How does PARP inhibitor therapy work?

Cells constantly repair damage to their DNA. PARP proteins help repair particular types of breaks. When a medicine blocks PARP, damage can build up. Cancer cells that already have difficulty repairing DNA, including some with changes affecting BRCA-related repair, may be especially vulnerable. This treatment approach is sometimes used for [Ovarian Cancer](/conditions/ovarian-cancer/), [Pancreatic Cancer](/conditions/pancreatic-cancer/) or selected breast cancers. The medicine may be taken as tablets or capsules, according to the prescribed schedule.

Take each dose exactly as directed and tell your oncology team about all medicines, supplements and health conditions. Do not alter the dose for nausea or tiredness without advice. Your team may arrange blood tests to check blood-cell levels and organ function. Keep a record of symptoms such as fatigue, nausea, reduced appetite or unusual bruising. Ask whether genetic or tumour testing is needed to assess whether a [PARP Inhibitor Drug](/materials/parp-inhibitor-drugs/) is suitable.

Call your treatment team urgently for fever, chills, breathlessness, chest discomfort, heavy bleeding, black stools or sudden marked weakness. These symptoms can signal infection, anaemia or another complication requiring assessment. Report persistent vomiting or diarrhoea because dehydration can affect your ability to continue treatment.

Ask why this medicine is being recommended, how long treatment may continue, which blood tests are planned, and what to do after a missed dose. Discuss pregnancy prevention, fertility concerns and how this therapy fits with surgery, chemotherapy or other medicines.