cimetidine (redirected from Tagamet HB)

cimetidine /ci·met·i·dine/ (si-met´i-den) a histamine H2 receptor antagonist, which inhibits gastric acid secretion; used as the base or the monohydrochloride salt in the treatment and prophylaxis of gastric or duodenal ulcers, gastroesophageal reflux disease, upper gastrointestinal bleeding, and conditions associated with gastric hypersecretion.

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ci·met·i·dine (s-mt-dn, -dn)

n.

A histamine antagonist used to treat peptic ulcer and hypersecretory conditions by inhibiting gastric acid secretion.

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cimetidine (simet´idēn´),

n brand names: Tagamet, Apo-Cimetidine;
drug class: H₂-histamine receptor antagonist;
action: inhibits histamine at H₂-histamine receptor site in parietal cells, which inhibits gastric acid secretion;
uses: short-term treatment of duodenal and gastric ulcers by the control of hyperacidity.

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cimetidine

a histamine H₂-receptor antagonist that inhibits the action of histamine at cell surface receptors of the gastric parietal cells and reduces basal gastric acid secretion and secretion stimulated by food, histamine, gastrin and insulin. It is used for short-term treatment of peptic ulcer and for treatment of pathological hypersecretory conditions.

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cimetidine

Apo-Cimetidine (CA), Dyspamet (UK), Galenmet (UK), Novo-Cimetine (CA), Nu-Cimet (CA), Tagamet HB

Pharmacologic class: Histamine₂-receptor antagonist

Therapeutic class: Antiulcer drug

Pregnancy risk category B

Action

Competitively inhibits histamine action at histamine₂-receptor sites of gastric parietal cells, thereby inhibiting gastric acid secretion

Availability

Oral liquid: 200 mg/5 ml, 300 mg/5 ml

Solution for injection: 300 mg/2-ml vials, 300 mg/50 ml premixed in normal saline solution

Tablets: 100 mg, 200 mg, 300 mg, 400 mg, 600 mg, 800 mg

⊘Indications and dosages

➣ Active duodenal ulcer (short-term therapy)

Adults and children older than age 16: 800 mg P.O. at bedtime, or 300 mg P.O. q.i.d. with meals and at bedtime, or 400 mg P.O. b.i.d. Maintenance dosage is 400 mg P.O. at bedtime.

➣ Active benign gastric ulcer (short-term therapy)

Adults and children older than age 16: 800 mg P.O. at bedtime or 300 mg P.O. q.i.d. with meals and at bedtime

➣ Gastric hypersecretory conditions (such as Zollinger-Ellison syndrome); intractable ulcers

Adults and children older than age 16: 300 mg P.O. q.i.d. with meals and at bedtime; in hospitalized patients, 300 mg I.M. or I.V. q 6 hours

➣ Erosive gastroesophageal reflux disease

Adults and children older than age 16: 1,600 mg P.O. daily in divided doses (800 mg b.i.d. or 400 mg q.i.d.) for 12 weeks

➣ Prevention of stress-induced upper GI bleeding in critically ill patients

Adults and children older than age 16: 50 mg/hour as a continuous I.V. infusion

➣ Heartburn; acid indigestion

Adults and children older than age 16: 200 mg (two tablets of over-the-counter product only) P.O. up to b.i.d. Give maximum dosage no longer than 2 weeks continuously, unless directed by prescriber.

Dosage adjustment

• Renal impairment

Off-label uses

• Acetaminophen overdose
• Adjunctive therapy in burns
• Barrett's esophagus
• Renal cancer
• Anaphylaxis

Contraindications

• Hypersensitivity to drug
• Alcohol intolerance (oral drug forms)

Precautions

Use cautiously in:
• renal impairment
• elderly patients
• pregnant or breastfeeding patients.

Administration

• Give P.O. doses with meals.
• Give I.M. doses undiluted.
• Dilute I.V. doses in normal saline solution or other compatible solution.
• Administer I.V. injection over at least 5 minutes; may give intermittent infusion over 15 to 20 minutes.
• Give continuous I.V. infusion at a rate of 37.5 mg/hour over 24 hours, using an infusion pump.
• When giving drug to prevent stress ulcers, administer by continuous I.V. infusion at a rate of 50 mg/hour.

Route	Onset	Peak	Duration
P.O.	30 min	45-90 min	4-5 hr
I.V., I.M.	10 min	30 min	4-5 hr

Adverse reactions

CNS: confusion, dizziness, drowsiness, hallucinations, agitation, psychosis, depression, anxiety, headache

GI: diarrhea

GU: reversible erectile dysfunction, gynecomastia

Other: pain at I.M. injection site

Interactions

Drug-drug. Calcium channel blockers, carbamazepine, chloroquine, lidocaine, metformin, metronidazole, moricizine, pentoxifylline, phenytoin, propafenone, quinidine, quinine, some benzodiazepines, some beta-adrenergic blockers (chlordiazepoxide, diazepam, midazolam), sulfonylureas, tacrine, theophylline, triamterene, tricyclic antidepressants, valproic acid, warfarin: decreased metabolism of these drugs, possible toxicity

Drug-diagnostic tests. Creatinine, transaminases: increased levels

Parathyroid hormone: decreased level

Prolactin (after I.V. bolus of cimetidine): increased level

Skin tests using allergenic extracts: false-negative results (drug should be discontinued 24 hours before testing)

Drug-food. Caffeine-containing foods and beverages (such as coffee, chocolate): increased cimetidine blood level, increased risk of toxicity

Drug-herbs. Pennyroyal: change in formation rate of herb's toxic metabolite

Yerba maté: decreased yerba maté clearance, possible toxicity

Drug-behaviors . Alcohol use: increased blood alcohol level

Smoking: reversed cimetidine effects

Patient monitoring

• Monitor creatinine levels in patients with renal insufficiency or failure.
• Assess elderly or chronically ill patients for confusion (which usually resolves once drug therapy ends).

Patient teaching

• Inform patient with gastric ulcer that ulcer may take up to 2 months to heal. Advise him not to discontinue therapy, even if he feels better, without first consulting prescriber. Ulcer may recur if therapy ends too soon.
• Advise patient not to take over-the-counter cimetidine for more than 2 weeks continuously, except with prescriber's advice and supervision.
• As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs, tests, foods, herbs, and behaviors mentioned above.

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cimetidine Tagamet^™ Clinical therapeutics An H₂-receptor antagonist used to treat peptic ulcer disease Adverse reactions Diarrhea, headache, drowsiness, fatigue, muscle pain, constipation; rarely mental confusion, agranulocytosis, gynecomastia, impotence, allergic reactions, myalgias, tachycardia, arrhythmias, interstitial nephritis, mild ↑ in creatinine. See Histamine receptor antagonists.