Gefitinib (Iressa)

Gefitinib is pronounced jeh-fit-ih-nib. It is also known by its brand name Iressa. It is a type of biological therapy called a protein tyrosine kinase inhibitor (TKI). Tyrosine kinase is a chemical that plays a part in triggering the growth of cancer cells. Gefitinib blocks (inhibits) the release of tyrosine kinase.

It is a treatment for locally advanced non small cell lung cancer or cancer that has spread. The cancer needs to have receptors for epidermal growth factor (EGFR) on the surface of the cells. 

You may also have it as part of clinical trials for bowel cancer, breast cancer, head and neck cancer, ovarian cancer, prostate cancer, soft tissue sarcoma, bladder cancer, or kidney cancers.

Gefitinib is a tablet. You take it with a glass of water. If you can’t swallow tablets you can put it in half a glass of water and leave it to dissolve. This usually takes about 20 minutes and you will need to swill it round a bit. It is important to make sure that you drink all of the liquid.

You have gefitinib once a day. You usually carry on taking it for as long as it works.

It is very important that you take tablets according to the instructions your doctor or pharmacist gave you. Whether you have a full or empty stomach, for example, can affect how much of a drug gets into your bloodstream. You should take the right dose, not more or less. And never stop taking a cancer drug without talking to your specialist first.

The side effects gefitinib may cause are listed below. Remember, you may only have 1 or 2 or a few of them. For some people they are mild but for others they may be more severe.

More than 10 in every 100 people have one or more of these.

• Skin changes – up to 3 out of 4 people (75%) have a rash or red, dry, itchy skin or acne. Rarely, this may be severe and you may need to stop treatment for a while
• Diarrhoea affects 1 out of 2 people (50%) – drink plenty of fluid and tell your doctor or nurse if it becomes severe, or continues for more than 3 days
• Feeling weak, and lacking in energy and strength
• Feeling or being sick happens in about 1 out of every 10 people (10%) but is usually well controlled with anti sickness drugs
• Loss of appetite happens in about 1 out of 10 people (10%)
• A sore mouth occurs in about 1 out of 10 people (10%)
• Liver changes that are very mild and unlikely to cause symptoms may occur – the liver will almost certainly go back to normal when treatment is finished, but you will have regular blood tests to check how well your liver is working
• Loss of fertility – we don’t know exactly how this drug may affect fertility. Talk to your doctor before starting treatment if having a baby is important to you
• We don’t know whether gefitinib can harm a developing baby – if there is any chance that you or your partner could become pregnant, talk to your doctor or nurse about contraception before having treatment

Between 1 and 10 in every 100 people have one or more of these.

• Increased risk of bleeding – this includes nosebleeds and bleeding from your gums. If you notice blood in your stool, or in your vomit, contact your doctor straight away
• Eye problems including blurred vision, sore, itchy, dry eyes, or infection (conjunctivitis) – eye drops can help
• Brittle or loose nails occur in fewer than 1 in 10 people (10%)
• Hair thinning
• Kidney changes that are mild and unlikely to cause symptoms may occur – these will almost certainly go back to normal when treatment is finished, but you will have regular blood tests to check how well your kidneys are working
• A high temperature (fever)
• Severe lung problems occur in 1 in 100 people (1%) – if you have a cough, high temperature and are short of breath contact your treatment centre urgently

A few people may have abnormal eyelash growth or eye pain. If it is severe your doctors may reduce the dose or stop treatment.

You will not get all the side effects mentioned above and they may be mild. A side effect may get worse through your course of treatment. Or you may have more side effects as the course goes on. This depends on

• How many times you've had a drug before
• Your general health
• How much of the drug you have (the dose)
• Other drugs you are having

Talk to your doctor, pharmacist or nurse about all your side effects so they can help you manage them. Your nurse will give you a contact number. You can ring them if you have any questions or problems. They can give you advice or reassure you. If in doubt, call them.

Tell your doctor, nurse or pharmacist about any other medicines you are taking, including vitamins, herbal supplements and other over the counter remedies – some drugs can react together.