Pemetrexed (Alimta)

Pemetrexed is a chemotherapy drug used to treat pleural mesothelioma and non small cell lung cancer. Pleural mesothelioma is a cancer which affects the lining of the lungs. Pemetrexed is also being used in clinical trials for osteosarcoma, a type of bone cancer.

Pemetrexed is one of a group of drugs known as anti-metabolites. These stop cells making and repairing the DNA that they need to grow and multiply. Pemetrexed is also known by its brand name Alimta.

Pemetrexed is used to treat mesothelioma in combination with another chemotherapy drug called cisplatin. 

If you have pemetrexed as a treatment for non small cell lung cancer you may have it on its own or in combination with cisplatin.

You have pemetrexed into your bloodstream (intravenously) through a drip (infusion). You can have it through a thin, short tube (a cannula) put into a vein in your arm each time you have treatment. Or you may have it through a central line, a portacath, or a PICC line. These are long, plastic tubes that give the drugs directly into a large vein in your chest. You have the tube put in just before your course of treatment starts and it stays in place as long as you need it.

You usually have chemotherapy as a course of several cycles of treatment. The number of treatment cycles you have depends on your treatment plan. Your treatment plan for pemetrexed will depend on which cancer you have. There is detailed information about the way doctors plan chemotherapy in the planning chemotherapy section.

Pemetrexed is a type of drug known as an anti folate. It blocks the action of folic acid in the body. To help reduce the side effects this causes, you need to

• Take folic acid tablets – starting 5 days before you begin treatment, and continuing throughout treatment and for 3 weeks after treatment has finished
• Have vitamin B12 injections – one injection in the week before you start treatment and then one before every third treatment cycle

The side effects associated with pemetrexed are listed below. You can use the links to find out more about each side effect. For general information, see our cancer drug side effects section.

More than 10 in every 100 people have one or more of the side effects listed below.

Temporary drop in the number of blood cells made by the bone marrow, causing

• Increased risk of getting an infection from a drop in white blood cells – it is harder to fight infections and you can become very ill. You may have headaches, aching muscles, a cough, sore throat, pain passing urine or feel cold and shivery
• Tiredness and breathlessness due to a drop in red blood cells (anaemia) – you may need a blood transfusion
• Bruising more easily due to a drop in platelets – you may have nosebleeds, bleeding gums after brushing your teeth, or lots of tiny red spots or bruises on your arms or legs (known as petechia)

Some of these side effects can be life threatening, particularly infections. You should contact your doctor if you have any of these effects. Your doctor will check your blood counts regularly to see how well your bone marrow is working.

Other common side effects include

• Fatigue (tiredness) affects about 1 in 3 people (34%) during and after treatment – most people find their energy levels are back to normal within 6 months to a year
• Feeling or being sick happens in almost 1 out of every 2 people (47%), but is usually well controlled with anti sickness drugs
• Loss of appetite happens in about 1 in 5 people (20%)
• A skin rash happens in nearly 1 in 6 people (16%) – you may have some itching and your skin may become sore
• Diarrhoea in just over 1 out of 7 people (13%) – drink plenty of fluid and tell your doctor or nurse if diarrhoea becomes severe, or continues for more than 3 days
• A sore mouth in nearly 1 out of 7 people (13%)
• This drug may have a harmful effect on a developing baby so do talk to your doctor about contraception before having treatment if there is any chance that you or your partner could become pregnant
• Women may stop having periods (amenorrhoea) but this may be temporary
• Loss of fertility – we don’t know exactly how this drug affects fertility so do talk with your doctor before starting treatment if having a baby is important to you

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

• Hair thinning
• Constipation in 1 out of 20 people (5%) – your doctor or nurse may give you laxatives to help prevent this but tell them if you are constipated for more than 3 days
• Liver changes that are very mild and unlikely to cause symptoms – the liver will almost certainly go back to normal when treatment ends, but you will have regular blood tests to check how well your liver is working
• A high temperature (fever) – taking paracetamol every 6 to 8 hours can help until your temperature goes down

Not everyone will get these side effects. 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 about any other medicines you are taking, including vitamins, herbal supplements and other over the counter remedies – some drugs can react together.

You should not have immunisations with live vaccines while you are having this treatment or for at least 6 months afterwards. In the UK, these include rubella, mumps, measles (usually given together as MMR), BCG and yellow fever. You can have other vaccines, but they may not give you as much protection as usual until your immune system has fully recovered.

It is safe for you to be in contact with other people who've had live vaccines as injections. There can be problems with oral vaccines, but not many people in the UK have oral vaccines now. So there is usually no problem in being with any baby or child who has recently had any vaccination in the UK. You might need to make sure that you aren't in contact with anyone who has had oral polio, cholera or typhoid vaccination recently, particularly if you live abroad.