Pemetrexed is a type of chemotherapy. It is also called by its brand name Alimta. You might have it as a treatment for:

• pleural mesothelioma (cancer of the outer covering of the lungs)
• non small cell lung cancer (NSCLC)

For NSCLC, you might have pemetrexed on its own or in combination with other cancer drugs such as cisplatin, carboplatin or pembrolizumab. 

How pemetrexed works

Pemetrexed is a type of drug known as an anti metabolite. It stops cancer cells making and repairing DNA so they can't grow and multiply.

How you have pemetrexed

You have pemetrexed as a drip into your bloodstream (intravenously).

You have treatment through a thin short tube (a cannula) that goes into a vein in your arm each time you have treatment.

Or you might have treatment through a long line: a central line, a PICC line or a portacath. These are long plastic tubes that give the drug into a large vein in your chest. The tube stays in place throughout the course of treatment.

When you have pemetrexed

You usually have pemetrexed every 3 weeks. Each treatment takes about 10 minutes.

Pemetrexed blocks the action of folic acid in the body. To help reduce the side effects this can cause, you might have:

• folic acid tablets for a few days before and after treatment
• a vitamin B12 injection in the week before you start treatment and then every 9 weeks

You may also take corticosteroids such as dexamethasone for 3 to 5 days each time you have pemetrexed.

Tests

You have blood tests before and during your treatment. They check your levels of blood cells and other substances in the blood. They also check how well your liver and kidneys are working.

Side effects

We haven't listed all the side effects. It's very unlikely that you will have all of these side effects, but you might have some of them at the same time.

How often and how severe the side effects are can vary from person to person. They also depend on what other treatments you're having. For example, your side effects could be worse if you're also having other drugs or radiotherapy.

When to contact your team

Your doctor, nurse or pharmacist will go through the possible side effects. They will monitor you closely during treatment and check how you are at your appointments. Contact your advice line as soon as possible if:

• you have severe side effects 
• your side effects aren’t getting any better
• your side effects are getting worse

Early treatment can help manage side effects better. 

Common side effects

Each of these effects happens in more than 1 in 10 people (10%). You might have one or more of them. They include:

Risk of infection

Increased risk of getting an infection is due to a drop in white blood cells. Symptoms include a change in temperature, aching muscles, headaches, feeling cold and shivery and generally unwell. You might have other symptoms depending on where the infection is.

Infections can sometimes be life threatening. You should contact your advice line urgently if you think you have an infection. 

Breathlessness and looking pale

You might be breathless and look pale due to a drop in red blood cells. This is called anaemia.

Bruising and bleeding

This is due to a drop in the number of platelets in your blood. These blood cells help the blood to clot when we cut ourselves. You may have nosebleeds or bleeding gums after brushing your teeth. Or you may have lots of tiny red spots or bruises on your arms or legs (known as petechia).

Diarrhoea or constipation 

Tell your doctor or nurse if you have diarrhoea or constipation. They can give you medicine to help. 

Feeling or being sick 

Feeling or being sick is usually well controlled with anti sickness medicines. Avoiding fatty or fried foods, eating small meals and snacks, drinking plenty of water, and relaxation techniques can all help.

It is important to take anti sickness medicines as prescribed even if you don’t feel sick. It is easier to prevent sickness rather than treating it once it has started.

Mouth sores and ulcers

Mouth sores and ulcers can be painful. Keep your mouth and teeth clean; drink plenty of fluids; avoid acidic foods such as oranges, lemons and grapefruits; chew gum to keep the mouth moist and tell your doctor or nurse if you have ulcers.

Loss of appetite 

You might lose your appetite for various reasons when you are having cancer treatment. Sickness, taste changes or tiredness can put you off food and drinks.

Fatigue (tiredness)

You might feel very tired and as though you lack energy.

Various things can help you to reduce tiredness and cope with it, for example exercise. Some research has shown that taking gentle exercise can give you more energy. It is important to balance exercise with resting.

Skin problems 

Skin problems include a skin rash, dry skin and itching. This usually goes back to normal when your treatment finishes. Your nurse will tell you what products you can use on your skin to help.

To reduce the skin rash your nurse might give you corticosteroids. You usually take them on the day before treatment, the day of treatment, and the day afterwards.

Hair loss

Your hair may thin but you’re unlikely to lose all your hair. This usually starts after your first or second cycle of treatment. It is almost always temporary and your hair will grow back when you finish your treatment.

Numbness or tingling in fingers and toes

Numbness or tingling in fingers or toes is often temporary and can improve after you finish treatment. Tell your doctor if you're finding it difficult to walk or complete fiddly tasks such as doing up buttons. 

Kidney changes

To help prevent kidney damage, it is important to drink plenty of water. You might also have fluids into your vein before, during and after treatment. You have blood tests before your treatments to check how well your kidneys are working.

Occasional side effects

Each of these effects happens in more than 1 in 100 people (1%). You might have one or more of them. They include: 

• an allergic reaction that can cause a skin rash, burning or a prickling sensation
• high temperature (fever)
• loss of fluid (dehydration) that can make you feel thirsty and have dark yellow and strong smelling pee
• pain in your chest and tummy (abdomen)
• muscle weakness that can make walking or climbing stairs more difficult
• inflammation of the eyes and watery eyes
• taste changes that can make you go off certain foods
• indigestion
• liver changes that are usually mild and unlikely to cause symptoms

Rare side effects

Each of these effects happens in fewer than 1 in 100 people (1%). You might have one or more of them. They include: 

• a fast heart rate or chest pain
• inflammation of the lining of the bowel (colitis) which can cause bleeding
• scarring on the air sacs of your lungs which can cause a dry cough, chest pain and shortness of breath
• a build up of fluid in your body (oedema)
• blood clots in your lungs
• inflammation of the liver
• pain, coldness and paleness in your hands and feet
• a severe skin reaction that may start as tender red patches which leads to peeling or blistering of the skin. You might also feel feverish and your eyes may be more sensitive to light. This is serious and could be life threatening

Coping with side effects

We have more information about side effects and tips on how to cope with them.

What else do I need to know

Other medicines, foods and drinks

Cancer drugs can interact with some other medicines and herbal products. Tell your doctor or pharmacist about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies.

Ibuprofen (Neurofen)

You should avoid taking ibuprofen from 5 days before and up until 2 days after pemetrexed. Ibuprofen can make the pemetrexed side effects worse.  

Pregnancy and contraception

This treatment may harm a baby developing in the womb. It is important not to become pregnant or father a child while you are having treatment and for at least 6 months afterwards. Talk to your doctor or nurse about effective contraception before starting treatment.

Loss of fertility

You may not be able to become pregnant or father a child after treatment with this drugs. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.

Men might be able to store sperm before starting treatment. And women might be able to store eggs or ovarian tissue. But these services are not available in every hospital, so you would need to ask your doctor about this.    

Breastfeeding

Don’t breastfeed during this treatment because the drug may come through into your breast milk.

Treatment for other conditions 

Always tell other doctors, nurses, pharmacists or dentists that you’re having this treatment if you need treatment for anything else, including teeth problems.

Immunisations

Don’t have immunisations with live vaccines while you’re having treatment and for up to 12 months afterwards. The length of time depends on the treatment you are having. Ask your doctor or pharmacist how long you should avoid live vaccinations.

In the UK, live vaccines include rubella, mumps, measles, BCG, yellow fever and the shingles vaccine (Zostavax).

You can:

• have other vaccines, but they might not give you as much protection as usual
• have the flu vaccine (as an injection)

Contact with others who have had immunisations - You can be in contact with other people who have had live vaccines as injections. Avoid close contact with people who have recently had live vaccines taken by mouth (oral vaccines) such as the oral typhoid vaccine.

If your immune system is severely weakened, you should avoid contact with children who have had the flu vaccine as a nasal spray. This is for 2 weeks following their vaccination.

Babies have the live rotavirus vaccine. The virus is in the baby’s poo for about 2 weeks and could make you ill if your immunity is low. Get someone else to change their nappies during this time if you can. If this isn't possible, wash your hands well after changing their nappy.

More information about this treatment

For further information about this treatment go to the electronic Medicines Compendium (eMC) website.

You can report any side effect you have to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.