Lynparza Side Effects: What to Expect and When to Call Your Doctor

Starting Lynparza (olaparib) can feel daunting if you're not sure what side effects to expect. The good news: most patients tolerate Lynparza reasonably well, and many side effects are manageable with supportive care. That said, there are serious side effects that require immediate medical attention. This guide walks you through both.

Common Lynparza Side Effects (Occur in 10% or More of Patients)

These are the most frequently reported side effects from Lynparza clinical trials, primarily in ovarian cancer maintenance studies:

Nausea — The most common side effect. Mild to moderate nausea is very common, especially in the first few weeks. Taking Lynparza with food may help. Your doctor can prescribe antiemetics if needed.

Fatigue and asthenia (weakness) — Very common. Often improves with time. Rest when needed, and let your oncology team know if it's significantly affecting your daily life.

Anemia (low red blood cells) — Common and can worsen fatigue. Your blood counts are monitored regularly; dose adjustments or transfusions may be needed in some cases.

Vomiting — Related to nausea; antiemetics can help. Staying hydrated is important.

Diarrhea — Manageable with dietary adjustments. Avoid high-fiber and fatty foods during flares. Tell your doctor if it's severe or persists.

Decreased appetite — Eating smaller, frequent meals can help. A registered dietitian on your oncology team may have additional suggestions.

Headache and dizziness — Usually mild. Stay hydrated and avoid driving if you feel dizzy.

Dysgeusia (taste changes) — Food may taste different or metallic. This usually improves with time.

Cough and shortness of breath (dyspnea) — Mild respiratory symptoms are relatively common. Severe or worsening shortness of breath needs prompt evaluation (see serious side effects below).

Neutropenia, leukopenia, thrombocytopenia — Low white blood cells and platelets. Monitored with monthly blood counts; may require dose reduction.

Serious Side Effects: Call Your Doctor Immediately If You Notice These

1. Signs of MDS or Acute Myeloid Leukemia (AML)

Myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) occurred in approximately 1.2% of patients across Lynparza clinical studies. The majority of these cases were fatal. Warning signs include:

Unusual bruising or bleeding

Persistent or severe fatigue beyond your baseline

Frequent infections

Significant changes in blood count results (flagged by your regular monitoring)

This is why monthly blood count monitoring is mandatory. If MDS or AML is confirmed, Lynparza must be discontinued.

2. Pneumonitis (Lung Inflammation)

Lynparza can cause inflammation in the lungs (pneumonitis). Symptoms include:

New or worsening cough

Shortness of breath or difficulty breathing that is new or worsening

Fever

If pneumonitis is confirmed, Lynparza must be permanently discontinued. Call your doctor immediately—do not wait for your next scheduled appointment.

3. Venous Thromboembolism (Blood Clots)

Lynparza may cause blood clots in the veins (DVT) or lungs (pulmonary embolism). Seek emergency care immediately if you experience:

Sudden chest pain or pressure

Sudden shortness of breath

Swelling, redness, or pain in one leg (especially the calf)

Rapid heartbeat

4. Embryo-Fetal Toxicity

Lynparza can cause serious harm to an unborn baby. If you are a woman of childbearing potential, you must use effective contraception during treatment and for 6 months after your last dose. Male patients with female partners should use contraception during treatment and for 3 months after. Do not breastfeed during Lynparza treatment or for 1 month after the last dose.

What Monitoring Is Required While on Lynparza?

Complete blood count (CBC) at baseline and monthly throughout treatment

Report any new respiratory symptoms promptly

Pregnancy test before starting in women of reproductive potential

Getting Your Lynparza Prescription Filled

If you're managing side effects and also dealing with difficulty filling your prescription, medfinder can help locate a specialty pharmacy near you that has Lynparza in stock—so you can focus on your health, not pharmacy logistics.

See also: Lynparza Drug Interactions: What to Avoid and What to Tell Your Doctor.