Full Prescribing Info
FC Tablet: H2bloc Tablet contains 20 mg Famotidine.
Injection: H2bloc IV/IM contains 20 mg Famotidine.
Famotidine is a histamine H2-receptor antagonist which reduces the production of acid in the stomach.
Pharmacology: Pharmacodynamics: Mechanism of Action: Famotidine is a histamine receptor blocking agent which competitively inhibits the action of histamine on the H2 receptors of parietal cells. The primary pharmacologic activity of famotidine is inhibition of gastric juice secretion. Both the acid concentration and volume of gastric secretion are suppressed by famotidine, while changes in pepsin secretion are proportional to volume output. Famotidine inhibited basal and nocturnal gastric secretion, as well as secretion stimulated by food and pentagastrin.
Pharmacokinetics: Famotidine is incompletely absorbed, with an oral bioavailability of 40 to 50%. Food may slightly enhance and antacids may slightly decrease the bioavailability of famotidine, but these alterations do not appear to be clinically significant. After oral doses, peak plasma levels occur in 1 to 3 hours. Plasma levels after multiple doses are similar to those after single doses.
After intravenous (IV) injection of a single 20 mg dose of famotidine, peak plasma concentrations of 272 ng/mL occur within 20 minutes and decrease to 163, 98, 64, 25, and 11 ng/mL at 1, 2, 4, 8, and 12 hours, respectively, after the dose.
After IV administration, inhibition of gastric acid secretion is apparent within one hour and peak inhibition occurs within 0.5 to 3 hours or 1 to 4 hours following IV or oral administration, respectively. The duration of inhibition of nocturnal gastric acid secretion is 10 to 15 hours. In a study in healthy individuals who were hypersecretors of gastric acid (basal gastric acid output of 5 or more mEq/hour), maximal inhibition of gastric acid secretion was 97.4, 99.7, or 99.4%, 2 to 4 hours and 73.8, 77.2, or 83.3%, 12 hours following a single famotidine dose of 10 or 20 mg IV or 20 mg orally, respectively.
The apparent volume of distribution of the drug is 1.1 to 1.4 L/kg in adults and does not appear to be altered substantially in patients with renal dysfunction. In children 1 to 15 years old, a volume of distribution of 1.5 to 2.07 L/kg has been reported. The drug is 15 to 20% protein bound.
Famotidine is metabolized in the liver to famotidine S-oxide (S-famotidine). The metabolite does not appear to inhibit gastric acid secretion. Orally administered famotidine undergoes minimal first pass metabolism in the liver. The elimination half-life of famotidine averages 2.5 to 4 hours in adults with normal renal function. An elimination half-life of 2.3 to 3.38 hours has been reported in children 1 to 15 years old.
The elimination of famotidine does not appear to be affected substantially by age in adults, but is prolonged in patients with renal impairment; adjustment of dosage or dosing interval may be necessary to avoid excess accumulation of the drug in patients with moderate to severe renal impairment. In adults with creatinine clearances of 10 mL or less per minute, the elimination half-life of the drug may exceed 20 hours, with an elimination half-life of about 24 hours in anuric patients. In adults with normal renal function and those with creatinine clearances of 60 to 90, 30 to 60, or less than 30 mL/minute per 1.48 m2, the plasma half-life in the distribution phase was not affected substantially by renal function, averaging 0.18, 0.23, 0.25, or 0.24 hours, respectively; the half-life in the terminal elimination phase average 2.6, 2.9, 4.7, or 12 hours, respectively.
Famotidine is excreted principally in urine via glomerular filtration and tubular secretion. Approximately 25 to 30% or 65 to 80% of a dose is excreted unchanged in urine within 24 hours following oral or IV administration, respectively and approximately 13 to 49% or 52 to 82% of a single 40 mg oral or IV dose, respectively, is excreted within 72 hours.
Tablet: Short-term treatment of the following conditions: Active duodenal ulce, Active benign gastric ulcer, Gastroesophageal reflux disease (GERD) with or without esophagitis; Maintenance therapy of the following conditions: Duodenal ulcer after healing of an active ulcer, GERD; and treatment of pathological hypersecretory conditions (e.g., Zollinger-Ellison syndrome, multiple endocrine adenomas).
Injection: For some hospitalized patients with pathological hypersecretory conditions or intractable ulcers; For the short-term treatment of the following conditions when oral medication is not feasible: Treatment and maintenance of active duodenal ulcer, Active benign gastric ulcer, Treatment and maintenance therapy of GERD, Pathological hypersecretory conditions (e.g., Zollinger-Ellison syndrome, multiple endocrine adenomas) and Upper gastrointestinal bleeding (due to esophagitis)
Dosage/Direction for Use
Tablet: Ulcer: Adults: Treatment: Usual Recommended Dose: 40 mg (2 tablets) daily at bedtime. Treatment may last 4-8 weeks depending on patient's response.
A dose of 20 mg twice daily has also been given.
Maintenance Dose: 20 mg daily at bedtime.
Children 1-16 years: Initial dose of 0.5 mg/kg per day, either in a single dose at night or in two divided doses; up to 40 mg per day may be given..
GERD: Adults: Treatment: 20 mg two times a day (one tablet in the morning and one tablet at bedtime) for 6 to 12 weeks, or up to 40 mg two times a day if there is esophageal erosion or ulceration.
Maintenance dose: 2
0 mg two times a day (one tablet in the morning and one tablet at bedtime).
Pathological Hypersecretory Conditions:
20 mg every six hours, increased as necessary and continued as long as it is clinically indicated; doses up to 800 mg per day have been used.
Patients with renal impairment:
To avoid excess accumulation of the drug in patients with moderate and severe renal impairment, the dose of famotidine may be reduced to half the dose or the dosing may be prolonged to 36 to 48 hours as indicated by the patient’s clinical response. Dialysis patients should also take half the recommended dose. Famotidine tablets should be administered at the end of dialysis or later since some of the active ingredient is removed by dialysis.
Injection: Recommended Adult Parenteral Dose:
20 mg every 12 hours.
Suggested Parenteral Famotidine Starting Dose in Children 1 to 16 years old:
An initial dose of 0.25 mg/kg is suggested for GERD, given by injection over at least 2 minutes or as an infusion over 15 minutes, and repeated every 12 hours. Up to 40 mg per day may be given. Or, as prescribed by a physician
Administration: Tablet: If the patient missed a dose, take the next dose as scheduled. Do not double the dose. Do not take more than the recommended dose.
Injection: Famotidine injection should be administered by slow IV injection (not <2 min), by slow IV infusion (15-30 min) or by IM injection.
Dosage must be adjusted based on age, patient's response and/or gastric or esophageal pH determination and endoscopy to meet individual patient requirement.
Parenteral famotidine should be shifted to oral famotidine as soon as feasible.
Inspect the solution for particulate matter and discoloration before administration.
Preparation and Directions for Reconstitution:
IV Injection: Dissolve powder in 20 mL physiological saline injection or 5% dextrose injection.
IV Infusion: Dissolve powder in 20 mL physiological saline injection or 5% dextrose injection and dilute further to 100 mL using either IV fluid.
IM Injection: Dissolve powder in 1-1.5 mL sterile water for injection.
The adverse reactions in overdose cases are similar to the adverse reactions encountered in normal clinical experience. Doses of up to 800 mg/day have been given to adult patients with pathological hypersecretory conditions with no serious adverse effects. In the event of overdosage, treatment should be symptomatic and supportive. Unabsorbed material should be removed from the gastrointestinal tract, the patient should be monitored, and supportive therapy should be employed.
Hypersensitivity to famotidine, other H2-receptor antagonists or other ingredients in the product
Special Precautions
General: Do not administer famotidine tablets in cases of minor gastrointestinal complaints.
In case of long-term treatment with high dosage, monitoring of blood count and liver function is recommended.
Patients with Renal Impairment: Central nervous system (CNS) adverse effects have been reported in patients with moderate (creatinine clearance <50 mL/min) and severe (creatinine clearance <10 mL/min) renal impairment. Consequently, longer intervals between doses or lower doses should be used in patients with moderate to severe renal impairment (see Dosage and Administration).
Use in Ulcers: Gastric malignancy should be excluded prior to initiation of therapy of gastric ulcer with famotidine. Symptomatic response of gastric ulcer to therapy with famotidine does not preclude the presence of gastric malignancy.
In patients with duodenal ulcers and benign gastric ulcers, the H. pylori status should be determined. Wherever possible, patients with H. pylori should undergo eradication therapy to eliminate the bacteria.
In case of long-standing ulcer disease, abrupt withdrawal after symptom relief should be avoided.
Risk of Community- or Hospital-Acquired Pneumonia:
Agents that elevate gastric pH may increase the risk of community- or hospital-acquired pneumonia. It should be considered that certain patients are at increased risk of developing infections and in these patients pneumonia may be associated with increased mortality. Gastric acid-suppressive drugs should be used in patients in whom community- or hospital-acquired pneumonia may be severe only when clearly needed and the lowest effective dose should be employed.
Effects on Ability to Drive and Use Machines: Famotidine may cause certain adverse effects such as dizziness, confusion, hallucinations, and headache.
Use In Pregnancy & Lactation
Pregnancy: Pregnancy Category B. There are no adequate or well-controlled studies in pregnant women. Famotidine is not recommended for use in pregnancy and should be prescribed only if clearly needed. Before a decision is made to use famotidine, the physician should weigh the potential benefits from the medicine against the possible risks involved.
Lactation: Famotidine is excreted in human milk. Decision should be made whether to discontinue famotidine or breastfeeding since famotidine may cause potential serious adverse reactions to the baby.
Adverse Reactions
Famotidine is generally well tolerated; most adverse effects have been mild and transient.
The most frequently reported adverse effects (> 1%) are constipation, diarrhea, dizziness, and headache.
Less common adverse effects (≤ 1% of patients) include: Blood and Lymphatic System: Agranulocytosis, eosinophilia, leukocytosis, leukopenia, neutropenia, pancytopenia, prolonged erythrocyte sedimentation rate, thrombocytopenia.
Immune System: Anaphylaxis, angioedema, conjunctival congestion, orbital or facial edema, rash, urticaria.
Psychiatric: Disorientation, insomnia, reversible psychic disturbances (reversible in cases for which follow-up was obtained, including hallucinations, confusions, agitation, depression, anxiety, decreased libido).
Nervous System: Paresthesia, seizures/convulsions (epileptic, gran mal, particularly in patients with renal impairment), somnolence, taste disorder.
Cardiovascular Effects: Arrhythmia, AV block, bradycardia, hypertension, palpitation, prolonged QT interval in patients with impaired renal function.
Respiratory, Thoracic and Mediastinal: Bronchospasm, interstitial pneumonia.
Gastrointestinal: Abdominal discomfort or distension, belching, dry mouth, dysgeusia, flatulence, heartburn, vomiting.
Hepatobiliary: Cholestatic jaundice, hepatitis, hepatomegaly, intrahepatic cholestasis (visible sign: jaundice), liver enzyme abnormalities (alanine transaminase, aspartate transaminase, gamma-glutamyl transpeptidase, alkaline phosphatase, bilirubin).
Skin and Subcutaneous Tissue: Acne, alopecia, dry skin, flushing, pruritus, Stevens-Johnson syndrome, toxic epidermal necrolysis.
Musculoskeletal: Musculoskeletal pain including muscle cramps, arthralgia.
Reproductive and Breast: Gynecomastia, impotence, menstrual abnormalities.
General Disorders and Administration Site Conditions: Asthenia, chest tightness, fatigue, fever.
Others: Anorexia, changes in serum protein or cholesterol concentrations, increase in blood urea nitrogen or serum creatinine, tinnitus.
Additional Undesirable Effect for Injection Use: General Disorders and Administration Site Conditions: Transient irritation at the injection site.
Drug Interactions
No drug interactions of clinical importance have been identified.
Antacids: May reduce famotidine uptake and cause lower levels of famotidine. Famotidine should be administered 1 to 2 hours before antacids.
Atazanavir: Alterations of gastric pH may affect the bioavailability of certain drugs, resulting in reduced absorption of atazanavir.
Ketoconazole and Itraconazole: Absorption of these drugs may be reduced by famotidine; give 2 hours before famotidine administration.
Probenecid: Inhibits renal tubular secretion of famotidine and causes a 50% increase in plasma levels of famotidine. Concomitant use should be avoided.
Sucralfate: Inhibits absorption of famotidine; give 2 hours after famotidine administration Famotidine does not interact with cytochrome P450-linked drug metabolizing enzyme system.
Compounds metabolized by this system which have been tested in man include warfarin, propranolol, theophylline, phenytoin, diazepam, aminopyrine, and antipyrine. Indocyanine green as an index of hepatic blood flow and/or hepatic drug extraction has been tested and no significant effects have been found.
Tell the doctor if patient is taking other medicines, including vitamins, supplements, and herbal medicines.
Caution For Usage
Stability: Injection: Famotidine should be used within 48 hrs after reconstitution; store at room temperature or keep refrigerated.
Store at temperatures not exceeding 30°C. Injection: Keep in hermetic container.
ATC Classification
A02BA03 - famotidine ; Belongs to the class of H2-receptor antagonists. Used in the treatment of peptic ulcer and gastro-oesophageal reflux disease (GERD).
FC tab:Non-Rx;Powd for inj:Rx
FC tab 20 mg (yellow, round, biconvex, plain on both sides) x 50's. Powd for inj 20 mg (lyophilized in clear, colorless vial) x 10's.
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