Methotrexate is in a class of medications called antimetabolites. Antimetabolites are substances that interfere with the normal metabolic processes within cells, typically by combining with enzymes. They inhibit DNA replication and repair by mimicking normal cell compounds.
Methotrexate also stops some normal cells working properly, causing side effects. Some patients may have another drug called folinic acid after methotrexate as it helps normal cells recover and reduces side effects.
Indications
- Burkitt lymphoma (BL)
- Natural Killer T-cell lymphoma (NKTCL)
- Non-Hodgkin lymphoma (NHL)
- Primary Central Nervous System lymphoma (PCNSL)
- Central nervous system prophylaxis
Administration
The doctor will decide what dose, how often and how long a patient will receive it.
This depends on the general health of the patient and other factors, such as weight, age, blood tests, how well the kidneys and liver are working, and whether other medicines are being given at the same time.
Methotrexate can be given into a vein in one of the following ways:
- Via a short, thin tube that the nurse puts into a vein in the arm or hand (cannula)
- Via a fine tube that goes under the skin of the chest and into a nearby vein (central line)
- Via a fine tube that is put into a vein in the arm and goes up into a vein in the chest (PICC line).
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Methotrexate can also be given:
- As tablets or a liquid (oral drug)
- By injection into the fluid around the spinal cord (intrathecal chemotherapy). This allows the drug to reach the spinal cord and brain.
- As an injection into a muscle (intramuscular injection)
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High dose Methotrexate
Monitoring of methotrexate levels is essential as delayed methotrexate excretion is potentially an emergency. Methotrexate levels are monitored every 24 hours from administration and until the drug is excreted to safe levels (below 0.5).
Methotrexate is renally (via the kidneys) eliminated. Renal function must be evaluated prior to treatment.
Possible side-effects
- Joint or muscle pain
- Reddened eyes
- Swollen gums and mouth
- Ulcers
- Hair loss
- Fatigue
- Nausea and vomiting
- Diarrhoea.
- Skin dryness, a variety of skin rashes and increased sensitivity to the sun may also occur.
- Mild tiredness
- Headache
- Mental clouding (chemo brain)
- Risk of infection (neutropenia)
- Low platelets (Thrombocytopenia)
- Low red blood cells (Anaemia)
