Famotidine

What is Famotidine?

Famotidine is available as both a pharmacy-only and prescription-only medicine in Hong Kong, widely used to treat and prevent acid-related conditions such as heartburn, gastric ulcers, and gastroesophageal reflux disease (GERD).

As a histamine H2-receptor antagonist, or H2 blocker, it works differently from basic antacids. It chemically binds to histamine receptors on the stomach lining, actively inhibiting both the baseline and food-stimulated secretion of gastric acid.

Generic Names:

• Famotidine: The universally recognized generic name used in Hong Kong, the US, and the UK.

Global Brand Names:

Famotidine is sold under several recognizable brand names locally and internationally.

• Gaster (高斯特): Commonly available in Hong Kong hospitals and clinics for the clinical management of acid-related conditions.
• Pepcid: The original reference brand globally, often found in both prescription and pharmacy-only formulations.
• Famosan: A widely distributed brand available through various local pharmaceutical suppliers.

These names all refer to the same medication. It's important to note that while the active ingredient is the same, different countries may have different regulations and available medication formulations.

What is Famotidine used for?

Famotidine is used to relieve:

• Gastroesophageal reflux disease (GERD)
• Gastric and duodenal ulcers
• Pathological hypersecretory conditions (e.g., Zollinger-Ellison syndrome)
• Heartburn and acid indigestion

How do you use Famotidine?

Availability:

• Tablets
• Chewable tablets
• Oral liquid suspension
• Intravenous injection

Dosage Information:

• Infants/Children: Dosage is strictly weight-based (typically 0.5mg/kg to 1mg/kg per day) as directed by a doctor.
• Adults: 20mg to 40mg daily for ulcers or GERD; 10mg to 20mg for heartburn prevention.
• Elderlies: Standard adult dosing, but may require adjustments if renal impairment is present.

Suitability:

• Adults: Yes
• Children: Yes, under strict medical supervision with weight-based dosing
• Elderlies: Yes, with caution regarding kidney function
• Patients with kidney disease: Yes, but requires a 50% dose reduction or prolonged dosing intervals

Who cannot take Famotidine?

Allergies and unsuitability:

• Rare, but possible allergic reactions

Conditions where the drug should not be used:

• Known hypersensitivity to Famotidine
• Known allergy to other H2-receptor antagonists like ranitidine or cimetidine

Famotidine is generally well-tolerated, with common side effects being mild and temporary. These may include headache, dizziness, constipation, and diarrhea. Overuse or inappropriate dosing, particularly in vulnerable populations, can increase the risk of adverse reactions.

Severe side effects are rare but require immediate medical attention. In elderly patients or those with impaired kidney function, it may cause central nervous system effects such as confusion, agitation, or hallucinations. Additionally, rare cardiac arrhythmias and liver enzyme elevations have been reported, emphasizing the need to stick strictly to recommended dosages.

• Do not exceed the recommended daily dose to avoid kidney strain and central nervous system effects.
• Take 15 to 60 minutes before meals if using it to prevent food-induced heartburn.
• Consult a doctor if acid indigestion symptoms persist beyond two weeks of continuous self-treatment.
• Avoid taking at the same time as medications needing an acidic stomach environment for absorption, such as ketoconazole or iron supplements.
• Check with a healthcare provider before use if you are taking tizanidine or have severe kidney disease.

Storage information:

• Keep at room temperature between 15°C and 30°C.
• Store in a cool, dry place away from direct sunlight and moisture.
• Keep out of reach of children.

Handling instructions:

• Swallow tablets whole with a glass of water.
• Measure oral liquid suspensions carefully using the provided dosing syringe or cup, never a household spoon.
• Complete the full course of treatment prescribed by your doctor, even if symptoms improve quickly.

Where is Famotidine available in Hong Kong?

In Hong Kong, Famotidine is classified as both a "Pharmacy Only Medicine" and a "Prescription Only Medicine" depending on the dosage and formulation. Lower-dose formulations intended for short-term heartburn relief can be purchased at registered pharmacies under the direct supervision of a registered pharmacist.

Higher doses used for treating chronic conditions like GERD or active ulcers require a valid doctor's prescription. These must be purchased at registered dispensaries displaying the "Rx" logo or obtained directly from a hospital or medical clinic.