Lansoprazole

• Description: Lansoprazole is a proton pump inhibitor (PPI) that decreases the amount of acid produced in the stomach.
• Indication: It is used to treat and prevent stomach and duodenal ulcers, erosive esophagitis (damage to the esophagus from stomach acid), and other conditions involving excessive stomach acid such as Zollinger-Ellison syndrome. In this combination product, it primarily serves to reduce the risk of stomach ulcers that can be caused by the long-term use of aspirin.
• Mechanism of Action: Lansoprazole works by irreversibly blocking the proton pump (H+/K+ ATPase) in the gastric parietal cells. This pump is the final step in the production of stomach acid. By blocking it, lansoprazole effectively inhibits both basal and stimulated acid secretion.

Aspirin

• Description: Aspirin is a nonsteroidal anti-inflammatory drug (NSAID) and an antiplatelet agent.
• Indication: It is used to reduce pain, fever, and inflammation. In the context of a combination drug with a PPI, it is primarily used for cardiovascular benefits, such as preventing heart attacks and strokes in high-risk patients.
• Mechanism of Action: Aspirin’s antiplatelet effect is due to its irreversible inhibition of the cyclooxygenase (COX-1) enzyme in platelets. This enzyme is responsible for producing thromboxane A2, a molecule that promotes platelet aggregation and blood clot formation. By inhibiting this process, aspirin reduces the risk of blood clots. Its analgesic and anti-inflammatory effects are also related to COX inhibition, but in this case, it inhibits both COX-1 and COX-2 enzymes.