Zinetac

Description

Zinetac Tablet (Ranitidine)

Zinetac Tablet contains Ranitidine, a medication that reduces stomach acid production by blocking histamine H2-receptors in the stomach lining.

Indications

Zinetac Tablet is prescribed for the treatment and prevention of various gastrointestinal conditions, including:

• Acid-Related Conditions:
  • Dyspepsia (indigestion)
  • Gastroesophageal Reflux Disease (GERD) and Erosive Esophagitis (inflammation of the esophagus due to acid)
  • Benign Gastric and Duodenal Ulceration (non-cancerous ulcers in the stomach and duodenum)
  • Zollinger-Ellison Syndrome (a condition causing excessive stomach acid secretion)
• Prophylaxis (Prevention):
  • Acid Aspiration during general anesthesia
  • NSAID-associated Ulceration (ulcers caused by non-steroidal anti-inflammatory drugs)
  • Stress Ulceration of the upper gastrointestinal (GI) tract
• Infection:
  • H. pylori infection (as part of a multi-drug regimen)

Dosage and Administration

Zinetac can be taken with or without food.

Adult Oral Dose

• Benign Gastric and Duodenal Ulceration:
  • Initial: 300 mg once daily at bedtime OR 150 mg twice daily for 4-8 weeks. For duodenal ulcers, 300 mg twice daily for 4 weeks may enhance healing.
  • Maintenance: 150 mg once daily at bedtime.
  • Maximum: 300 mg twice daily.
• Hypersecretory Conditions (e.g., Zollinger-Ellison Syndrome):
  • Initial: 150 mg two or three times daily, adjusted as needed based on response.
  • Maximum: 6 grams daily.
• Gastroesophageal Reflux Disease (GERD):
  • 150 mg twice daily or 300 mg at bedtime for up to 8 weeks.
  • Severe Cases: May be increased to 150 mg four times daily for up to 12 weeks.
• Dyspepsia:
  • Chronic Episodic: 150 mg twice daily for up to 6 weeks.
  • Short-term Symptomatic Relief: 75 mg, repeated if necessary up to 4 doses daily.
  • Maximum Duration for Continuous Use: 2 weeks at one time.
• Erosive Esophagitis:
  • 150 mg four times daily.
  • Maintenance: 150 mg twice daily.
• NSAID-associated Ulceration:
  • Treatment: 150 mg twice daily or 300 mg at bedtime for 8-12 weeks.
  • Prevention: 150 mg twice daily.

Child Oral Dose (1 month to 16 years)

• Benign Gastric and Duodenal Ulceration:
  • 4-8 mg/kg daily in 2 divided doses.
  • Maximum: 300 mg/day.
  • Treatment Duration: 4-8 weeks.
  • Maintenance: 2-4 mg/kg once daily.
  • Maximum Maintenance: 150 mg/day.
• Gastroesophageal Reflux Disease (GERD):
  • 5-10 mg/kg daily in 2 divided doses.
  • Maximum: 300 mg/day.
• Erosive Esophagitis:
  • 5-10 mg/kg daily in 2 divided doses.
  • Maximum: 600 mg/day.

Renal Impairment

• Oral: If your creatinine clearance (CrCl) is less than 50 mL/min, the recommended dose is 150 mg once daily at bedtime. Dosage should be adjusted cautiously if necessary.
• Parenteral (IV): Individual doses may be reduced to 25 mg.

Hepatic Impairment

• No dosage adjustment is generally required for liver impairment.

Intravenous (IV) Administration

• Direct Injection: 50 mg diluted to approximately 20 mL with a compatible IV infusion fluid and administered over at least 5 minutes (4 mL/min).
• Intermittent Infusion: 50 mg added to approximately 100 mL of compatible IV solution and infused over 15-20 minutes.
• Continuous Infusion: 150 mg diluted in 250 mL of IV fluid and infused at a rate of 6.25 mg/hr for 24 hours.

Contraindications

• Porphyria (a group of rare genetic disorders that affect the nervous system or skin)

Precautions

• Exclusion of Malignancy: Before initiating treatment, particularly for gastric ulcers, your healthcare provider should rule out the possibility of underlying malignancy, as Zinetac may mask symptoms and delay diagnosis of gastric cancer.
• Swallowing Difficulties: Use with caution in patients who have difficulty swallowing.
• Kidney and Liver Impairment: Exercise caution and adjust the dose as needed in patients with impaired kidney or liver function.
• Pregnancy and Lactation: Use with caution during pregnancy. Ranitidine is known to cross into breast milk; therefore, discontinuation of the drug or careful consideration of alternatives is advised for breastfeeding mothers.

Interactions

• Propantheline bromide may delay Zinetac’s absorption and increase its peak plasma concentration.
• Ranitidine minimally inhibits the hepatic metabolism of certain drugs, including coumarin anticoagulants, theophylline, diazepam, and propranolol.
• It may alter the absorption of pH-dependent drugs (e.g., ketoconazole, midazolam, glipizide).
• Antacids may reduce the bioavailability of Zinetac.

Adverse Effects

• Common (1-10%): Headache (3%)
• Less Common (<1%): Abdominal pain, agitation, alopecia (hair loss), confusion, constipation, diarrhea, dizziness, hypersensitivity reactions, nausea, vomiting.
• Rare (Frequency Not Defined): Anemia, necrotizing enterocolitis (in fetus or newborn), pancreatitis, thrombocytopenia (low platelet count), pancytopenia (low count of all blood cell types), agranulocytosis (severe lack of white blood cells), acquired immune hemolytic anemia, arthralgia (joint pain), myalgia (muscle pain).
• Potentially Fatal: Anaphylaxis and severe hypersensitivity reactions.

Mechanism of Action

Ranitidine acts by competitively blocking histamine at the H2-receptors located on the gastric parietal cells. This action effectively inhibits gastric acid secretion. Importantly, it does not significantly affect pepsin secretion, pentagastrin-stimulated intrinsic factor secretion, or serum gastrin levels.

Note

Zinetac 150mg Tablet is manufactured by GlaxoSmithKline Pharmaceuticals Ltd., and its generic name is Ranitidine. Zinetac is available in Nepal. Please be advised that the information provided here, sourced from the Farmaco Nepal drug index, is not intended for diagnosis, medical advice, or treatment and should not be considered a substitute for professional medical judgment.