Osimertinib
What osimertinib is used for
Osimertinib, marketed as Tagrisso, is an oral targeted cancer medicine that inhibits particular epidermal growth factor receptor (EGFR) mutations. Its US indications concern defined EGFR-mutated non-small cell lung cancers, including treatment after surgery, certain unresectable stage III cancers after chemoradiation, and specific advanced or metastatic settings. Some indications use it alone and another uses it with chemotherapy. Eligibility depends on mutation testing, cancer stage and prior treatment; a medicine name alone cannot identify a suitable treatment.
Form and treatment monitoring
This profile concerns the oral tablets containing osimertinib, rather than an interchangeable class of all EGFR inhibitors. The oncology team determines the regimen and monitoring. Blood counts are checked before treatment and during follow-up. Electrocardiograms and electrolyte measurements are important when there are cardiac risks or other medicines that affect the QT interval. Heart-pumping function may also need assessment. Do not change a cancer medicine or its dose because of an online interaction entry.
Important interaction differences
Strong CYP3A enzyme inducers, such as rifampicin, carbamazepine and phenytoin, can substantially lower osimertinib exposure and reduce effectiveness; the US label recommends avoiding these combinations. This is not the same as an interaction with every CYP3A medicine. In the label studies, itraconazole did not cause a clinically significant change in osimertinib exposure, and omeprazole did not materially affect exposure. Osimertinib can increase exposure to some transporter substrates, including rosuvastatin and fexofenadine. Other medicines that prolong QT require a specific cardiac review.
Common effects and urgent symptoms
Diarrhoea, rash, dry skin, nail changes, mouth inflammation, fatigue and changes in blood counts are common in relevant treatment groups. A new or worsening cough, fever or breathlessness needs urgent assessment because lung inflammation can be serious. Fainting, marked palpitations or symptoms of heart failure also need prompt attention. Severe blistering or peeling skin, unusual bruising or infections, and new eye pain or visual changes should be reported without waiting for a routine appointment. The September 2026 label update also addresses muscle pain or inflammation with elevated creatine phosphokinase; unexplained muscle pain or tenderness should be reported.
Pregnancy, breastfeeding and sources
Osimertinib can harm an unborn baby. The label gives contraception requirements for patients who could become pregnant and for male patients with partners who could become pregnant; these should be discussed with the treatment team. Breastfeeding is not recommended during treatment or for two weeks after the last dose. This source-based summary was checked against the current DailyMed Tagrisso label, SPL version 37, effective 14 September 2026. It is educational information, not a substitute for the full product information or an individual oncology review.