists

Precautions

Use cautiously in:

• mild renal impairment

• elderly patients

• pregnant or breastfeeding patients

• children younger than age 12 (safety and efficacy not established).

Administration

• Give with or without food.

• If patient is to take drug twice daily, give one dose in morning and one at bedtime.

Adverse reactions

CNS: dizziness, drowsiness, headache, anxiety, nervousness, insomnia, abnormal dreams, asthenia

CV: chest pain

EENT: amblyopia, sinusitis, rhinitis, pharyngitis

GI: nausea, vomiting, diarrhea, constipation, dyspepsia, abdominal pain, flatulence, anorexia, dry mouth

Hematologic: anemia

Musculoskeletal: back pain, myalgia

Respiratory: cough

Skin: rash, pruritus

Other: tooth disorder, infection, fever, pain

Interactions

Drug-drug. Salicylates (high doses): increased salicylate blood level

Drug-diagnostic tests. Alanine amino-transferase, alkaline phosphatase, aspartate aminotransferase: elevated levels

Urobilinogen tests using Multistix: false-positive result

Drug-herbs. Pennyroyal: altered rate of herbal metabolite formation

Patient monitoring

• Monitor liver and renal function tests.

• Check temperature; watch for fever and other signs and symptoms of infection.

Patient teaching

• Advise patient to take once-daily dose at bedtime with or without food, or twice-daily doses in morning and at bedtime.

• Instruct patient to take exactly as prescribed. Caution him not to take other OTC drugs (especially aspirin).

• Tell patient to report signs and symptoms of infection.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.

• As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs, tests, and herbs mentioned above.