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Osimertinib Side Effects

Medically reviewed by Philip Thornton, DipPharm. Last updated on Apr 30, 2022.


Commonly reported side effects of osimertinib include: cough. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to osimertinib: oral tablet

Side effects requiring immediate medical attention

Along with its needed effects, osimertinib may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking osimertinib:

More common

  • Anxiety
  • cough
  • dizziness, lightheadedness, or fainting
  • eye or vision changes
  • fast, pounding, or uneven heartbeat
  • pain in the chest, groin, or legs, especially the calves
  • pain, redness, or swelling in the arm or leg
  • slurred speech
  • sudden loss of coordination
  • sudden, severe headache
  • sudden, severe weakness or numbness in the arm or leg
  • trouble breathing

Less common

  • Blurred vision
  • chills
  • fever
  • general feeling of discomfort or illness
  • inability to speak
  • seizures
  • sneezing
  • sore throat
  • sudden, severe weakness on one side of the body
  • temporary blindness
  • thickening of bronchial secretions


Incidence not known

  • Blistering, peeling, loosening of the skin
  • diarrhea
  • itching
  • joint or muscle pain
  • red skin lesions, often with a purple center
  • sore throat
  • sores, ulcers, or white spots in the mouth or on the lips
  • unusual tiredness or weakness

Side effects not requiring immediate medical attention

Some side effects of osimertinib may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • Back pain
  • changes in the fingernails or toenails, including brittleness, inflammation, pain, redness, tenderness, separation from nail bed, or shedding of the nails
  • constipation
  • decreased appetite
  • headache
  • nausea
  • skin rash or dryness of the skin
  • swelling or inflammation of the mouth

For Healthcare Professionals

Applies to osimertinib: oral tablet


Very common (10% or more): Lymphopenia (63%), thrombocytopenia (54%), anemia (44%), neutropenia (33%)[Ref]


Very common (10% or more): Diarrhea (42%), nausea (17%), decreased appetite (16%), constipation (15%), stomatitis (12%), vomiting (11%)[Ref]


Very common (10% or more): Rash (e.g., generalized, erythematous, macular, maculopapular, papular, pustular), erythema, folliculitis, acne, dermatitis, acneiform dermatitis (58%), dry skin (e.g., eczema, skin fissures, xerosis) (36%), nail toxicity (e.g., nail and nail bed disorders, nail bed inflammation, nail bed tenderness, nail discoloration, nail dystrophy, nail infection, nail ridging, onychoclasis, onycholysis, onychomadesis, paronychia) (35%), pruritus (17%)

Postmarketing reports: Erythema Multiforme (EMM), Stevens-Johnson Syndrome (SJS), cutaneous vasculitis[Ref]


Very common (10% or more): Hyponatremia (26%), hypermagnesemia (20%)[Ref]


Very common (10% or more): Eye disorders (e.g., dry eye, blurred vision, keratitis, cataract, eye irritation, blepharitis, eye pain, increased lacrimation, vitreous floaters) (18%)

Uncommon (0.1% to 1%): Other ocular toxicities[Ref]


Very common (10% or more): Cough (17%), dyspnea (13%)

Common (1% to 10%): ILD/pneumonitis, pneumonia[Ref]


Very common (10% or more): Fatigue (22%)[Ref]


Very common (10% or more): Back pain (13%)[Ref]

Nervous system

Very common (10% or more): Headache (10%)

Common (1% to 10%): CVA/cerebral hemorrhage[Ref]


Common (1% to 10%): Cardiomyopathy, venous thromboembolism (includes deep vein thrombosis, jugular venous thrombosis, and pulmonary embolism)

Frequency not reported: QTc interval prolongation[Ref]

Frequently asked questions


1. "Product Information. Tagrisso (osimertinib)." Astra-Zeneca Pharmaceuticals (2015):

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.