Niraparib belongs to the class of cancer-fighting medications called antineoplastics.

It is used in the treatment of advanced or recurrent ovarian, fallopian tube, or peritoneal cancer. Niraparib works by interfering with the reproduction of cancer cells. This kills existing cancer cells and prevents new tumour cell growth.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The recommended dose of niraparib varies depending on your body weight and your platelet count, as well as whether you have received other treatments. Your doctor will determine the correct dose for you. Doses usually range between 200 mg and 300 mg taken once daily.

Swallow the capsules whole, with something to drink. Do not crush, chew, or open the capsules. It may be taken with food or on an empty stomach.

This medication works best if it is taken at approximately the same time each day. If it causes nausea, taking it at bedtime may help.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor. If you vomit after taking a dose, do not take another dose. Continue with your regular dose the next day.

If you miss a dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Capsule

Each hard gelatin capsule with a white body and purple cap, imprinted "100 mg" in black ink on the body and "Niraparib" printed in white ink on the cap, contains 100 mg of niraparib as niraparib tosylate. Nonmedicinal ingredients: FD&C Blue No. 1, FD&C Red No. 3, FD&C Yellow No. 5 (tartrazine), gelatin, lactose, magnesium stearate, pharmaceutical grade printing ink, and titanium dioxide.

Tablet

Each immediate-release, grey, oval, film-coated tablet, debossed with "100" on one side and "Zejula" on the other side, contains 100 mg of niraparib as niraparib tosylate. Nonmedicinal ingredients: crospovidone, ferrosoferric oxide, lactose monohydrate, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polyvinyl alcohol, povidone, silicon dioxide, talc, and titanium dioxide.

Do not take this medication if you:

• are allergic to niraparib or any ingredients of the medication
• are breast-feeding

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• anxiety
• constipation
• cough
• diarrhea (3 or more loose bowel movements in a day)
• dizziness
• dry mouth
• eye, nose, mouth, or throat irritation
• eye infection
• headache
• heartburn or indigestion
• hot flashes
• joint, muscle, or back pain
• loss of appetite
• memory problems
• mouth sores
• nausea
• sensitivity to sunlight
• skin rash
• stomach pain
• taste changes
• tiredness
• trouble sleeping
• vomiting
• weakness
• weight loss

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• chest pain or pressure
• confusion, impaired memory or thinking
• fast or pounding heartbeat
• high blood pressure (shortness of breath, fatigue, dizziness, or fainting)
• rash
• shortness of breath
• signs of anemia (low red blood cells; e.g., dizziness, pale skin, unusual tiredness or weakness, shortness of breath)
• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don't stop bleeding)
• signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
• signs of infection (symptoms may include fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness)
• signs of kidney problems (e.g., increased urination at night, decreased urine production, blood in the urine)
• swelling of the legs and ankles
• symptoms of lung inflammation (e.g., cough, shortness of breath, trouble breathing)
• symptoms of a urinary tract infection (e.g., pain when urinating, urinating more often than usual, low back or flank pain)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• hallucinations
• signs of bone marrow disease (e.g., fever, infection, bruising or bleeding, shortness of breath, blood in the urine or stool)
• signs of a rare neurological disorder called posterior reversible encephalopathy syndrome (PRES; e.g., confusion, dizziness, headache, high blood pressure, seizures, vision problems, or blindness)
• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• sudden, extreme increase in blood pressure

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Blood counts: This medication can decrease the number of neutrophils (a type of white blood cell that helps fight infection), red blood cells (which carry oxygen), and platelets (which help your blood to clot). Your doctor will do blood tests to monitor this. If you notice any signs of infection (e.g., fever, chills, or sore throat) or unusual bleeding or bruising, contact your doctor immediately.

Blood pressure and heart rate: Niraparib can cause increased blood pressure and heart rate.  If you have high blood pressure, or other heart conditions, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Cancer: Although uncommon, people taking niraparib have developed myelodysplastic syndrome/acute myeloid leukemia (MDS/AML), a type of cancer in which blood cells do not mature in the bone marrow and do not become healthy blood cells. This may be related to niraparib and it may also be related to previous chemotherapy and radiation. Talk to your doctor if you have concerns.

Driving and operating machinery: Niraparib can cause drowsiness or dizziness, affecting the mental or physical abilities needed to drive or operate machinery. Avoid driving, operating machinery, or performing other potentially hazardous tasks until you have determined how this medication affects you.

Posterior Reversible Encephalopathy Syndrome (PRES):  This is a rare condition of the brain where the covering that protects the nerves is destroyed, affecting how the nerves in the brain transmit messages. Signs and symptoms of leukoencephalopathy include unusual clumsiness, gradually worsening weakness, visual, speech or personality changes, or possibly seizures. If you experience any of these, contact your doctor immediately.

Sensitivity to sunlight: This medication may increase the sensitivity of the skin to sunlight, increasing the risk of sunburn. Avoid exposure to sunlight for long periods of time, particularly between the hours of 10 am and 2 pm. Wear a broad-spectrum sunscreen and lip balm with an SPF of 30 or greater. If you notice any unusual skin rash or peeling, contact your doctor immediately.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. People who may become pregnant must use effective birth control while taking niraparib and for at least 6 months after taking the last dose. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if niraparib passes into breast milk. If you are breast-feeding and taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children.

For a full list of interactions, use the Drug Interaction Checker available on the Drugs.com website.

If you are taking other medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.