What is this medication for?
Gilteritinib is used to treat patients with acute myeloid leukaemia (AML) — a type of blood cancer, affecting the bone marrow, which causes excessive abnormal, immature white blood cells to be produced — and where a specific gene change known as a FLT3 mutation is present.
This medication works by blocking a faulty protein called FLT3 (FMS-like tyrosine kinase 3), which helps cancer cells grow and multiply. By blocking this protein, Gilteritinib helps to slow down or stop the growth of cancer cells.
How should I take or use this medication?
- Take Gilteritinib once a day, with or without food.
- Swallow the tablet whole. Do not break or crush the tablet.
- Inform your doctor or pharmacist if you have difficulty swallowing.
- Take Gilteritinib at about the same time each day.
- Do not stop taking your medication without checking with your healthcare professional.
- Special handling of the medication is needed.
- Try not to touch the medication with your bare hands. Use the medication cup provided. Wash your hands after handling the medication.
What should I do if I forget to take or use this medication?
- If you forget to take a dose, take it as soon as you can if it is within 12 hours of the missed dose. If more than 12 hours have passed since the missed dose, skip the missed dose and take it at the next scheduled time. Do not take two doses to make up for the missed dose.
- If you vomit after taking a dose, do not take another dose. Take your next dose at the usual time the following day.
What precautions should I take when taking or using this medication?
Inform your healthcare professional if:
- You are allergic to this medication or any of the other ingredients of this medication.
- You are taking any other medications, including supplements, traditional medications and herbal remedies.
- You have any other medical conditions especially heart conditions, electrolytes imbalances.
- You are going to receive any vaccination or surgery, including dental surgery.
- You have any plans to start a family in the future.
- Gilteritinib may have an anti-fertility effect in males. You should discuss fertility preservation options with your doctor before starting treatment.
- You should not become pregnant during treatment. You should use an effective birth control method during treatment and for at least 6 months after stopping Gilteritinib.
- If you have a partner who could become pregnant, you should use an effective birth control method during treatment and for at least 4 months after stopping Gilteritinib.
- Pregnancy testing is recommended for female patients of reproductive potential within seven days prior to initiating treatment with gilteritinib.
- You should not breastfeed during treatment and for at least 2 months after stopping Gilteritinib.
What are some common side effects of this medication?
The table below lists some of the common side effects as well as the rare but serious side effects.
| Side Effect | Management |
Symptoms of drug allergy including one or more of the following:
| If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately. |
| Skin rash |
|
| Headaches, muscle aches and/or joint pain |
|
Liver problems
|
|
| Feeling tired or lack of energy |
|
Mouth ulcers or sores.
|
|
| Nausea or vomiting | Take small and frequent meals. Avoid foods or smells that may make you feel nauseous, such as oily, fried or strong-smelling food. Avoid tight-fitting clothes around the waist. Your doctor may prescribe medications to help relieve or prevent nausea or vomiting. Take these as instructed. |
| Poor appetite | This may be worsened by a change in taste of food and/or nausea. Try different flavours of food and small frequent meals. For poor appetite, try to include nutritional supplements (such as milk supplements) into your diet. |
| Diarrhoea (loose and frequent stools) | Drink plenty of clear fluids (at least 2 litres or 8 cups every day) if not fluid-restricted. Eat food that is gentler on the stomach such as porridge or soup. Avoid milk, dairy products, high-fibre food and oily or spicy food. Your doctor may prescribe medications to help relieve diarrhoea. Take these as instructed. Proceed to the A&E Department immediately if you have very bad diarrhoea (for example, increase in bowel movement of more than 4 times per day) that does not improve even after taking anti-diarrhoeal medications. |
| Constipation (difficulty in passing stools) | Consume more fibre by eating more fruits and vegetables, unless otherwise advised by your doctor. Drink enough fluids every day (at least 2 litres) unless otherwise advised by your doctor. Your doctor may prescribe medications to help relieve or prevent constipation. Take these as instructed. Inform your doctor immediately if you experience severe stomach pain. |
Differentiation syndrome — It occurs when the cancer cells mature too fast, releasing massive amounts of signals that cause severe inflammation and fluid leaks into the body's tissues. This can be life-threatening. Signs and symptoms may include unexplained fever, difficulty breathing, weight gain, fluid around the lungs or heart, low blood pressure, or kidney problems. | Proceed to the A&E department immediately if you experience any of these symptoms after you have left the hospital. This condition may be life-threatening if not treated promptly. |
| Slow or abnormal heart rhythm — you may experience a fast or irregular heartbeat |
|
Low blood pressure
| Inform your doctor if you are on any blood pressure medication and seek medical attention if you experience these symptoms. |
Fluid retention
|
|
| Eye problems |
|
| Kidney problems |
|
Problems with brain function (Posterior Reversible Encephalopathy Syndrome — PRES), which may include symptoms such as:
This is a rare but severe side effect. | Proceed to the A&E department immediately if you experience such symptoms. |
| Inflammation of the pancreas (pancreatitis) — symptoms include severe pain in the stomach, abdomen or back area, or nausea or vomiting that does not go away. | Proceed to the A&E department immediately if you experience such symptoms. |
It is normal to experience some side effects from Gilteritinib. As discussed with your doctor, taking Gilteritinib will be beneficial for your condition. Do not stop taking Gilteritinib without checking with your doctor.
What food or medication should I avoid when I take or use this medication?
- Avoid eating any raw, uncooked or under-cooked food as your immunity may be weakened.
- Avoid taking certain fruits such as grapefruit, pomelo, starfruit and pomegranate when you are taking this medication. Grapefruit, grapefruit juice, and products containing grapefruit extract may affect how the body processes the drug and increase the risk of side effects.
- Inform your doctor or pharmacist if you are taking any medications that are strong inducers or inhibitors of CYP3A enzymes (e.g. rifampin, phenytoin, voriconazole, posaconazole, clarithromycin), as these may affect how Gilteritinib works in your body.
- Check with your doctor or pharmacist before you start any medications or herbal supplements.
How should I store this medication?
Store in the original package to protect from light, moisture and humidity. Store at or below 30°C. Keep this medication away from children.
How do I throw away this medication safely?
Pack the medication into a bag and bring it back to the pharmacy where you received the medication from.
What else should I know about this medication?
Tips to help manage your condition while you are on Gilteritinib
| Exercise | Light exercise is recommended as it helps to improve mobility, balance, and even emotional well-being. Avoid strenuous exercise, and rest when you are feeling tired. |
| Adequate hydration | Have plenty of hydration with 2 to 3 litres of fluids per day unless you have been informed by your doctor to limit how much fluids you can drink. This will decrease your chances of getting constipation and prevent dehydration. |
| Medical and dental treatment | If you need to go into hospital for any reason other than cancer, always inform the doctors and nurses that you are receiving anti-cancer treatment. Talk to your cancer doctor if you think you need dental treatment. Always inform your dentist that you are receiving anti-cancer treatment. |
| Seek support if you feel overwhelmed | It is normal to feel fearful or worried about your condition. Do not be afraid to share your concerns with your healthcare team or loved ones. There may be resources and support available to help you. |
Disclaimer
Please take note that the above is not a complete list of all possible side-effects. If you have any concerns about your medication or if you have other side-effects that you think are caused by this medication, please consult your doctor or pharmacist. If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.
This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (NHG Health, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.
Contributed By
- Pharmaceutical Society of Singapore