Famotidine Injection Introduction

1. General Information

Famotidine Injection is an anti - ulcer medication primarily used to treat various conditions related to excessive gastric acid secretion. The active ingredient, famotidine, belongs to the class of histamine H2 - receptor antagonists. It is formulated for intravenous administration, allowing for rapid absorption and a quick onset of action, making it suitable for acute situations where immediate control of gastric acid production is required. Famotidine Injection is typically available in vials or pre - filled syringes with different concentrations, such as 10 mg/2 mL, enabling flexible dosing according to the patient's condition.

2. Mechanism of Action

Famotidine works by selectively blocking histamine H2 receptors located on the parietal cells in the stomach lining. Histamine, when binding to these receptors, stimulates the parietal cells to secrete gastric acid. By blocking the H2 receptors, famotidine inhibits the action of histamine, thereby reducing the production and secretion of gastric acid. This reduction in gastric acid helps to relieve symptoms such as heartburn, acid indigestion, and gastric pain. Additionally, it promotes the healing of gastric and duodenal ulcers by creating a less acidic environment that is more conducive to tissue repair.

3. Indications

3.1 Gastric and Duodenal Ulcers

Famotidine Injection is indicated for the short - term treatment of active gastric and duodenal ulcers. It can significantly accelerate the healing process of ulcers by reducing the corrosive effect of gastric acid on the ulcerated tissue. For patients with acute, severe ulcers, intravenous administration of famotidine can provide rapid relief and initiate the healing process more effectively compared to oral medications in some cases.

3.2 Gastroesophageal Reflux Disease (GERD)

In patients with GERD, where stomach acid flows back into the esophagus, causing heartburn and potential damage to the esophageal lining, famotidine helps to control the amount of gastric acid secreted. This alleviates the symptoms of GERD and reduces the risk of complications such as esophagitis (inflammation of the esophagus) and esophageal ulcers.

3.3 Erosive Esophagitis

It is also used in the treatment of erosive esophagitis, which is a more severe form of esophagus damage due to prolonged exposure to gastric acid. By decreasing gastric acid production, famotidine supports the healing of the damaged esophageal mucosa and relieves associated pain and discomfort.

3.4 Prevention of Stress - related Gastric Mucosal Lesions

In critically ill patients, stress can lead to the development of gastric mucosal lesions due to increased gastric acid secretion and reduced blood flow to the stomach. Famotidine Injection can be administered prophylactically to prevent the occurrence of these lesions, protecting the integrity of the gastric mucosa.

4. Dosage and Administration

4.1 Adult Dosage

For the treatment of active gastric and duodenal ulcers, the typical adult dose is 20 mg administered intravenously every 12 hours for up to 8 weeks. In cases of severe or refractory ulcers, the dose may be adjusted based on the patient's response. For the treatment of GERD and erosive esophagitis, the same 20 mg every 12 - hour dosing regimen is usually recommended, with the treatment duration depending on the severity of the condition. For the prevention of stress - related gastric mucosal lesions in critically ill patients, 20 mg is often administered intravenously every 12 hours. The injection should be administered slowly over at least 2 minutes to avoid adverse effects.

4.2 Pediatric Dosage

In pediatric patients, the dosage of famotidine is calculated based on body weight. For children older than 1 month, the recommended dose is 0.25 - 0.5 mg/kg administered intravenously every 12 hours. However, careful consideration of the child's age, weight, and overall health condition is necessary, and close monitoring for potential side effects is essential.

5. Precautions and Contraindications

5.1 Contraindications

Famotidine Injection is contraindicated in patients with a known hypersensitivity to famotidine or any of the components of the formulation. It should also be used with caution in patients with severe renal impairment, as the drug is primarily excreted by the kidneys. In such cases, the dosage may need to be significantly reduced, and regular monitoring of renal function and drug levels is required.

5.2 Drug Interactions

Famotidine may interact with certain drugs. For example, it can increase the blood levels of drugs such as phenytoin and theophylline by inhibiting their metabolism in the liver. On the other hand, antacids may decrease the absorption of famotidine if taken concurrently. Therefore, when famotidine is prescribed, healthcare providers need to carefully review the patient's medication list to identify and manage potential drug interactions.

5.3 Special Populations

In elderly patients, the risk of adverse effects may be increased due to age - related changes in organ function, especially renal function. Dosage adjustment and more frequent monitoring are often necessary. Pregnant and breastfeeding women should use famotidine Injection with caution, as the safety of the drug during these periods has not been fully established. Adequate evaluation of the benefits and risks to both the mother and the fetus/infant is required before administration.

6. Adverse Reactions

The most common adverse reactions associated with Famotidine Injection include headache, dizziness, constipation, diarrhea, and nausea. These side effects are generally mild to moderate and often resolve on their own. Less common but more serious adverse reactions may include confusion, hallucinations, especially in elderly patients or those with renal impairment. Rarely, blood disorders such as thrombocytopenia (low platelet count) and agranulocytosis (low white blood cell count) may occur. In addition, some patients may experience allergic reactions, ranging from mild rashes to severe anaphylaxis. If any unusual or severe adverse reactions occur, immediate medical attention should be sought.

In conclusion, Famotidine Injection is an important therapeutic option for managing various gastric acid - related disorders. When used appropriately, with careful consideration of dosage, potential drug interactions, and patient - specific factors, it can effectively relieve symptoms, promote ulcer healing, and prevent related complications while minimizing the risk of adverse effects.