PharmacodynamicsPharmacological action - antiulcer. Blocks histamine H2 receptors, inhibits basal and stimulated secretion of hydrochloric acid; inhibits pepsin activity. Not completely absorbed from the gastrointestinal tract, bioavailability is 40–45%, increases under the influence of food and decreases with the use of antacids. Binding to plasma proteins - 15–20%. Cmax is reached within 1-3 hours. 30–35% is metabolized in the liver with the formation of S-oxide and excreted by the kidneys by glomerular filtration and tubular secretion. 25–30% of the dose taken orally and 65–70% of the administered iv are found in the urine unchanged. T1 / 2 from plasma - 2.5–3 hours, in patients with severe renal failure (creatinine Cl <10 ml / min) may increase to 20 hours (dose adjustment required). Passes through the placenta and excreted in breast milk.After oral administration, the action begins after 1 hour, reaches a maximum within 3 hours and lasts 10-12 hours. Under the conditions of iv administration, the maximum effect develops after 30 minutes. A single dose (10 and 20 mg) suppresses secretion for 10-12 hours.
PharmacokineticsTreatment and prevention of exacerbations of peptic ulcer of the stomach and duodenum; treatment and prevention of symptomatic ulcers of the stomach and duodenum (associated with NSAIDs, stressful, postoperative); erosive gastroduodenitis, reflux esophagitis, Zollinger-Ellison syndrome, bleeding from the upper gastrointestinal tract (as part of complex treatment) and prevention of recurrence of bleeding from the upper gastrointestinal tract, systemic mastocytosis, polyendocrine adenomatosis, prevention of aspiration of gastric juice during general anesthesia (Mend's syndrome). Functional dyspepsia associated with increased secretory function of the stomach. Symptomatic treatment of dyspepsia associated with increased acidity of gastric juice (including heartburn, sour belching).
ContraindicationsHypersensitivity, pregnancy, breastfeeding.
Pregnancy and lactationThe FDA category of action for the fetus is B.
Side effectsOn the part of the digestive tract: dry oral mucosa, decreased appetite, nausea, vomiting, abdominal pain, increased activity of hepatic transaminases, constipation, diarrhea, jaundice; hepatocellular, cholestatic or mixed hepatitis, acute pancreatitis.From the cardiovascular system and blood (hematopoiesis, hemostasis): decreased blood pressure, bradycardia, AV block, arrhythmia, vasculitis, neutropenia, leukopenia, thrombocytopenia, hemolytic anemia, agranulocytosis, pancytopenia; with parenteral administration, asystole.From the nervous system and sensory organs: headache, asthenia, drowsiness, insomnia, fatigue, anxiety, depression, nervousness, psychosis, dizziness, confusion, hallucinations, hyperthermia, tinnitus.From the genitourinary system: with prolonged use of large doses - a decrease in potency and libido.From the musculoskeletal system: arthralgia, myalgia.Allergic reactions: urticaria, skin rash, itching, bronchospasm, angioedema, multiforme erythema, exfoliative dermatitis, Stevens-Johnson syndrome, toxic epidermal necrolysis, anaphylactic shock.Other: bronchospasm, dry skin, alopecia, gynecomastia; local reactions - irritation at the injection site.
InteractionWith the simultaneous administration of famotidine and ketoconazole, the absorption of ketoconazole may decrease. In the case of using famotidine with antacids, the interval between their intake should be at least 1-2 hours.
Dosage and administrationInside, without chewing, drinking plenty of water. Adults: With peptic ulcer of the stomach and duodenum in the acute phase, symptomatic ulcers, erosive gastroduodenitis, 20 mg 2 times / day or 40 mg 1 time / day is usually prescribed. If necessary, the daily dose can be increased to 80-160 mg. The course of treatment is 4-8 weeks. With dyspepsia associated with increased secretory function of the stomach, 20 mg is prescribed 1-2 times / day. In order to prevent recurrence of peptic ulcer, 20 mg is prescribed 1 time / day before bedtime. With reflux esophagitis - 20-40 mg 2 times / day for 6-12 weeks. With Zollinger-Ellison syndrome, the dose of the drug and the duration of the course of treatment are set individually. The initial dose is usually 20 mg every 6 hours and can be increased to 160 mg every 6 hours. For the prevention of aspiration of gastric juice with general anesthesia, 40 mg is prescribed in the evening and / or in the morning before surgery. Famotidine tablets should be swallowed without chewing, drinking plenty of water. In renal failure, if the QC is less than 30 ml / min or the creatinine content in the blood serum is more than 3 mg / 100 ml, the daily dose should be reduced to 20 mg. Children over 3 years old: With peptic ulcer of the stomach and duodenum in the exacerbation phase, reflux esophagitis Famotidine is prescribed for children weighing more than 10 kg at a rate of 2 mg / kg / day, divided into 2 doses or 20 mg 2 times / day, but not more than 40 mg / day
OverdoseSymptoms: aggravation of side effects. Treatment: gastric lavage, symptomatic or supportive therapy.
Special instructionsIn patients with impaired renal function (creatinine Cl below 30 ml / min), the daily dose is reduced to 20 mg. Children are not recommended to prescribe the drug. In the treatment of peptic ulcer of the stomach and duodenum, it is necessary to exclude the presence of a malignant tumor in the patient (examination of a biopsy from an ulcer area). Use with caution in case of impaired liver function.