Cimetidine Tablets

Category: H2 receptor antagonist
Form: Oral tablets

Uses:

• Treatment of peptic ulcers (gastric and duodenal ulcers).

• Management of gastroesophageal reflux disease (GERD) and heartburn.

• Treatment of Zollinger-Ellison syndrome (a condition causing excess stomach acid).

• Sometimes used to relieve acid-related dyspepsia.

Mechanism of Action:

• Cimetidine blocks histamine H2 receptors on the stomach lining.

• This reduces gastric acid secretion, decreasing acidity in the stomach.

• Helps promote healing of ulcers and reduce symptoms like pain and heartburn.

Administration:

• Taken orally, usually 1–4 times daily, depending on the condition and severity.

• Can be taken with or without food, though some prefer taking it after meals and at bedtime to reduce nighttime acid secretion.

• Duration of therapy depends on the condition (ulcers may require 4–8 weeks of treatment).

Side Effects:

• Common: headache, dizziness, diarrhea, constipation, fatigue.

• Other: mild rash, muscle pain, confusion (especially in elderly patients).

• Rare but serious:

  • Liver enzyme abnormalities

  • Blood disorders (rare)

  • Drug interactions due to inhibition of liver enzymes (CYP450)

Precautions:

• Use cautiously in elderly patients and those with liver or kidney impairment.

• Can interact with many drugs (e.g., warfarin, phenytoin, theophylline) because it affects liver metabolism.

• Avoid long-term use without medical supervision.

• Monitor for signs of gastrointestinal bleeding or worsening symptoms.

Summary:
Cimetidine Tablets are an H2 receptor antagonist used to reduce stomach acid in conditions like peptic ulcers, GERD, and Zollinger-Ellison syndrome. They work by blocking histamine receptors in the stomach, decreasing acid production. Common side effects include headache, dizziness, and gastrointestinal disturbances, while rare but serious effects include liver enzyme changes, blood disorders, and drug interactions, particularly with medications metabolized by the liver.