Ranolazine also exhibits its effects on the delayed rectifier current (hERG/IKr potassium channels), it readily stimulates myogenesis, it reduces a pro-oxidant inflammation/oxidative condition, and activates the calcium signaling pathway.Ranolazine prolongs the action potential duration, with corresponding QT interval prolongation on electrocardiography, blocks the INa current, and prevents calcium overload caused by the hyperactive INa current, thus it stabilizes the membrane and reducing excitability. History
Syntex Inc. originally began developing ranolazine in 1985 and 61 studies were completed from then until 1994. Afterwards, Phase 2 studies were done however it was found that the formulation did not result in adequate plasma concentrations of drug. It is due to this that the sustained-release (SR) formulation of ranolazine was created.Roche acquired Syntex in 1994 In 1996, CV Therapeutics licensed the North American and European rights to ranolazine from Syntex, a subsidiary of Roche, which had discovered the drug and had developed it through Phase II trials in angina. In 2006, CV Therapeutics acquired the remaining worldwide rights to ranolazine from Roche. In 2008 CV Therapeutics exclusively licensed rights for ranolazine in Europe and some other countries to Menarini. In 2009, Gilead acquired CV Therapeutics. In 2013 Gilead expanded the partnership with Menarini to include additional countries, including those in Asia. Society and culture
Legal status
Ranolazine was approved by the FDA in January 2006, for the treatment of patients with chronic angina as a second-line treatment in addition to other drugs. In 2007 the label was updated to make ranolazine a first-line treatment, alone or with other drugs.
Side effects
The most common side effects are dizziness (11.5%) and constipation (10.9%). Other side effects include headache and nausea. Drug interactions
Ranolazine is metabolized mainly by the CYP3A enzyme. It also inhibits another metabolizing enzyme, cytochrome CYP2D6. For this reason, the doses of ranolazine and drugs that interact with those enzymes need to be adjusted when they are used by the same patient. Ranolazine should not be used with drugs such as ketoconazole, clarithromycin, and nelfinavir that strongly inhibit CYP3A, nor with drugs that activate CYP3A, such as rifampin and phenobarbital.For drugs that are moderate CYP3A inhibitors, such as diltiazem, verapamil, and erythromycin, the dose of ranolazine should be reduced.Drugs that are metabolized by CYP2D6, such as tricyclic antidepressants, may need to be given at reduced doses when administered with ranolazine. Mechanism of action
Ranolazine inhibits persistent or late inward sodium current (INa) in heart muscle in a variety of voltage-gated sodium channels. Inhibiting that current leads to reductions in intracellular calcium levels. This in turn leads to reduced tension in the heart wall, leading to reduced oxygen requirements for the muscle. The QT prolongation effect of ranolazine on the surface electrocardiogram is the result of inhibition of IKr, which prolongs the ventricular action potential.