Imatinib  

Brand name: Gleevec®  

Generic name: Imatinib  

Other names: Imatinib Mesylate, STI-571  

Therapeutic Class: protein-tyrosine kinase inhibitors 

Manufacturer / Distributor:  Novartis 

Availability: Imatinib is available by prescription only  

Indications: Imatinib is used to treat chronic myelogenous leukemia (also called chronic myeloid leukemia or CML) newly diagnosed that has not responded to interferon alpha therapy. Imatinib is also used to treat gastrointestinal stromal tumors (GIST), a very common group of tumors of the gastrointestinal tract; and dermatofibrosarcoma protuberans, a rare type of malignant tumor arises under the top layer of the skin. In addition, Imatinib is used in the treatment of dermatofibrosarcoma protuberans that has spread to other parts of the body, or has come back after surgery.  

Imatinib may also be prescribed for other medical conditions not mentioned in this article; talk to your doctor or pharmacist for more information.  

Dosage form: Imatinib comes as a tablet to be taken by mouth 

Dosage:  Imatinib can be taken by mouth in dosages of 100 mg or 400 mg. The 100 mg is usually orange in color and round shape; the 400 mg comes in an orange scored oblong. The dose to be taken must be recommended by an oncologist or a physician having experience in chemotherapy drugs.  

In general, the dosage varies depending on your body surface area (BSA), general state of your health, whether you are taking other drugs or not, and the type of cancer being treated. Regardless of dosage indicated, it is necessary to take the medication as prescribed by your health care provider.  

In cases of malignant gastrointestinal stromal tumor (GIST), the usual dose for adults ranges between 400 mg and 800 mg per day. However, depending on the aggressiveness of the tumor, you can be recommended to take a higher dose.  

If you have a newly diagnosed chronic myeloid leukemia (CML), and you are an adult, your doctor may prescribe you 400 mg of Imatinib to be taken daily. In cases of chronic myeloid leukemia, the daily dose can be 400 mg to 600 mg. however, if you have an aggressive or advanced myelogenous leukemia, the recommended dose can be 600 mg to 800 mg per day.  

To avoid an overdose of iron, the 800 mg should be divided into two 400 mg, taken 2 times a day. Imatinib should be taken by mouth with meals with a full glass of water. Swallow the tablets whole without chewing it. 

It’s likely that you experience side effects during the treatment; do not stop or modify the way you are told to take the medication. Most patients develop side effects when and after a treatment with Imatinib.  

Storage: store Imatinib at room temperature (15-25 ° C), away from heat above 40 ° C, light and moisture. Keep the medication out of the reach of children. Imatinib and other drugs should not be used beyond the expiration date printed on the container.   

Overdose: Imatinib overdose can cause life threatening problems. Chemotherapy drugs including Imatinib tend to damage the bone marrow, and lead to a decrease in white blood cells and platelets, which can cause serious infections in some patients. If you take a Imatinib overdose, contact your doctor or the poison control center nearest you immediately.  

Missing dose:  take Imatinib and all medications as prescribed.  In case you forget to take a dose, take the missed one as soon as you remember it. However, if it is almost time for your next dose, do not double the next dose to recover the missing; it can be dangerous. Contact your doctor or wait to go back to your regular schedule. This applies not only to Imatinib but also any other drug. 

Mechanism of action (MOA): Imatinib is an anticancer drug belongs to the family of tyrosine kinase inhibitors. It works by preventing the development, and selectively inducing cancer cell death. 

Interactions:  always talk you to your doctor before taking St. John's wort, vitamins, nutritional supplements and other prescription drugs when you undergo chemotherapy. Some medicines may affect the curative effects of Imatinib, or increase the risk of developing side effects. Consult your doctor before taking the following drugs:

• Acetaminophen              Azithromycin                    Carbamazepine
• Clarithromycin                Cyclophosphamide            Cyclosporine
• Dexamethasone              Dextropropoxyphene          Doxorubicin
• Erythromycin                 esomeprazole (Nexium)      Etoposide
• Ifosfamide                     Itraconazole                    Ketoconazole
• Lansoprazole                  metronidazole                  Morphine
• Omeprazole                    Oxycodone                     Pantoprazole
• Phenytoin                      Phenobarbital                  Pimozide 
• Prednisone                     Quinidine                        rabeprazole  
• acid retinoic                   rifampicin                       rifampin simvastatin 
• teniposide                      valproic acid                   vinblastine  
• vincristine                       vinorelbine                      warfarin  
• beta-blockers (Atenolol, propranolol, metoprolol and others) 
• Calcium channel blockers (Nifedipine, diltiazem, verapamil, amlodipine, felodipine, and others).  

Side effects: while attacking cancer cells, Imatinib also affects healthy cells, which lead to development of adverse effects in most patients; most common Imatinib side effects include: 

• hair loss 
• fatigue  
• headache 
• muscle cramps and pain
• nausea and vomiting  
• decreased appetite 
• weight loss  
• mouth blistering 
• drying or darkening of the skin or nails 
• joint pain 
• night sweats 
• teary eyes 
• Bowel disorders such as gas, diarrhea, indigestion, constipation and diarrhea.  

If the side effects above persist for weeks, contact your oncologist. In addition, contact your doctor if you experience any of these symptoms:    

• fever 
• chills 
• dizziness  
• shortness of breath 
• puffy face  
• fainting 
• chest pain 
• weight gain 
• blood in the stool 
• skin problems such as rash or blisters 
• yellowing of the skin or eyes 
• swelling of the hands, feet, ankles, or lower legs 
• fast or irregular heartbeat 
• difficulty falling asleep or staying asleep 
• persistent coughing associated with bloody mucus 
• urgent need to urinate, especially at night 
• unusual bruising or bleeding 
• Excessive tiredness or weakness.