• Hyperacidity, GERD, and ulcers

Cimetidine Generic Name & Formulations

General Description

Cimetidine 200mg, 300mg, 400mg, 800mg; tabs.

Pharmacological Class

H2 blocker.

How Supplied

Contact supplier

Cimetidine Indications


Active duodenal or benign gastric ulcer. Maintenance of healed duodenal ulcers. Pathological hypersecretory conditions (eg, Zollinger-Ellison syndrome). GERD.

Cimetidine Dosage and Administration


Active duodenal ulcer: 800mg at bedtime for 4–8 weeks. Maintenance: 400mg at bedtime. Active benign gastric ulcer: 800mg at bedtime or 300mg 4 times daily with meals and at bedtime for 6 weeks. Hypersecretory conditions: 300mg 4 times daily with meals and at bedtime; max 2.4g/day. GERD: 800mg 2 times daily or 400mg 4 times daily for max 12 weeks; see full labeling. For difficult to heal ulcers: see full labeling.


<16yrs: not recommended; see full labeling. Doses of 20–40mg/kg per day have been used.

Cimetidine Contraindications

Not Applicable

Cimetidine Boxed Warnings

Not Applicable

Cimetidine Warnings/Precautions


Impaired renal or hepatic function. Elderly. Debilitated. Immunocompromised. Pregnancy (Cat.B). Nursing mothers: not recommended.

Cimetidine Pharmacokinetics

See Literature

Cimetidine Interactions


Avoid antacids within 1 hour of dosing. May potentiate anticoagulants, phenytoin, theophylline, lidocaine, and others (see literature) by inhibition of hepatic microsomal enzymes. May alter absorption of drugs affected by gastric pH (e.g., ketoconazole), give 2 hours before cimetidine.

Cimetidine Adverse Reactions

Adverse Reactions

Headache, diarrhea, dizziness, somnolence, CNS disturbances, gynecomastia, rash (maybe serious eg, Stevens-Johnson syndrome); rare: arthralgia, myalgia, blood dyscrasias, nephritis, increased serum transaminases, pancreatitis, bradycardia, tachycardia; increased risk of community-acquired pneumonia (see literature).

Cimetidine Clinical Trials

See Literature

Cimetidine Note


Formerly known under the brand name Tagamet.

Cimetidine Patient Counseling

See Literature