IRESSA (Gefitinib)

Warning:  This drug has been known to cause liver disease in patients.  Although rare, you should notify your doctor immediately if you experience any symptoms that indicate a liver problem such as darker urine, excessive fatigue, abdominal pain, or yellowing in the eyes/skin.

Indications: Used to treat patients with lung cancer, Iressa, or Gefitinb, blocks the effects of a protein called tyrosine kinase.  On the outside of a cell there are receptors that are called epidermal growth factors, or EGFs, for short.  Proteins that are produced by the body are attracted to the EGFRs.  An enzyme inside the cell, known as tyrosine kinase, reacts to the protein attachment, creating a chemical reaction that leads to the cell’s growth and multiplication.  The drug works in that it, too, attaches itself to the EGFR, blocking tyrosine kinase’s actions from it. The result is that the cell stops growing altogether or the growth is significantly slowed down.

Iressa 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.

Patients on this drug can experience a number of adverse reactions such as rash, loss of appetite, diarrhea, nausea, vomiting, red/sore mouth/throat, loss of hair, and weakness.  While these symptoms are normal effects of the medicine, any symptoms that seem excessive or problematic should be brought to the attention of the physician as they can lead to severe dehydration.  The physician may be able to prescribe an additional prescription to combat some of the more severe side effects.  While not common, patients on this drug also report abnormal bleeding, blood in the stools or urine or when they cough, eyes that burn or itch, and swelling in feet or ankles.  If this should occur, it is important to notify the physician immediately.

Dosage:  Iressa is available in the form of a brown, round, biconvex and film-coated tablet. Iressa is administered in a 250mg tablet form that is taken orally once each day.  It may be taken with or without food and if you have a sensitive stomach make sure to talk to your doctor or pharmacist about it.

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

Overdose: anti-cancer medications, even when taken at normal dose, tend to damage the bone marrow, and cause serious decrease in the number of blood cells in your body. Iressa 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
  • heart problems
  • shortness of breath
  • diarrhea
  • Signs of infection such as fever, sore throat, chills, and cough.

Missing dose: take Iressa 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 Iressa  but also any other drug.

Contraindications:   Pregnant and nursing women should not take Iressa.  If you are trying to become pregnant you should talk with your doctor before using this drug.  Allergies should be brought to the attention of your doctor.  Prior health issues involving kidney disease, smoking, stomach or intestinal ulcers, lung disease, eye issues, and cancer that has spread to the bowels should also be made known to your doctor.

Mechanism of action (MOA):  Iressa 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:   This drug is known to be affected by certain kinds of drugs so you want to make sure that your doctor is aware of all drugs or treatments that you are using.  This should include medicated creams, herbs, herbal treatments, and medicine that you can buy on the open shelf. Blood thinners mixed with Iressa can lead to increased bleeding risks.  Drugs such as Dilantin or Rifampin are known to destroy the drug so your doctor may need to adjust the dose if you are taking them.

Side effects: Iressa 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
  • severe depression
  • black, tarry stools
  • nose bleeding
  • abdominal pain
  • skin discoloration
  • dehydration symptoms such as muscle cramps, decreased blood pressure, dizziness, fainting, etc.
  • 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,
  • lips or Skin reactions: ulcers, blisters, pain, redness, scaling, etc.

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