Paclitaxel may rarely cause serious (rarely fatal) allergic reactions. Patients who experience a severe allergic reaction with this drug must never use it again. Your doctor may prescribe other medications (such as antihistamines, corticosteroids) to help prevent an allergic reaction. However, severe allergic reactions may still occur in a few patients. Get medical help right away if you develop any signs of an allergic reaction such as rash, itching, swelling, severe dizziness, trouble breathing, or chest pain.

This medication may often cause a serious blood disorder (decreased bone marrow function leading to a low number of white blood cells). This effect can lower your body's ability to fight an infection. Your doctor will monitor you closely and check your blood often during treatment. If your white blood cell count is too low, you should not receive this medication. Tell your doctor right away if you develop any signs of infection (such as sore throat that doesn't go away, fever, chills, cough, painful/difficult urination).