Gefitinib  

Brand name: Iressa ® 

Generic name:Gefitinib 

Therapeutic Class: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor  

Manufacturer / Distributor:  AstraZeneca  

Availability: Gefitinib is available by prescription only  

Indications: Gefitinib is used in the treatment of locally advanced or metastatic non-small cell lung cancer in people who have already been unsuccessfully treated with certain other chemotherapy medications. 

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

Dosage form: Gefitinib comes as a tablet to take by mouth

Dosage: Gefitinib is available in the form of a brown, round, biconvex and film-coated tablet; each tablet contains 250 mg of gefitinib. Usually, the recommended dose is one tablet of 250 mg, taken once daily. You can take the drug with or without food; however, Gefitinib is recommended to be taken around the same time every day. If you cannot swallow the tablet whole, dissolve it in water. Take the medication exactly as prescribed your health care provider. Although Gefitinib appear small, do not take more or more often; this can lead to serious health problems. 

Basing on several factors, your doctor can recommend you a different Gefitinib dosage. Usually, to determine what dosage is most appropriate to your condition, your doctor will consider your body surface area, health status, and the severity of the cancer. Usually, patients who are taking other chemotherapy medications, are can be given a lower. It is important to take and complete the therapy as indicated. If for some good reasons you cannot continue taking the drug, do not stop without first consulting your oncologist.  

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

Overdose: chemotherapy drugs, even when taken at normal dose, can damage the bone marrow, and cause serious decrease in the number of blood cells in your body. Gefitinib overdose may be dangerous, mainly in fragile patients, or if taken for long term. Contact your doctor or the poison control center nearest you if you experience the following symptoms:   

• skin rash 
• confusion 
• fast heartbeat 
• shortness of breath
• diarrhea  
• Signs of infection: fever, sore throat, chills, cough, etc.   

Missing dose: take Gefitinib as indicated your doctor or pharmacist. In case you forget to take a dose, take the missed one as soon as you remember it. If, however, it is almost time for your next dose, do not double it to recover the missed one; it can be dangerous. Contact your doctor or wait to go back to your regular schedule. This applies not only to Gefitinib but also any other drug.    

Contraindications: Gefitinib is contraindicated in patients who suffer from:  

• allergy to Gefitinib or any of its ingredients 
• EGFR-negative tumors- EGFR stands for epidermal growth factor receptor 

Tell your doctor if you are pregnant/breast-feeding, or have:  

• skin rash
• confusion 
• pulmonary fibrosis (scarring of the lungs)
• liver problems
• kidney disease.  

Mechanism of action (MOA): Gefitinib is an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor; i t reduces tumor proliferation by inhibiting tyrosine kinases, enzymes highly involved in intracellular transmission of signals inducing cell proliferation. 

Interactions:  tell your doctor about all the medications you are taking; many other medications may interact with Gefitinib. Talk to your doctor before taking aspirin, vitamins, nutritional supplements or St. John's wort. Tell your doctor and pharmacist if you are taking any of these medications:   

• rifampicin
• rifampin
• vinorelbine
• warfarin
• carbamazepine
• protease inhibitors: atazanavir, nelfinavir, ritonavir
• azole antifungals: itraconazole, ketoconazole,  
• macrolide antibiotics: clarithromycin, erythromycin 
• barbiturates: mephobarbital, pentobarbital, secobarbital   
• histamine H2-receptor antagonists: cimetidine, ranitidine  
• Proton pump inhibitors (PPIs): esomeprazole, lansoprazole, pantoprazole.    

Side effects: Gefitinib not only attack cancer cells but also normal (healthy) cells, which often leads to, in certain patients, the following side effects:

• dry skin 
• itching
• rash
• acne
• mouth sores
• weight loss
• weakness
• hair loss
• decreased appetite
• trouble sleeping
• mild nausea and vomiting,

Contact your doctor immediately if you experience any of these symptoms:  

• anxiety
• depression
• dehydration symptoms: muscle cramps, decreased blood pressure, dizziness, fainting, etc.
• black, tarry stools
• nose bleeding 
• abdominal pain
• purple, blue, or black discoloration of the skin
• vision changes 
• persistent diarrhea  
• itchy or red eye  
• ulcer on the surface of the eye  
• fast or irregular heart beat 
• shortness of breath  
• severe headaches, 
• Skin reactions or on the lips: ulcers, blisters, pain, redness, scaling, etc.