Imatinib

Imatinib is an anti-cancer medication mainly used in treating:

• Cancer of the blood affecting the white blood cells known as granulocytes in adults and children
• Cancer of the blood affecting the white blood cells known as lymphocytes in adults and children
• Gastrointestinal stromal tumors or GIST, a type of cancer in an adult that occurs in the wall of the small intestine and stomach
• Myelodysplastic/ myeloproliferative diseases, MDS/MPD, a type of cancer in adult in which some blood cells starts to grow out of control
• Dermatofibrosarcoma protuberans (DFSP), a type of cancer in an adult that forms under the layer of skin and can’t be removed surgically
• Hypereosinophilic syndrome
• Systemic mastocytosis, a rare disease characterized by too many mast cells found in the skin, joints, bones, liver, spleen, lymph nodes and gastrointestinal tract

Imatinib is a protein-tyrosine kinase (TK) inhibitor that targets proteins in cancer cells and stops cancer cells from growing. It works by inhibiting the action of the abnormal proteins in the body that signals the cancer cells to grow and replicate. These proteins are usually more active and present in larger quantities in cancer cells. Reducing the activity of the proteins also reduces the growth and survival of cancer cells.

This drug has been approved by the US Food and Drug Administration for medical use since 2001. It has been listed as one of the safest and most effective medicines needed in the health system.

When and How to Use Imatinib

Your dose and the duration of your treatment depend on the condition being treated and how you respond to the treatment. Imatinib comes as a tablet for you to take orally. Take this exactly as directed by your physician. Do not take more or less than what is prescribed or for longer than the prescribed duration of treatment.

The recommended dose range is 300 mg to 800 mg a day, again, depending on your condition.  If your dose is 800mg, take it in two divided doses of 400mg. Do not take 8 of the 100mg tablet as it contains iron. You’ll receive too much iron if you will take 8 tablets of 100mg each. The dose for children must be determined by the doctor.

Take it with food and with a large glass of water to minimize irritation in the gut. Swallow the tablet whole. If you cannot swallow the tablet, you may dissolve it in a glass of water or apple juice. If you are taking the 4000mg, dissolve it in 7 ounces of juice or water.

Your doctor may decrease or increase your dose depending on how well this medicine works for you and the side effects you experience. Continue taking your medication even if you feel well. Do not stop taking this unless you are told to do so. Tell your doctor about how you feel during the treatment. For a missed dose, take it as soon as you remember.

What to know before taking Imatinib

• Use this with caution among patients with:
  • Decreased kidney and liver function
  • History of heart diseases such as heart failure, irregular heartbeat and angina pectoris
  • Who takes levothyroxine following removal of their thyroid gland
  • Elderly patients
  • Children
• Imatinib may cause sleepiness, dizziness and blurred vision. If you are affected in any way, rake extra care when you drive or do anything which requires mental alertness.
• Imatinib is not safe for pregnant women as this potentially harm unborn babies. As much as possible, use a reliable method of contraception to prevent pregnancy while under medication. If you think you are pregnant while using this medicine, tell your doctor.
• It’s not also suitable for use by breastfeeding women.
• Check with your doctor as soon as possible if you experience serious skin reactions like blistering, red skin lesion, ulcers in the skin, peeling, chills, fever or severe acne.
• Imatinib can slow down the growth of your child. The doctor will need to keep track of your child’s height and weight to make sure your child is growing properly.

Possible Side Effects of Imatinib

Common side effects of Imatinib include:

• Nausea
• Vomiting
• Headache
• Bone and joint pain
• Weight loss
• Dry skin
• Itching
• Dry mouth
• Diarrhea
• Mouth sores
• Hair loss
• Sweating
• Pink eye
• Difficulty sleeping or staying awake
• Nail changes

Serious side effects are:

• Chest pain
• Blood in the stool
• Swelling around the eye
• Shortness of breath
• Irregular heartbeat
• Unusual bleeding or bruising
• Excessive weakness or tiredness
• Yellowing of the eyes or skin
• Blistering, peeling or shedding of skin
• Bloody mucus

Call your doctor if you will experience any unusual problems while taking this medication.

Getting the Best Result from Imatinib

• Patients who are using this medicine is required to weigh themselves regularly as this medicine can cause fluid retention. Fluid retention while taking this requires treatment.
• Have a regular blood test so your doctor can monitor your liver function and the number of blood cells in your blood.
• If you develop nausea, vomiting, unexplained itching, loss of appetite, abdominal pain, jaundice, and flu-like symptoms consult your doctor. This medicine can sometimes cause liver problems.
• If you experience signs of unexplained bruising or bleeding, mouth ulcers, purple spots, sore throat, fatigue, and fever consult your doctor. Imatinib can sometimes cause a decrease in the normal amount of healthy blood cells in the blood.
• After using Imatinib, do not have any immunization or vaccination. This medicine can lower your resistance and there is a greater chance for you to get the infection the vaccine is meant to prevent.
• Those living in your household should not take the oral polio vaccine as there is a chance you might get the polio virus. Do not stay too close with someone who recently took the oral polio vaccine. You should consider wearing a protective mask that covers your mouth and nose.