What are signs of methotrexate intoxicty?

Many: Methotrexate toxicity can take many forms, from extreme mucositis, low blood counts, and kidney damage. If Methotrexate is given intrathecally (into spinal csf) as is done to treat leukemia, it can sometimes cause toxicity to the brain, which can manifest itself as seizures. Methotrexate can also affect the liver and lungs. If you are having new symptoms, talk with the prescribing doctor.