Nausea, vomiting, loss of appetite, constipation, bad taste in your mouth, dry mouth, mouth sores, dizziness, headache, or trouble sleeping may occur. Rarely, nausea and vomiting can be severe. Taking this medication at bedtime may help reduce nausea. In some cases, your doctor may prescribe medication to prevent or relieve nausea and vomiting. Eating several small meals or limiting activity may help lessen nausea and vomiting. If any of these effects last or get worse, tell your doctor or pharmacist promptly.
People using this medication may have serious side effects. However, you have been prescribed this drug because your doctor has judged that the benefit to you is greater than the risk of side effects. Careful monitoring by your doctor may decrease your risk.
This medication decreases bone marrow function, an effect that may lead to a low number of blood cells such as red cells, white cells, and platelets. This effect can cause anemia, decrease your body's ability to fight an infection, or cause easy bruising/bleeding. Rarely, this medication may also cause certain cancers of the bone marrow or blood cells. Your doctor will monitor your blood cell count. Tell your doctor right away if you develop any of the following symptoms: signs of anemia (such as unusual tiredness, pale skin, shortness of breath, fast heartbeat), signs of infection (such as sore throat that doesn't go away, fever, chills, cough), easy bruising/bleeding (such as pink/bloody urine, black/bloody stools), weakness, weight loss.
Tell your doctor right away if you have any serious side effects, including: signs of kidney problems (such as change in the amount of urine).
Rarely, niraparib may cause a condition called PRES (posterior reversible encephalopathy syndrome). Get medical help right away if you develop a headache that doesn't go away, seizures, sudden vision changes, mental/mood changes (such as confusion).
This medication may raise your blood pressure and heart rate. Sometimes these effects can be serious. Check your blood pressure and heart rate regularly and tell your doctor if the results are high. Your doctor may control your blood pressure and heart rate with medication.
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.