Ranolazine
1 medicine
Ranolazine treats chronic angina by helping the heart work more efficiently; it prolongs the QT interval and interacts seriously with CYP3A4 inhibitors and inducers.
Key facts
- Ranolazine (sold as Ranexa) is an anti-anginal medicine that reduces chest pain from chronic angina without significantly changing heart rate or blood pressure.
- You take it as a slow-release tablet, usually twice daily, swallowed whole; it is used long-term for prevention, not for an acute angina attack.
- Ranolazine prolongs the QT interval, an electrical measurement of the heartbeat, and dangerous heart rhythms can result if it is combined with strong CYP3A4 inhibitors, such as ketoconazole, clarithromycin, or ritonavir, or with other QT-prolonging medicines.
- Seek urgent care for fainting, a fast or irregular heartbeat, or palpitations that feel different from usual.
What ranolazine treats
Ranolazine treats chronic stable angina, recurring chest pain caused by reduced blood flow to the heart muscle during exertion. It is used alongside other angina medicines, such as beta-blockers or calcium channel blockers, when symptoms persist despite those treatments. It does not relieve a sudden angina attack and is not a rescue medicine.
How ranolazine works
During angina, heart muscle cells become overloaded with sodium and calcium, which stiffens the heart and increases its oxygen demand. Ranolazine blocks a late sodium current in heart cells, reducing this overload so the heart muscle relaxes more easily and needs less oxygen, without significantly slowing the heart rate or lowering blood pressure.
Before you take it
- Tell your prescriber about liver disease, since ranolazine is not recommended with significant liver impairment.
- Mention any medicines that strongly affect the CYP3A4 enzyme, including certain antifungals, HIV protease inhibitors, some antibiotics, and rifampin, since these change ranolazine levels significantly.
- Tell your prescriber about any history of QT prolongation, an irregular heartbeat, or other QT-prolonging medicines you take.
- Avoid grapefruit juice, which raises ranolazine levels.
Side effects
Common effects include dizziness, headache, constipation, nausea, and mild weakness.
Stop and seek urgent medical care for any of these:
- Fainting, or a fast, irregular, or pounding heartbeat.
- Sudden dizziness with confusion.
- Signs of an allergic reaction: rash, facial swelling, or difficulty breathing.
- Reduced urine output or swelling suggesting kidney problems.
Safety essentials
- Ranolazine prolongs the QT interval; do not combine it with other QT-prolonging medicines or strong CYP3A4 inhibitors, since together they can trigger a dangerous heart rhythm.
- Strong CYP3A4 inducers, such as rifampin, can lower ranolazine levels enough to make it ineffective; avoid this combination too.
- Have your prescriber review all new medicines, including over-the-counter and herbal products, before you start them, because of how many drugs interact with ranolazine's metabolism.
This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.