Class: Histamine H 2 antagonist
- Injection 10 mg/mL
- Injection, pre-mixed 20 mg/50 mL in 0.9% NaCl
- Tablets 20 mg
- Tablets 40 mg
- Powder for Oral Suspension 40 mg/5 mL when reconstituted
- Tablets, chewable 10 mg
- Tablets 10 mg
- Gelcaps 10 mg
Pepcid AC EZ Chews
- Tablets, chewable 20 mg
Pepcid AC Maximum Strength
- Tablets 20 mg
- Tablets 20 mg
- Tablets 40 mg
Competitively blocks histamine at H 2 receptors, particularly those in gastric parietal cells, leading to inhibition of gastric acid secretion.
Bioavailability is 40% to 45%. T max is 1 to 3 h (PO).
Protein binding is 15% to 20% and Vd is 1.1 to 1.4 L/kg.
The only identified metabolite is S-oxide.
The t 1/ 2 is 2.5 to 3.5 h and 25% to 30% of the oral dose and 65% to 70% of the IV dose is excreted unchanged in the urine.
PO Within 1 h.
IV Within 30 min. PO 1 to 3 h.
IV / PO 10 to 12 h.
Special PopulationsRenal Function Impairment
The t ½ is increased.
Indications and Usage
Short-term treatment of active duodenal ulcer; maintenance therapy for duodenal ulcer patients at reduced dosage after healing of an active ulcer; short-term treatment of active benign gastric ulcer; short-term treatment of gastroesophageal reflux disease (GERD, including erosive or ulcerative disease diagnosed by endoscopy); treatment of pathological hypersecretory conditions. IV is indicated in some hospitalized patients with pathologic hypersecretory conditions, intractable ulcers, or patients unable to take PO.OTC only
Relief and prevention of symptoms of heartburn, acid indigestion, and sour stomach.
Hypersensitivity to other H 2 antagonists.
Dosage and AdministrationDuodenal Ulcer (Active)
PO 40 mg at bedtime or 20 mg twice daily for 4 to 8 wk.Maintenance
20 mg at bedtime.Children (1 to 16 yr of age)
PO 0.5 mg/kg/day at bedtime or divided twice daily (max, 40 mg/day).Benign Gastric Ulcer (Acute)
PO 40 mg at bedtime.GERD
Adults Symptoms of GERD
PO 20 mg twice daily for up to 6 wk.Esophagitis, including erosions and ulcerations
20 or 40 mg twice daily for up to 12 wk.Children (younger than 3 mo of age)
PO 0.5 mg/kg once daily for up to 8 wk.Children (3 mo to younger than 1 yr of age)
PO 0.5 mg/kg twice daily for up to 8 wk.Children (1 to 16 yr of age)
PO 1 mg/kg/day divided twice daily (max, 40 mg twice daily).Pathologic Hypersecretory Conditions
PO Start at 20 mg every 6 h; adjust to individual patient needs and continue as long as clinically indicated; doses up to 160 mg every 6 h have been used.Moderately or Severely Impaired Renal Function (CrCl less than 50 mL/min)
May need to reduce dose 50%, or increase dosing interval to 36 to 46 h.For Hospitalized Patients with Pathologic Hypersecretory Conditions, Intractable Ulcers, or Patients Unable to Take Orally
Parenteral use in GERD not established.Adults and children 16 yr of age and older
IV 20 mg every 12 h.Children (1 to 16 yr of age)
IV 0.25 mg/kg (injected over a period of no less than 2 min or as 15-min infusion) every 12 h (max 40 mg/day).Heartburn, Acid Indigestion, Sour Stomach (OTC only)
Adults and Children 12 yr of age and older Acute
1 tablet 10 to 60 min before eating or drinking.Max
2 tablets/24 h.
- Tablets and suspension are bioequivalent.
- Administer without regard to meals or antacids.
- Prepare suspension at time of dispensing. Add 46 mL purified water.
- Shake suspension vigorously for 5 to 10 sec immediately after adding the water and immediately before measuring dose. Use dosing syringe, dosing spoon, or dosing cup to measure and administer dose.
- For IV administration only.
- Do not add supplementary medication.
- Do not use if discolored, cloudy, or contains particulate matter.
- Check premixed injection container for leaks by firmly squeezing container. Do not use if leaks detected or if seal is broken.
- Do not use premixed containers in series connections to avoid air embolism.
- Injection solution (10 mg/mL) is compatible with water for injection, sodium chloride 0.9%, dextrose 5% and 10% injection, lactated Ringer's injection.
- Injection solution diluted with compatible fluids should be used immediately or refrigerated and used within 48 h.
- For IV push: Dilute 2 mL of 10 mg/mL solution with compatible IV solution to total volume of 5 mL or 10 mL. Inject over a period of not less than 2 min.
- For IV infusion: Add 2 mL of 10 mg/mL solution to 100 mL of compatible IV solution. Infuse over 15 to 30 min.
Store tablets and suspension at controlled room temperature (59° to 86°F). Protect suspension from freezing. Discard any unused suspension after 30 days. Store premixed injection containers at controlled room temperature (77°F). Store injection vials in refrigerator (36° to 46°F). If solution freezes, bring to room temperature; allow sufficient time to solubilize all components.
Effects of ketoconazole may be decreased.
Laboratory Test Interactions
None well documented.
Arrhythmia; AV block; palpitation.
Headache (5%); dizziness (1%); generalized tonic-clonic seizures, psychic disturbances, asthenia, fatigue.
Toxic epidermal necrolysis (very rare); acne, alopecia, dry skin, flushing, pruritus, rash, urticaria.
Conjunctival injection, taste disorder, tinnitus.
Diarrhea (2%); constipation (1%); abdominal discomfort, anorexia, dry mouth, nausea, vomiting.
Agranulocytosis; leukopenia; pancytopenia; thrombocytopenia (rare).
Abnormal liver enzymes; cholestatic jaundice.
Anaphylaxis, angioedema, fever, orbital or face edema.
Arthralgia; musculoskeletal pain, including cramps.
Category B .
Excreted in breast milk.
IV use in children younger than 1 yr of age not adequately studied.OTC only
Consult health care provider for children younger than 12 years of age.
Rare cases of anaphylaxis have occurred.
Renal FunctionCrCl less than 50 mL/min
Longer intervals between doses or lower doses may be needed.
Multidose injection contains benzyl alcohol.
Symptomatic response to famotidine does not preclude gastric malignancy.
OTC chewable Pepcid AC contains phenylalanine 1.4 mg per tablet.
- Advise patient or caregiver that medication will be prepared and administered by a health care professional in a health care setting when oral therapy is not feasible. Therapy will be switched to oral therapy when the health care provider believes it is appropriate.
- Instruct patient using OTC famotidine tablets, chewable tablets, or gelcaps to carefully read package instructions regarding warnings and dosing instructions.
- Tablets and Oral Suspension
- Advise patient using tablets or suspension to take prescribed dose without regard to meals, but to take with food if stomach upset occurs.
- Advise patient or caregiver using oral suspension to shake suspension vigorously for 5 to 10 sec before measuring dose and to measure and administer prescribed dose using dosing syringe, dosing spoon, or dosing cup.
- Inform patient that antacids may be taken concurrently with famotidine.
- Instruct patient to report any of the following to health care provider: bloody or coffee ground vomit; black tarry stools; recurrent heart burn; recurrent indigestion or abdominal pain; increasing need for antacid use; bothersome side effects (eg, constipation, gas, headache).
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