Dasatinib Drug Interactions: What to Avoid and What to Tell Your Doctor

Dasatinib (Sprycel) has numerous drug interactions—some minor, some potentially serious. The drug is primarily metabolized by an enzyme in the liver called CYP3A4, which means that any medication that affects CYP3A4 activity can raise or lower dasatinib levels in your blood. Some medications and foods also affect how well dasatinib is absorbed. This guide covers the most important interactions you need to know about.

Always share a complete list of your medications with your oncologist and pharmacist before starting dasatinib, including prescription drugs, over-the-counter medications, vitamins, herbal supplements, and any complementary remedies.

Category 1: Strong CYP3A4 Inhibitors — Increase Dasatinib Levels

These medications block the CYP3A4 enzyme that breaks down dasatinib. When CYP3A4 is inhibited, dasatinib builds up in your blood to higher-than-intended levels, increasing the risk of side effects including bleeding, pleural effusion, and cardiac toxicity.

Strong CYP3A4 inhibitors to avoid or use with caution:

• Antifungals: ketoconazole, itraconazole, voriconazole, posaconazole
• Antibiotics: clarithromycin (Biaxin), telithromycin, troleandomycin
• HIV protease inhibitors: ritonavir, saquinavir, atazanavir, indinavir, nelfinavir, lopinavir
• Grapefruit juice (avoid entirely—even small amounts can significantly raise dasatinib levels)

If you must take one of these medications with dasatinib, your oncologist may need to reduce your dasatinib dose. Never start or stop these medications without consulting your oncologist.

Category 2: Strong CYP3A4 Inducers — Decrease Dasatinib Levels

These medications speed up CYP3A4 enzyme activity, causing dasatinib to be broken down faster—reducing its blood levels and potentially making it less effective at treating your leukemia.

Strong CYP3A4 inducers to avoid if possible:

• Rifampin (rifampicin) — a common antibiotic for tuberculosis and certain other infections
• Seizure medications: carbamazepine (Tegretol), phenytoin (Dilantin), phenobarbital
• Dexamethasone (a corticosteroid used in many cancer protocols)
• St. John's Wort — an herbal supplement commonly used for depression (avoid while taking dasatinib)

If coadministration with a strong CYP3A4 inducer cannot be avoided, your oncologist may consider increasing your dasatinib dose. Monitor treatment response closely during any change.

Category 3: Antacids, H2 Blockers, and Proton Pump Inhibitors (PPIs)

Dasatinib requires an acidic environment in the stomach to dissolve properly. Medications that reduce stomach acid can reduce dasatinib absorption and make it less effective.

• Antacids (Tums, Maalox, Rolaids): Take at least 2 hours before OR 2 hours after your dasatinib dose. Do not take simultaneously.
• H2 blockers (famotidine/Pepcid, cimetidine/Tagamet): Avoid — these significantly reduce dasatinib absorption. If you need acid suppression, use an antacid with the 2-hour separation instead.
• Proton pump inhibitors (PPIs) (omeprazole/Prilosec, lansoprazole/Prevacid, esomeprazole/Nexium): Avoid — PPIs cause prolonged stomach acid suppression that cannot be adequately timed around dasatinib. Alert your oncologist if you take a PPI regularly.

Category 4: Anticoagulants and Antiplatelet Drugs — Increased Bleeding Risk

Dasatinib can reduce platelet counts and impair platelet function. Combining it with blood-thinning medications significantly increases the risk of serious bleeding:

• Anticoagulants: warfarin (Coumadin), dabigatran (Pradaxa), rivaroxaban (Xarelto), apixaban (Eliquis), heparin
• Antiplatelet drugs: clopidogrel (Plavix), aspirin (except low-dose aspirin prescribed by your cardiologist)
• NSAIDs: ibuprofen (Advil, Motrin), naproxen (Aleve)

If your cardiologist has prescribed low-dose aspirin (81–162 mg) for heart disease prevention, discuss this specifically with your oncologist. Do not stop aspirin on your own, but don't start it either without consulting both doctors.

Category 5: QT-Prolonging Medications

Dasatinib can prolong the QT interval (an electrical measurement of heart rhythm). Combining it with other QT-prolonging drugs increases the risk of serious arrhythmia. Drugs in this category include certain antiarrhythmics (amiodarone, quinidine, sotalol), antipsychotics (haloperidol, ziprasidone), certain antibiotics (azithromycin, levofloxacin), and antiemetics (ondansetron at high doses). Ask your oncologist or pharmacist to review your full medication list for QT risk.

What to Do if You're Taking One of These Medications

Don't stop any existing medication without consulting your prescribing doctor. Instead, bring a complete medication list to your oncologist appointment before starting dasatinib. Your oncologist and pharmacist can review for interactions and adjust doses or timing as needed. For related safety information, see our guide on dasatinib side effects. If you need help finding your medication at a pharmacy, medfinder can help.