Zantin (Tablets, Solution) Instructions for Use

ATC Code

A02BA02 (Ranitidine)

Active Substance

Ranitidine (Rec.INN registered by WHO)

Clinical-Pharmacological Group

Histamine H₂-receptor blocker. Antiulcer drug

Pharmacotherapeutic Group

H2 histamine receptor blocker

Pharmacological Action

Histamine H₂-receptor blocker. Suppresses basal and histamine-, gastrin-, and acetylcholine-stimulated (to a lesser extent) secretion of hydrochloric acid. It contributes to an increase in the pH of gastric contents and reduces pepsin activity. The duration of action of ranitidine after a single dose is 12 hours.

Pharmacokinetics

After oral administration, Ranitidine is rapidly absorbed from the gastrointestinal tract. Food and antacids have a slight effect on the extent of absorption. It undergoes the first-pass effect through the liver. C_max in plasma is reached 2 hours after a single oral dose. After intramuscular injection, it is rapidly and almost completely absorbed from the injection site. C_max is reached in 15 minutes.

Protein binding is 15%. V_d is 1.4 L/kg. Ranitidine is excreted in breast milk.

T_1/2 is 2-3 hours. About 30% of the administered dose is excreted unchanged in the urine. The excretion rate decreases with impaired liver or kidney function.

Indications

Gastric and duodenal ulcer in the acute phase; prevention of peptic ulcer exacerbations; symptomatic ulcers; erosive and reflux esophagitis; Zollinger-Ellison syndrome; prevention of “stress” gastrointestinal ulcers, postoperative ulcers, recurrence of bleeding from the upper gastrointestinal tract; prevention of gastric juice aspiration during operations under anesthesia.

ICD codes

Dosage Regimen

Tablets, Solution

The dosage is set individually. Orally for the treatment of adults and children over 14 years of age, it is used in a daily dose of 300-450 mg; if necessary, the daily dose can be increased to 600-900 mg; the frequency of administration is 2-3 times/day. For the prevention of disease exacerbations, 150 mg/day is used at bedtime. The duration of treatment is determined by the indications for use. For patients with renal failure with a creatinine level of more than 3.3 mg/100 ml – 75 mg 2 times/day.

Intravenously or intramuscularly – 50-100 mg every 6-8 hours.

Adverse Reactions

From the cardiovascular system in isolated cases (with intravenous administration) – AV block.

From the digestive system rarely – diarrhea, constipation; in isolated cases – hepatitis.

From the central nervous system rarely – headache, dizziness, feeling of tiredness, blurred vision; in isolated cases (in severely ill patients) – confusion, hallucinations.

From the hematopoietic system rarely – thrombocytopenia; with long-term use in high doses – leukopenia.

From metabolism rarely – a slight increase in serum creatinine at the beginning of treatment.

From the endocrine system with long-term use in high doses, an increase in prolactin content, gynecomastia, amenorrhea, impotence, and decreased libido are possible.

From the musculoskeletal system very rarely – arthralgia, myalgia.

Allergic reactions rarely – skin rash, urticaria, angioedema, anaphylactic shock, bronchospasm, arterial hypotension.

Other rarely – recurrent parotitis; in isolated cases – hair loss.

Contraindications

Pregnancy, lactation (breastfeeding), hypersensitivity to ranitidine.

Use in Pregnancy and Lactation

Adequate and well-controlled studies on the safety of ranitidine use during pregnancy have not been conducted, therefore its use during pregnancy is contraindicated.

If it is necessary to use ranitidine during lactation, breastfeeding should be discontinued.

Use in Renal Impairment

Use with caution in patients with impaired renal excretory function.

Pediatric Use

Clinical data on the safety of ranitidine use in pediatrics are limited.

Special Precautions

Use with caution in patients with impaired renal excretory function.

Before starting treatment, it is necessary to exclude the possibility of a malignant disease of the esophagus, stomach, or duodenum.

During long-term treatment of debilitated patients under stress conditions, bacterial lesions of the stomach with subsequent spread of infection are possible.

Abrupt discontinuation of ranitidine is not recommended due to the risk of peptic ulcer recurrence. The effectiveness of preventive treatment for peptic ulcer is higher when ranitidine is taken in courses of 45 days in the spring-autumn period than with continuous use. Rapid intravenous administration of ranitidine in rare cases causes bradycardia, usually in patients predisposed to cardiac arrhythmias.

There are isolated reports that Ranitidine may contribute to the development of an acute attack of porphyria, therefore its use should be avoided in patients with a history of acute porphyria.

During the use of ranitidine, distortions of laboratory test data are possible: an increase in the level of creatinine, activity of GGT and liver transaminases in blood plasma.

In cases where Ranitidine is used in combination with antacids, the interval between taking antacids and ranitidine should be at least 1-2 hours (antacids may cause impaired absorption of ranitidine).

Clinical data on the safety of ranitidine use in pediatrics are limited.

Drug Interactions

With simultaneous use with antacids, a decrease in the absorption of ranitidine is possible.

With simultaneous use with anticholinergic agents, memory and attention impairment in elderly patients is possible.

It is believed that histamine H₂-receptor blockers reduce the ulcerogenic effect of NSAIDs on the gastric mucosa.

With simultaneous use with warfarin, a decrease in the clearance of warfarin is possible. A case of hypoprothrombinemia and bleeding in a patient receiving warfarin has been described.

With simultaneous use with bismuth tripotassium dicitrate, an undesirable increase in bismuth absorption is possible; with glibenclamide – cases of hypoglycemia have been described; with ketoconazole, itraconazole – the absorption of ketoconazole, itraconazole is reduced.

With simultaneous use with metoprolol, an increase in plasma concentration and an increase in AUC and T_1/2 of metoprolol are possible.

With simultaneous use with high doses of sucralfate (2 g), impaired absorption of ranitidine is possible.

With simultaneous use with procainamide, a decrease in the renal excretion of procainamide is possible, leading to an increase in its plasma concentration.

There is evidence of an increase in the absorption of triazolam with its simultaneous use, apparently due to a change in the pH of the gastric contents under the influence of ranitidine.

It is believed that with simultaneous use with phenytoin, an increase in the plasma concentration of phenytoin and an increased risk of toxicity are possible.

With simultaneous use with furosemide, a moderately pronounced increase in the bioavailability of furosemide is observed.

A case of ventricular arrhythmia (bigeminy) has been described with simultaneous use with quinidine; with cisapride – a case of cardiotoxicity has been described.

A slight increase in the plasma concentration of cyclosporine when used simultaneously with ranitidine cannot be ruled out.

Storage Conditions

Store at 2°C (36°F) to 25°C (77°F). Keep in original packaging, protected from light. Keep out of reach of children.

Dispensing Status

Rx Only

Important Safety Information

This information is for educational purposes only and does not replace professional medical advice. Always consult your doctor before use. Dosage and side effects may vary. Use only as prescribed.