Pathways

Cilostazol, industrially sold as Pletal, is a quinolone derivative antiplatelet drug and a vasodilator used to prevent platelet aggregation, specifically treating symptoms of intermittent claudication caused by peripheral artery disease as well as preventing strokes in Homo sapiens. It acts on blood cells called platelets and on the vasculature by inhibiting phosphodiesterase 3 activity which causes these platelets to stop from sticking together, preventing formation of harmful clots. Cilostazol helps the blood to move more easily and keeps blood flowing smoothly in your body. Cilostazol is ingested orally, and it enters the liver (not shown here), where it is metabolized into active metabolites that inhibit the action of cAMP-specific 3',5'-cyclic phosphodiesterase 4D which converts cyclic adenosine monophosphate (cAMP) to adenosine monophosphate (AMP) in platelets. Inhibition of PDE3 causes a build-up of cAMP which subsequently leads to increased concentrations of the active form of protein kinase A (PKA). PKA then converts vasodilator-stimulated phosphoprotein (VASP) into phosphorylated vasodilator-stimulated phosphoprotein (VASP-P) which in turn is known to prevent aggregation of platelets, by inhibiting their adhesion to collagen, as well as decreasing the amount of calcium within the cytosol, preventing granule release, which then prevents activation of other platelets. Usage of cilostazol relieves symptoms like claudication(cramps) and the intermittent pain it causes. Common side effects of cilostazol are headache, diarrhea, vomiting, abnormal stools, dizziness, weakness, fast or pounding heartbeats, palpitations, swelling (edema), leg cramps, numbness or tingling, joint pain, cough, runny or stuffy nose, infections.

Metabolites of Cilostazol are predicted with biotransformer.

Cimetidine, sold as Tagamet, is a compound related to histamine. It is a H2 antagonist drug, also called H2RAs or H2 blockers, and was the first of this class to be discovered. H2 antagonist drugs compete with histamine to bind to the histamine H2-receptors found on the basolateral membrane of gastric parietal cells. This blocks histamine effects, resulting in reduced gastric acid secretion and a reduction in gastric volume and acidity. Cimetidine also helps to block pepsin and gastrin output, and due to the inhibition of gastric acid secretion, it is typically used to treat heartburn and ulcers. Cimetidine also blocks the activity of cytochrome P-450 enzymes CYP1A2, 2C9, 2C19, 2D6, 2E1 and 3A4, which may affect the metabolism of other drugs.

Cimetidine is an H2 receptor antagonist drug that is mainly used to treat peptic ulcers and heartburns. It works by acting as a competitive inhibitor and blocks the action of histamine on Histamine H2 receptors. This ultimately reduces gastric acid secretion in the stomach lumen by parietal cells that is caused by histamines interaction with the H2 receptor. This receptors activation causes downstream cascading signals that target the transporters pumping out hydrogen ions which leads to the secretion of acid in the stomach lumen.

Cimetidine, an H2 receptor antagonist drug mainly used to treat peptic ulcers and heartburns, is absorbed through the cells that line the small intestine into portal circulation. After it enters the liver hepatocyte from portal circulation, Cimetidine is metabolized by flavin containing monooxygenases and other P450 enzymes into cimetidine sulfoxide and hydroxymethyl cimetidine. These metabolites then enter systemic circulation. Research is still being conducted to find the specific types of enzymes that are involved in the metabolism of the drug into these metabolites.

Cimetidine, sold as Tagamet, is a compound related to histamine. It is a H2 antagonist drug, also called H2RAs or H2 blockers, and was the first of this class to be discovered. H2 antagonist drugs compete with histamine to bind to the histamine H2-receptors found on the basolateral membrane of gastric parietal cells. This blocks histamine effects, resulting in reduced gastric acid secretion and a reduction in gastric volume and acidity. Cimetidine also helps to block pepsin and gastrin output, and due to the inhibition of gastric acid secretion, it is typically used to treat heartburn and ulcers. Cimetidine also blocks the activity of cytochrome P-450 enzymes CYP1A2, 2C9, 2C19, 2D6, 2E1 and 3A4, which may affect the metabolism of other drugs.