Zantac (Ranitidine) and Omeprazole both are prescribed to treat Peptic Ulcers, Gastroesophageal Reflux Disease (GERD) and dyspepsia although with different mode of actions and with different targets. However the main motto for using the both of them remains same i.e. reduction of gastric acid. A peptic ulcer is erosion in the lining of the stomach or the first part of the small intestine, an area called the duodenum. If the peptic ulcer is located in the stomach it is called a gastric ulcer. Gastroesophageal reflux disease (GERD) is a condition in which the stomach contents (food or liquid) leak backwards from the stomach into the esophagus (the tube from the mouth to the stomach). Both Zantac and Omeprazole are helpful in these conditions by inhibiting the gastric acid production.
Zantac (Generic Name Ranitidine) is an antagonist for H2 receptor of Histamine receptors on the parietal Cells of the stomach, which results in the decrease in the production the acid from these cells. It was first introduced in the market in 1981 and was the first H2 receptor antagonist. Besides Peptic Ulcers, Gastroesophageal Reflux Disease (GERD) and dyspepsia, it is also used as antiemetic in the preoperative cases and given prior to chemotherapy as premedication for its antiemetic effects. It is also used to treat pediatric reflux, where it is preferred over Omeprazole and other Proton Pump Inhibitors, because it does not induce histologically relevant hyperplastic changes in the parietal cells. Usual dose of ranitidine is 150 mg twice a day.
Omeprazole belongs to the class of the drugs Proton Pump Inhibitors. It was first introduced in the market in 1989 by Astra Zeneca and since then it has taken over the role of Ranitidine in the treatment of Peptic Ulcers, Gastroesophageal Reflux Disease (GERD). This class of drugs works by suppression of the hydrogen/potassium adenosine triphosphatase enzyme system i.e. H+/K+ ATPase or commonly known as Proton Pump. Proton Pump is responsible for the secretion of H+ ions in the gastric lumen thus increasing the acidity of the lumen. By inhibiting the action of proton pump it regulates acid production directly. Due to lack of acid in stomach and duodenum the ulcers heal faster. Omeprazole is given in inactive form. This inactive form is a lipophilic by nature and neutrally charged and can cross the cell membranes easily. In acidic environment of the parietal cells it gets protonated and turns into active form. This active for binds to the Proton pump covalently and inactivates it. Thus resulting in the suppression of gastric acid secretion.
Difference between Zantac and Omeprazole
As discussed above both the drugs are similar in the prescription and had a bit common motto behind the use i.e. the suppression of gastric acid secretion. However pharmacologically both drugs have different mode of actions as Zantac acts on the H2 receptors while Omeprazole acts on the Proton Pump directly. In the treatment of Gastric and Peptic Ulcers the Omeprazole is preferred nowadays due to more effective and long lasting acid secretion inhibition. However the Zantac is still used for its antiemetic properties as prophylactic drug. It can also be given as a concomitant medication with NSAIDS to reduce the chances of acidity. Long term use of Omeprazole can lead to vitamine B12 deficiency as Omeprazole hinders its absorption by reducing the acidic environment.
Many Clinical Trials are done to compare these two drugs and results are more or less similar from all of them. compared with ranitidine, omeprazole provides faster relief of symptoms but no improvement in long-term success of intermittent treatment for GERD and Peptic Ulcers. Omeprazole should be preferred if the rapid reduction of the symptoms is necessary however It is not superior to Zantac for long term use.