Trade Names:Cimetidine- Tablets 300 mg- Tablets 400 mg- Tablets 800 mg- Liquid 300 mg (as hydrochloride) per 5 mL- Injection 150 mg (as hydrochloride) per mL
Trade Names:Cimetidine in 0.9% Sodium Chloride- Injection, premixed 6 mg (as hydrochloride) per mL
Trade Names:Tagamet HB- Tablets 200 mgApo-Cimetidine (Canada)Gen-Cimetidine (Canada)Nu-Cimet (Canada)
Reversibly and competitively blocks histamine at H 2 receptors, particularly those in gastric parietal cells, leading to inhibition of gastric acid secretion.
Rapidly absorbed. T max is 45 to 90 min. 60% to 70% bioavailable.
13% to 25% protein bound. Vd is 0.8 to 1.2 L/kg. Crosses the placenta and is excreted in breast milk.
Following oral administration, cimetidine is extensively metabolized with the sulfoxide being the major metabolite.
The t ½ is about 2 h.Oral
48% is excreted unchanged in the urine.IV/IM
About 75% is excreted unchanged in the urine.
Drug accumulation may occur in those with severe renal failure. Dosage adjustment may be necessary.
Management of duodenal ulcer; treatment of gastroesophageal reflux disease (GERD), including erosive esophagitis; therapy for benign gastric ulcer; treatment of pathologic hypersecretory conditions; prevention of upper GI bleeding.
Prevention of aspiration pneumonia and stress ulcers; herpes virus infection; chronic idiopathic urticaria; anaphylaxis (relieves dermatologic symptoms only); dyspepsia; used before anesthesia to prevent aspiration pneumonitis; treatment of hyperparathyroidism and control of secondary hyperparathyroidism in chronic hemodialysis patient; treatment of chronic viral warts in children.
Hypersensitivity to cimetidine or other H 2 antagonists.
PO 800 mg at bedtime for 4 to 6 wk.Alternate regimens
PO 300 mg 4 times daily with meals and at bedtime or 400 mg twice daily.Maintenance Therapy
PO 400 mg at bedtime.Active Benign Gastric UlcerAdults
PO 800 mg at bedtime.GERDAdults
PO 1600 mg daily in divided doses (800 mg or 400 mg) for 12 wk, although some patients may require chronic therapy.Pathologic Hypersecretory ConditionsAdults
PO 300 mg 4 times daily w/meals and at bedtime. If needed, 300 mg doses may be given more often (max, 2400 mg/day).Prevention of Upper GI BleedingAdults
Continuous IV infusion of 50 mg/h. For hospitalized patients with pathologic hypersecretory conditions or intractable ulcers, or patients unable to take PO medication.Usual dose
IM/IV 300 mg every 6 h to 8 h (max 2400 mg/day).
Store premixed products at room temperature. Discard any unused mixed solutions after 48 h. Store oral doseform between 15° to 30°C (59° to 86°F).
May decrease absorption of cimetidine.Benzodiazepines, caffeine, calcium channel blockers, carbamazepine, chloroquine, labetalol, lidocaine, metoprolol, metronidazole, moricizine, pentoxifylline, phenytoin, propranolol, quinidine, quinine, sulfonylureas, theophyllines, triamterene, tricyclic antidepressants, warfarin
Cimetidine may reduce metabolism and increase serum concentration and pharmacologic/toxic effects of these drugs.Carmustine
Bone marrow toxicity may be enhanced.Cigarette smoking
Reversed cimetidine's effects on suppression of nocturnal gastric secretion.Ferrous salts, indomethacin, fluconazole, ketoconazole, tetracyclines
Cimetidine may decrease absorption of these drugs.Hydantoins
Hydantoin levels may increase.Narcotic analgesics
Toxic effects (eg, respiratory depression) may be increased.Procainamide
Levels of procainamide and its active metabolite may increase.Tocainide
Cimetidine may decrease the pharmacologic effects of tocainide.
None well documented.
Headache; somnolence; fatigue; dizziness; confusional states; hallucinations.
Exfoliative dermatitis or erythroderma; alopecia; rash; erythema multiforme; epidermal necrolysis.
Impotence; loss of libido.
Gynecomastia; hypersensitivity reactions; transient pain at injection site; reversible exacerbation of joint symptoms with pre-existing arthritis, including gouty arthritis.
Category B .
Excreted in breast milk.
Safety and efficacy not established.
May have reduced renal function; decreased Cl may occur.
Rare cases of anaphylaxis have occurred as well as rare episodes of hypersensitivity.
Decreased Cl may occur; reduced dosage may be needed.
Use caution; decreased Cl may occur.
Symptomatic relief with cimetidine does not preclude gastric malignancy.
Gynecomastia may occur, especially in patients treated for pathologic hypersecretory states.
Has been followed by rare instances of cardiac arrhythmias and hypotension.
Mental confusion, agitation, psychosis, depression, anxiety, hallucinations, and disorientation have occurred, predominantly in severely ill patients. Advanced age and pre-existing liver or renal disease appear to be contributing factors.
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