Pemetrexed belongs to the group of cancer-fighting medications known as antineoplastics (anticancer), and specifically to the group of antineoplastics known as antifolates. Pemetrexed interferes with the processes that are necessary for cell growth and replication. Pemetrexed is used in combination with other antineoplastic medications to treat cancer of the lining of the chest cavity, known as pleural mesothelioma.

Pemetrexed is also used alone to treat certain types of lung cancer after having received other chemotherapy. It may be used with other medications to treat nonsquamous non-small cell lung cancer that has not yet been treated.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are receiving this medication, speak to your doctor.

The dose of pemetrexed is based on body size and is usually given by slow infusion into a vein. The infusion process for this medication often lasts about 10 minutes. You will receive this medication once every 21 days (3 weeks). If it is administered in combination with another antineoplastic medication, the entire process may take up to 3 hours.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications.

Pemetrexed is always given under the supervision of a doctor. Very careful handling of this medication is required. It is always administered in a hospital or similar setting with access to sterile equipment for preparation.

As well as interfering with replication of cancer cells, pemetrexed can interfere with some of your normal cells. This can cause a number of side effects such as hair loss, mouth sores, nausea, and vomiting. Your doctor, nurse, or pharmacist can advise you on how to reduce the effects of nausea and vomiting.

Before your dose of pemetrexed, you will be given some medication to reduce the symptoms of side effects. To reduce your chances of getting skin reactions from pemetrexed, your doctor will prescribe a corticosteroid to take a day before your treatment. To lower your chances of side effects, you must take folic acid and receive vitamin B12 injections as directed by your doctor. Keep track of any side effects and report them to your doctor as suggested in the section, "What side effects are possible with this medication?"

It is important this medication be given exactly as recommended by your doctor. If you miss an appointment to receive pemetrexed treatment, contact your doctor immediately to reschedule your appointment and for further instructions on folic acid and vitamin B12 supplementation.

This medication is stored at room temperature.

Solution for Injection
Each mL of sterile, colourless-to-pale-yellow solution contains pemetrexed disodium equivalent to 25 mg of pemetrexed. Nonmedicinal ingredients: citric acid, L-methionine, monothioglycerol and water for injection. Hydrochloric acid and/or sodium hydroxide may have been added to adjust pH.

Powder for Solution
Each single-use vial of sterile, white-to-light-yellowish lyophilized powder contains pemetrexed disodium hemipentahydrate equivalent to 100 mg or 500 mg of pemetrexed. Nonmedicinal ingredients: mannitol. Hydrochloric acid and/or sodium hydroxide may have been added to adjust pH.

Do not use this medication if you:

• are allergic to pemetrexed or any ingredients of the medication
• have received or is going to receive the yellow fever vaccine

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is used in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who receives this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people receiving this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• constipation
• diarrhea
• loss of appetite
• mild skin rash, redness, or itching
• nausea and vomiting
• redness, heat, irritation or pain, swelling, or lump at the site of injection
• tiredness
• weight loss

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• fever and chills
• mood changes and depression
• mouth, throat, or lip sores
• severe red, scaly, swollen, or peeling areas of skin
• signs of clotting problems (e.g., unusual nosebleeds, bruising, blood in urine, coughing blood, bleeding gums, cuts that don’t stop bleeding)
• signs of dehydration (e.g., decreased urine, dry skin, dry and sticky mouth, sleepiness, dizziness, headache, thirst, confusion)
• signs of infection (symptoms may include fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness)
• signs of kidney problems (e.g., increased urination at night, decreased urine production, blood in the urine, change of urine colour)
• sore throat
• symptoms of anemia (low red blood cell count) such as tiredness, paleness, or shortness of breath
• unusual bleeding or bruising
• unusual tiredness or weakness
• vomiting (severe)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• chest pain
• difficulty swallowing
• severe shortness of breath
• signs of bleeding in the stomach (e.g., bloody, black, or tarry stools, spitting up of blood, vomiting blood or material that looks like coffee grounds)
• signs of a severe allergic reaction (e.g., hives; difficulty breathing; or swelling of the face, throat, or tongue)
• signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Allergic reactions: Allergic reactions, including difficulty breathing and swelling of the throat and mouth, can occur with this medication. If you experience these symptoms, get immediate medical attention.

Blood clotting: This medication can reduce the number of platelet cells in the blood. Platelets help the blood to clot, and a shortage could make you bleed more easily. Tell your doctor of any signs that your blood is not clotting as quickly. Such symptoms may include black and tarry stools, blood in the urine, easy bruising, or cuts that won't stop bleeding.

Fertility: This medication may cause temporary or permanent fertility problems. Talk to your doctor about your concerns and options.

Infection: As well as killing cancer cells, this medication can reduce the number of cells that fight infection in the body (white blood cells). Avoid contact with people who have contagious infections (e.g., colds, flu), and tell your doctor if you begin to notice signs of an infection such as fever or chills.

Kidney disease: This medication may affect your kidneys. You doctor will monitor your kidney function through blood tests while you are receiving this medication. People with significantly decreased kidney function should not receive pemetrexed. People with diabetes, high blood pressure, or who are dehydrated should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver problems: People with impaired liver function or liver problems (e.g., liver disease, liver cancer) should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Lung problems: This medication can cause lung problems that can be severe. If you experience shortness of breath and cough while taking this medication, contact your doctor or get immediate medical attention.

Skin reactions: Because skin reactions are known to occur in people who receive treatment with pemetrexed, it is recommended that a corticosteroid be taken for 3 days starting the day before scheduled treatment.

Vitamin supplementation: To avoid undesirable side effects, people using pemetrexed must take a low-dose folic acid supplement or a multivitamin containing folic acid once a day for the week before the start of treatment, and for the 3 weeks after the last dose of treatment. In addition, vitamin B12 injections must be given at least 1 week before the first day of treatment, and then continued every 9 weeks from the previous dose until 3 weeks after the last dose of pemetrexed.

Pregnancy: This medication may harm a fetus or baby. People who could become pregnant should have a negative blood pregnancy test before starting this medication and should use effective contraception to prevent pregnancy during treatment. If you become pregnant while receiving this medication, contact your doctor immediately.

Breast-feeding: It is not known if pemetrexed passes into breast milk. People should not breast-feed while receiving this medication.

Children: The safety and effectiveness of using this medication have not been established for children.

For a full list of interactions, use the Drug Interaction Checker available on the Drugs.com website.

If you are taking other medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.