Medication Name and Classification

Zantac, also known generically as ranitidine, is classified as an H2 (histamine-2) receptor antagonist. It works by reducing the amount of acid the stomach produces, thereby providing relief from conditions caused by excess stomach acid.

Therapeutic Indications

Zantac is indicated for the treatment of gastroesophageal reflux disease (GERD), peptic ulcer disease, and Zollinger-Ellison syndrome. It is also used to prevent stress ulcers and to treat conditions in which the stomach produces too much acid.

Dosage Forms Available

Zantac is available in multiple dosage forms including tablets, effervescent tablets, and oral solution. The tablets come in strengths of 75 mg, 150 mg, and 300 mg. The oral solution is available in strengths of 150mg/10mL.

Proper Administration Techniques

Zantac should be taken exactly as prescribed by a healthcare provider. Oral tablets should be swallowed whole, not chewed, crushed, or broken. The effervescent tablets should be dissolved in a glass of water before ingestion. Measure liquid forms with a proper dose-measuring device.

Typical Dosing Recommendation

For active duodenal ulcers, the typical adult dose is 150 mg twice daily or 300 mg once daily after the evening meal or bedtime. For GERD, the usual dose is 150 mg twice daily. For maintenance therapy, a dose of 150 mg at bedtime is recommended. Pediatric dosing is determined based on body weight and the specific condition being treated.

Mechanism of Action

Zantac, by inhibiting the action of histamine on H2 receptors of the parietal cells in the stomach, decreases gastric acid secretion and concentration. This helps to alleviate symptoms and promote healing in acid-related conditions.

Drug Interactions

Zantac may interact with certain drugs such as warfarin, where it could potentially alter its effect. The absorption of ketoconazole and atazanavir can be reduced when administered concurrently with Zantac. Smoking decreases the effectiveness of Zantac, thus patients should be advised to quit smoking.

Known Contraindications

Zantac is contraindicated in patients with a known hypersensitivity to ranitidine or any of the excipients. It is also contraindicated in patients with a history of acute porphyria, as it has been linked to exacerbation of this condition. It should not be used in those with severe renal or liver impairment without proper medical supervision.

Adverse Reactions

Common adverse reactions include headache, constipation, or diarrhea. Less commonly, dizziness, insomnia, or nausea may occur. Rarely, Zantac can lead to more severe conditions such as liver enzyme abnormalities or acute pancreatitis. Long-term use has been associated with vitamin B12 deficiency due to decreased stomach acid.

Monitoring Parameters

Patients on long-term therapy should have their liver function monitored periodically. Renal function tests are also recommended, especially in elderly patients. Monitoring for signs of gastrointestinal bleeding or perforation is essential in patients with severe gastrointestinal disorders.

Storage Instructions

Zantac tablets should be stored at room temperature, away from light and moisture. The oral solution should be stored under the same conditions and discarded after the expiration date. Always keep medications out of the reach of children.

Special Populations

Pregnant women should use Zantac only if clearly needed and after consulting with a healthcare provider, as there is limited data on its safety during pregnancy. Nursing mothers should also exercise caution. Dose adjustments may be necessary for elderly patients due to the increased likelihood of renal impairment.

Patient Counseling Information

Patients should be advised to take the medication as directed, even if they feel better before completing the prescribed course. They should be instructed to report any signs of unusual bleeding, yellowing of the skin or eyes, or severe abdominal pain to their healthcare provider immediately. Lifestyle modifications, such as dietary changes and weight loss, may be recommended to complement the treatment of acid-related conditions.