Nizatidine

Indications

Nizatidine is indicated for up to 8 weeks for the treatment of active duodenal ulcer. In most patients, the ulcer will heal within 4 weeks.

Nizatidine is indicated for maintenance therapy for duodenalulcer patients, at a reduced dosage of 150 mg h.s. after healing of an active duodenal ulcer. The consequences of continuous therapy with Nizatidine for longer than 1 year are not known.

Nizatidine is indicated for up to 12 weeks for the treatment of endoscopically diagnosed esophagitis, including erosive and ulcerative esophagitis, and associated heartburn due to GERD.

Nizatidine is indicated for up to 8 weeks for the treatment of active benign gastric ulcer. Before initiating therapy, care should be taken to exclude the possibility of malignant gastric ulceration.

Pharmacology

Nizatidine is a competitive, reversible inhibitor of histamine at the histamine H2-receptors, particularly those in the gastric parietal cells. By inhibiting the action of histamine on stomach cells, nizatidine reduces stomach acid production. Nizatidine had no demonstrable antiandrogenic action. Full-dose therapy for the problems treated by nizatidine lasts no longer than 8 weeks. It has been demonstrated that treatment with a reduced dose of nizatidine is effective as maintenance therapy following healing of active duodenal ulcers.

Dosage And Administration

Active Duodenal Ulcer: The recommended oral dosage for adults is 300 mg once daily at bedtime. An alternative dosage regimen is 150 mg twice daily.

Maintenance of Healed Duodenal Ulcer: The recommended oral dosage for adults is 150 mg once daily at bedtime.

Gastroesophageal Reflux Disease: The recommended oral dosage in adults for the treatment of erosions, ulcerations, and associated heartburn is 150mg twice daily.

Active Benign Gastric Ulcer: The recommended oral dosage is 300 mg given either as 150 mg twice daily or 300 mg once daily at bedtime. Prior to treatment, care should be taken to exclude the possibility of malignant gastric ulceration.

Interaction

No interactions have been observed between Nizatidine and theophylline, chlordiazepoxide, lorazepam, lidocaine, phenytoin, and warfarin. Nizatidine does not inhibit the cytochrome P-450-linked drug-metabolizing enzyme system; therefore, drug interactions mediated by inhibition of hepatic metabolism are not expected to occur. In patients given very high doses (3,900 mg) of aspirin daily, increases in serum salicylate levels were seen when nizatidine, 150 mg b.i.d., was administered concurrently.

Contraindications

Nizatidine is contraindicated in patients with known hypersensitivity to the drug. Because cross sensitivity in this class of compounds has been observed, H2-receptor antagonists, including Nizatidine , should not be administered to patients with a history of hypersensitivity to other H2-receptor antagonists.

Side Effects

Headache, dizziness, insomnia, abnormal dreams, somnolence, asthenia, anxiety, excessive sweating, diarrhoea, nausea and/or vomiting, abdominal pain/discomfort, constipation, flatulence, dyspepsia, dry mouth, anorexia, tooth disorder, urticaria, rash, pruritus, exfoliative dermatitis, anaemia, rhinitis, pharyngitis, sinusitis, reversible hepatocellular injury, diaphoresis, myalgia, fever. Rarely, asymptomatic ventricular tachycardia, thrombocytopenic purpura, decreased libido, gynaecomastia, reversible cholestatic or mixed cholestatic-hepatocellular injury with jaundice.

Pregnancy And Lactation

Pregnancy Category B. Either animal-reproduction studies have not demonstrated a foetal risk but there are no controlled studies in pregnant women or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the 1st trimester (and there is no evidence of a risk in later trimesters).

Precautions And Warnings

Possibility of malignancy should be excluded prior to therapy as the drug may mask symptoms and delay diagnosis of gastric malignancy. Increased risk of community-acquired pneumonia. Renal impairment. Pregnancy and lactation.

Overdose Effects

Symptoms: Lacrimation, salivation, emesis, miosis, and diarrhoea.

Management: Symptomatic and supportive treatment. Activated charcoal, emesis or lavage may reduce absorption.

Therapeutic Class

H2 receptor antagonist.

Use in special populations

Dosage Adjustment for Patients With Moderate to Severe Renal Insufficiency-

Active Duodenal Ulcer, GERD and Benign Gastric Ulcer:

  • CrCl 20-50 ml/min: 150 mg daily
  • CrCl <20 ml/min: 150 mg every other day

Maintenance Therapy:

  • CrCl 20-50 ml/min: 150 mg every other day
  • CrCl <20 mL/min: 150 mg every 3 days

Some elderly patients may have creatinine clearances of less than 50 ml/min, and, based on pharmacokinetic data in patients with renal impairment, the dose for such patients should be reduced accordingly. The clinical effects of this dosage reduction in patients with renal failure have not been evaluated.

Storage Conditions

Store at 25°C.

Available Brand Names