Ranitidine blocks the histamine H2-receptors of parietal cells of the gastric mucosa, reduces basal and stimulated secretion of hydrochloric acid, cause irritation of the baroreceptors, the food load, the action of hormones and biogenic stimulators (gastrin, histamine, pentagastrin). Ranitidine reduces the amount of gastric juice and the concentration of hydrochloric acid in it, increases the pH of stomach contents which leads to lower activity of pepsin. Following oral administration at therapeutic doses, did not affect prolactin. Inhibits microsomal enzymes.
The duration of action after a single dose – up to 12 hours.
Quickly absorbed, eating does not affect the degree of absorption. When ingestion bioavailability of ranitidine is approximately 50%.Maximum plasma concentrations are reached 2-3 hours after ingestion. Communication with the plasma protein does not exceed 15%. Slightly metabolized in the liver to form desmetilranitidina and ranitidine S-oxide. It has the effect of “first pass” through the liver. The rate and extent of elimination little dependent on the state of the liver. The half-life after oral administration – 2.5 hours, with creatinine clearance 20-30 ml / min – 8-9 hours. Write mainly in the urine (60-70% as unchanged – 35%), a small amount – with the feces.
When administered intravenously, 93% of the dose is excreted in the urine, with 70% of ranitidine appears unchanged. Poorly penetrates the blood-brain barrier. It penetrates through the placenta. Provided with breast milk (concentration in the breast milk of lactating women is higher than in plasma).
Treatment and prevention of relapse of gastric ulcer and duodenal ulcer; stomach ulcers and 12 duodenal ulcers associated with nonsteroidal anti-inflammatory drugs (NSAIDs); reflux esophagitis, erosive esophagitis; Zollinger-Ellison syndrome; treatment and prevention of post-operative, “stress” ulcers of the upper gastrointestinal tract; prevention of recurrent bleeding from the upper gastrointestinal tract;prevention of aspiration of gastric juice in operations under general anesthesia (Mendelson’s syndrome).
The suspension testosterone for intravenous and intramuscular administration of
the prevention of bleeding during “stress ulcers” and recurrent bleeding in patients with gastric ulcer and duodenal ulcer; prevention of Mendelson’s syndrome.
Hypersensitivity to ranitidine or other components of the preparation. Pregnancy, lactation. Children under 12 years old.
Be wary – kidney and / or liver failure, cirrhosis with portosystemic encephalopathy in history, acute porphyria (including a history..).
DOSAGE AND ADMINISTRATION
taken without regard to meals, not liquid, squeezed small amounts of liquid.
Adults and children over 12 years:
Peptic ulcer and 12 duodenal ulcer. For the treatment of exacerbations appoint 150 mg 2 times a day (morning and evening) or 300 mg at night. If needed – 300 mg 2 times a day. Duration of treatment – 4-8 weeks. For the prevention of relapse appoint 150 mg at night, smoking patients – 300 mg at night.
Ulcers associated with NSAID intake. Prescribe 150 mg 2 times daily or 300 mg at night for 8-12 weeks. Prevention of the formation of ulcers when taking NSAIDs – 150 mg 2 times a day.
Postoperative and “stressful” ulcer. Assign 150 mg 2 times a day for 4-8 weeks.
Erosive reflux esophagitis. Assign to 150 mg 2 times daily or 300 mg at night. If necessary, the dose may be increased up to 150 mg four times a day. The course of treatment – 8-12 weeks. Long-term prophylactic therapy -150 mg 2 times a day.
Zollinger-Ellison syndrome. The initial dose of 150 mg three times a day, the dose can be increased if necessary. The duration of the treatment – as needed.
Prophylaxis of recurrent bleeding. 150 mg 2 times a day. The duration of the treatment – as needed.
Prophylaxis of Mendelson’s syndrome. Assign a dose of 150 mg 2 hours before anesthesia, and also 150 mg the previous evening.
In the presence of concomitant hepatic dysfunction may require dose reduction.
For patients with renal failure at a creatinine clearance less than 50 mL / min, the recommended dose is 150 mg per day.
The suspension testosterone for intravenous and intramuscular administration of the prevention of bleeding during “stress ulcers” and recurrent bleeding in patients with gastric ulcer and duodenal ulcer. Intramuscular injection: 50 mg (2 mL) every 6-8 hours. Intravenous injection: 50 mg (2 mL) every 6-8 hours. The contents of ampoules (50 mg) was diluted with 0.9% sodium chloride or dextrose for injection to a total volume of 20 ml, and slowly administered over 5 minutes. The drug is administered parenterally to until oral intake is impossible.
Prevention of Mendelson’s syndrome. 50 mg intramuscularly or intravenously 45-60 minutes prior to general anesthesia.
In patients with renal failure at a creatinine clearance less than 50 mL / min, the recommended unit dose is 25 mg.
From the digestive system: nausea, dry mouth, constipation, vomiting, diarrhea, abdominal pain, increased activity of “liver” transaminases, hepatocellular, cholestatic or mixed hepatitis, acute pancreatitis.
From the side of hematopoiesis: leukopenia, thrombocytopenia, agranulocytosis, pancytopenia, hypo- and aplasia of the bone marrow, immune hemolytic anemia.
Since the cardiovascular system: reduction in blood pressure, bradycardia, arrhythmias, atrio-ventricular block; asystole (for parenteral administration).
From the nervous system: fatigue, drowsiness, headache, dizziness, confusion, tinnitus, irritability, hallucinations (mainly in the elderly and critically ill patients), involuntary movements.
From the senses : blurred vision, paresis of accommodation.
From the musculoskeletal system: arthralgia, myalgia.
From endocrine system: hyperprolactinemia, gynecomastia, amenorrhea, decreased libido, impotence.
Allergic reactions: urticaria, skin rash, angioedema, anaphylactic shock, bronchospasm , exudative erythema multiforme.
Other: alopecia, hypercreatininemia, increasing glutamattranspeptidazy activity, acute porphyria.
symptoms: convulsions, bradycardia, ventricular arrhythmias. Treatment: symptomatic. With the development of convulsions – diazepam intravenously, bradycardia or ventricular arrhythmias – atropine, lidocaine. Hemodialysis – effective.
Tobacco smoking reduces the effectiveness of ranitidine. Increases concentration of metoprolol in the blood serum at 50%, while the half-life of metoprolol is increased from 4.4 to 6.5 h. By increasing the pH of stomach contents while receiving may decrease the absorption of itraconazole and ketoconazole.
It inhibits hepatic metabolism phenazone, aminophenazone, diazepam, hexobarbital, propranolol, diazepam, lidocaine, phenytoin, theophylline, aminophylline, indirect anticoagulants, glipizide, buformina, metronidazole, calcium antagonists. Drugs that suppress the bone marrow, increasing the risk of developing neutropenia.
In an application with antacids, sucralfate, in high doses may slow the absorption of ranitidine, so the interval between administration of these medications must be at least 2 hours.
ranitidine treatment can mask symptoms associated with carcinoma of the stomach, so before starting treatment to rule out cancer-ulcer. Ranitidine is undesirable sharply cancel ( “ricochet” syndrome).
With long-term treatment of patients with weakened under stress may be bacterial lesions of the stomach and then spread the infection. The safety and efficacy of ranitidine in children have not been established up to 12 years.
In the period of treatment should refrain from activities potentially hazardous activities that require high concentration and psychomotor speed reactions.
H2-blockers gistaminoretseptorov be taken by 2 hours after the administration of ketoconazole or itraconazole avoid significant reduction of absorption. Receiving ranitidine may cause false positive reactions to conduct tests for urinary protein.
H2 blockers gistaminoretseptorov may counteract the effects of pentagastrin and histamine on acid-forming function of the stomach, so in the preceding test, is not recommended for H2 blockers gistaminoretseptorov within 24 hours.
H2 blockers gistaminoretseptorov can inhibit the skin reaction to histamine, thus leading to false positive results (prior to diagnostic skin tests to detect immediate allergic skin reaction such as the use of blockers of H-gistaminoretseptorov recommended stop).