Key takeaways:
Tagrisso (osimertinib) is a targeted therapy medication. It’s an oral tablet that treats certain types of non-small cell lung cancer.
Tagrisso can cause side effects such as low blood cell counts, diarrhea, and nail changes. Many side effects tend to get better as your body adjusts to the medication.
Mild Tagrisso side effects can be managed at home. But more serious risks, including skin reactions and lung problems, warrant prompt medical attention. Your oncologist can tell you more about how to manage Tagrisso side effects.
Genetic mutations are the culprit behind many cases of non-small cell lung cancer (NSCLC). They encourage cancer cells to grow and spread, but modern technology is making them less threatening. Cancer specialists can run DNA tests to determine which mutations are causing cancer cells to grow. And countless mutation-targeting medications are now available.
Tagrisso (osimertinib) is one popular option. It’s a targeted therapy medication that treats NSCLC that’s epidermal growth factor receptor (EGFR) mutation-positive. By targeting and blocking EGFR, Tagrisso helps slow lung cancer cell growth.
There are some downsides, though. Even though it's not a traditional chemotherapy medication, this oral tablet can cause some significant side effects. Many side effects are manageable and get better with time. However, serious side effects may require medical attention.
Tagrisso side effects at a glance
Like all medications, Tagrisso can cause side effects.
Common Tagrisso side effects include:
Low blood cell counts
Low platelets
Diarrhea
Joint pain
Muscle pain
Dry skin
Fatigue
Nail changes
Mouth sores
Skin rashes
Bruising and bleeding
Infection
Nausea
Constipation
Cough
Rare but serious Tagrisso risks include:
Lung inflammation
Heart rhythm problems
Heart failure
Serious skin reactions
Eye problems
Immune system reactions
Blood disorders, including aplastic anemia
Severe allergic reactions
Here’s how to manage 12 noteworthy Tagrisso side effects.
1. Changes in blood cell counts
Tagrisso may lead to a drop in your white blood cells, platelets, and red blood cells. The impact of this varies depending on which blood cells are affected — and how low they go.
When your white blood cells are lower than normal, your immune system becomes weaker. This leads to a higher risk of catching an infection. When your platelets or red blood cells are lower than normal, there’s a higher risk of bleeding and bruising.
Let your oncologist know if you develop any new symptoms of an infection, such as fever, chills, or cough, while you’re receiving Tagrisso. Also, let them know if you experience unusual bruising or bleeding that doesn’t stop or go away. This could include blood in your urine or stool, bleeding gums, or reddish-purple dots on your skin.
Tagrisso logistics: Discover how Tagrisso works to fight certain types of non-small cell lung cancer and how it compares to other lung cancer medications.
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Risks like these highlight the importance of routine lab work. Your oncologist should check your blood work before starting treatment with Tagrisso. They’ll likely do this regularly throughout your treatment, too. If your blood cell counts become too low, your oncologist may suggest lowering your dose of Tagrisso or stopping it altogether.
2. Diarrhea
Diarrhea is another common Tagrisso side effect. Nearly half of people who took Tagrisso in clinical studies reported experiencing it. Diarrhea is generally more common in the first month of taking Tagrisso, but it should improve over time.
If you develop diarrhea, it’s important to stay hydrated. Drinking 8 to 10 glasses of non-sugary liquids a day is a good starting point, but make sure to listen to your oncologist’s instructions if they want you to aim for a different quantity.
It also helps to avoid spicy and greasy foods that may make diarrhea worse. When needed, you can consider an over-the-counter (OTC) antidiarrheal medication, such as loperamide (Imodium A-D), with your oncologist’s OK.
3. Joint or muscle pain
Another common side effect of Tagrisso is muscle and joint pain. About one-third of people who took Tagrisso in clinical trials reported one or both issues.
To combat muscle and joint pain, try keeping up with regular exercise. This helps promote muscle and bone strength. Even light exercise, as your body can tolerate it, can make a difference. Some people find relief with alternative therapies, like massages, too. OTC pain relievers, such as acetaminophen (Tylenol) or naproxen (Aleve), can help relieve pain when needed.
4. Dry skin
Tagrisso can sometimes cause your skin to become dry and itchy. Dry skin tends to show up after taking Tagrisso for 5 weeks or longer.
If your skin dries out while taking Tagrisso, sticking to a skincare routine can help. You can apply moisturizing creams or lotions that are fragrance-free and non-irritating to your skin a couple of times per day. Products containing urea or colloidal oatmeal are especially helpful.
If your dry skin feels intense, loop in your oncologist. They may recommend a prescription corticosteroid cream, such as triamcinolone. They may also want you to pause treatment with Tagrisso and restart it at a lower dose once your dry skin has improved.
5. Nail changes
Tagrisso may cause changes to your fingernails or toenails. This includes nail tenderness, brittleness, or separation from the nailbed. If they happen, they tend to appear after taking the medication for 6 to 8 weeks.
Some ways to help prevent and manage nail changes include:
Cutting your nails short and keeping them clean
Applying nail polish to protect your nails
Avoiding wearing tight shoes
Wearing gloves while working, gardening, or cleaning
Taking a biotin supplement to help strengthen nails over time
If nail changes become severe, reach out to your oncologist. They may recommend removing the affected nails so they can regrow.
6. Mouth sores
Tagrisso can cause mouth inflammation, potentially leading to mouth sores. Symptoms range from mouth tingling and cracks in the side of the mouth to painful ulcers. They often make eating and drinking more difficult, too.
Prevention is key when it comes to mouth sores. Minimizing their impact can make a meaningful difference in your quality of life. These are some tips to manage mouth sores:
Brush your teeth with a soft toothbrush.
Avoid alcohol or mouthwashes that contain alcohol.
Rinse your mouth several times a day with salt water and baking soda.
Suck (don’t chew) on ice chips.
Avoid eating crunchy or hard foods that may cut the inside of the mouth.
If mouth sores become unmanageable, contact your oncologist. They may be able to recommend other medications for mouth pain and inflammation, such as magic mouthwash or viscous lidocaine.
7. Skin rashes
Tagrisso can cause an acne-like rash on the face, scalp, and/or torso. Rashes tend to appear within the first 2 weeks of taking Tagrisso, but they generally get better over time.
To manage rashes from Tagrisso, you should loop in your oncologist once you first notice any rashes. Prescription medications, such as minocycline (Minocin) pills or hydrocortisone (Locoid) cream, can help keep it under wraps. If the rash is severe, they may recommend pausing your Tagrisso regimen or lowering your Tagrisso dosage.
Although rare, serious skin reactions have also been reported — including cases of Stevens-Johnson syndrome. Go to the nearest ER if you develop a fast-spreading rash, skin peeling, or fluid-filled blisters.
Good to know: Some skin rashes from Tagrisso may look like acne. However, they’re not acne. Acne products shouldn’t be used to treat skin changes from Tagrisso.
8. Lung inflammation
Tagrisso can very rarely cause a serious lung problem called interstitial lung disease (ILD). This can be dangerous if left untreated. ILD can cause lung scarring and make it hard to breathe.
Let your oncologist know right away if you suddenly experience a fever, cough, or shortness of breath. If your symptoms feel especially severe, go to the nearest ER.
9. Heart rhythm problems
Tagrisso can contribute to a heart rhythm problem known as QT prolongation. This is when the heart takes a while to reset between beats. Possible symptoms include chest fluttering (palpitations), lightheadedness, and feeling faint. Your risk for this is higher if you have a history of heart rhythm problems or take other medications that also cause QT prolongation.
It’s important to get ahead of QT prolongation before it happens. If you have a history of heart problems, your care team may periodically monitor your heart rhythm with a test called an electrocardiogram.
10. Eye problems
Although rare, Tagrisso can cause eye problems such as keratitis (eye inflammation). Keratitis can lead to eye pain, redness, and sensitivity to light. It can also cause watery eyes and blurry vision.
Let your oncologist know if you start experiencing any eye discomfort after starting Tagrisso. If your symptoms are mild, such as some dryness or irritation, they may recommend an OTC eye drop for relief. But if they think your symptoms are more substantial, they may refer you to an eye specialist to evaluate the issue further.
Depending on the severity of the inflammation, your oncologist may recommend lowering your Tagrisso dosage or stopping it temporarily.
11. Immune system reactions
Tagrisso can cause immune system reactions that affect the skin, lungs, or small blood vessels. Inflammation of the small blood vessels, called cutaneous vasculitis, can cause red or purple spots on the skin, hives that appear bruised, or a long-lasting rash.
Let your oncologist know right away if you experience any unusual skin changes while taking Tagrisso. If your oncologist suspects you have developed vasculitis, they may have you stop taking Tagrisso temporarily. If it's severe, you may need to stop taking it altogether.
12. Serious blood disorders
Tagrisso can cause a rare blood disorder called aplastic anemia. It’s a serious condition that prevents your bone marrow from producing the healthy blood cells your body needs. Symptoms of aplastic anemia include bleeding or bruising easily, tiredness, and weakness. You can also experience fevers and infection.
While you’re taking Tagrisso, your oncologist should check your blood counts frequently to watch for any changes. But if you develop a fever, any unusual bleeding or bruising, or feel tired and weak, you should let your healthcare team know right away. These are potential signs and symptoms of aplastic anemia.
Aplastic anemia can be dangerous. If you develop aplastic anemia at any point while taking Tagrisso, you'll need to stop taking it permanently.
Frequently asked questions
You should take Tagrisso once a day, by mouth, at the same time each day. The usual dose is 80 mg daily, and you can take it with or without food.
If you miss a dose, don’t double up to make up for it. Just take your next dose at your regular time. If you have trouble swallowing tablets, you can take Tagrisso as a mixture instead. Dissolve 1 tablet in about 2 oz of water and drink it right away. Then add another 4 oz to 8 oz of water to the same cup, swirl, and drink that too.
You can take Tagrisso at any time of day. Just try to take it at the same time every day. Pick a time that fits easily into your routine so it’s easier to remember. Taking Tagrisso consistently helps keep the right amount of medication in your body to better target lung cancer cells.
If you have trouble remembering to take it, try setting a phone alarm, using a medication reminder app, or organizing your doses in a pillbox.
You should take Tagrisso once a day, by mouth, at the same time each day. The usual dose is 80 mg daily, and you can take it with or without food.
If you miss a dose, don’t double up to make up for it. Just take your next dose at your regular time. If you have trouble swallowing tablets, you can take Tagrisso as a mixture instead. Dissolve 1 tablet in about 2 oz of water and drink it right away. Then add another 4 oz to 8 oz of water to the same cup, swirl, and drink that too.
You can take Tagrisso at any time of day. Just try to take it at the same time every day. Pick a time that fits easily into your routine so it’s easier to remember. Taking Tagrisso consistently helps keep the right amount of medication in your body to better target lung cancer cells.
If you have trouble remembering to take it, try setting a phone alarm, using a medication reminder app, or organizing your doses in a pillbox.
The bottom line
Common Tagrisso (osimertinib) side effects include low blood cell counts, diarrhea, and nail changes. More serious side effects, such as serious skin reactions, heart rhythm changes, and lung problems, are also possible. More serious side effects generally warrant immediate medical attention. Talk to your oncologist for more information about managing Tagrisso side effects.
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References
American Cancer Society. (2024). Mouth sores and pain.
American Cancer Society. (2024). Nail changes.
American Lung Association. (2025). Lung cancer biomarker testing.
Aplastic Anemia and MDS International Foundation. (n.d.). Aplastic anemia.
AstraZeneca Pharmaceuticals. (2024). Tagrisso- osimertinib tablet, film coated [package insert].
Cárdenas-Fernández, D., et al. (2023). Management of diarrhea induced by EGFR-TKIs in advanced lung adenocarcinoma. Therapeutic Advances in Medical Oncology.
Chu, C., et al. (2018). Osimertinib: A novel dermatologic adverse event profile in patients with lung cancer. The Oncologist.
Hamada, K., et al. (2019). Cutaneous vasculitis induced by osimertinib. Journal of Thoracic Oncology.
Ilnytska, O., et al. (2016). Colloidal oatmeal (Avena Sativa) improves skin barrier through multi-therapy activity. Journal of Drugs in Dermatology.
Lacouture, M. E., et al. (2011). Clinical practice guidelines for the prevention and treatment of EGFR inhibitor-associated dermatologic toxicities. Supportive Care in Cancer.
Vogel, W. H., et al. (2016). Management strategies for adverse events associated with EGFR TKIs in non-small cell lung cancer. Journal of the Advanced Practitioner in Oncology.
Zhang, Y., et al. (2025). Rare skin adverse reactions induced by osimertinib: a case report and literature review. Frontiers in Oncology.
