Ranolazine

Summary

Ranolazine is a medication used to treat chest pain, especially in patients whose chest pain is unresponsive to other medications. Ranolazine works by inhibiting the late phase of the inward sodium current in myocardial cells, which reduces myocardial wall tension. This lowers the oxygen demand of the heart. Notably, ranolazine does not typically cause changes in the heart rate or blood pressure. Side effects of ranolazine include constipation, headache, dizziness, and nausea.

Key Points

• Ranolazine
  • Mechanism
    • Inhibits the late phase of inward sodium current
      • Inhibits late phase of sodium → reduced Na+ → reduced Na+/Ca+ exchange → reduced Ca+ inside cell → decreases diastolic wall tension and oxygen consumption
      • reduces diastolic wall tension
      • reduces myocardial oxygen demand
    • Does not affect heart rate or blood pressure
  • Clinical Use
    • Treats Angina
      • Used in angina not controlled by medication, stenting, or bypass surgery
  • Side Effects
    • Constipation
    • Dizziness
    • Headache
    • Nausea
    • QT prolongation
      • Rare finding caused by higher doses, where drug inhibits potassium repolarization current