FDA warnings
This drug has black box warnings. These are the most serious warnings from the Food and Drug Administration (FDA). Black box warnings alert doctors and patients about drug effects that may be dangerous.
Liver problems warning: Methotrexate can cause end-stage liver disease (fibrosis and cirrhosis). Your risk increases the longer you take this drug.
Lung problems warning: Methotrexate can cause lung lesions (sores). This effect can occur at any time during your treatment and with any dosage. Stopping treatment may not cause the lesion to go away. Call your doctor right away if you have trouble breathing, shortness of breath, chest pain, or a dry cough while taking this drug.
Lymphoma warning: Methotrexate raises your risk of malignant lymphoma (a cancer of the immune system). This risk may or may not go away when you stop taking the drug.
Skin reactions warning: Methotrexate can cause skin reactions that could be fatal (cause death). They may or may not go away when you stop taking the drug. If you have certain symptoms while taking this drug, call your doctor or 911 right away. These symptoms include red, swollen, blistered, or peeling skin, rash, fever, red or irritated eyes, or sores in your mouth, throat, nose, or eyes.
Infections warning: Methotrexate can make your body less able to fight infection. People taking this drug are at increased risk of serious infections that could be life-threatening. People with an active infection should not start using methotrexate until the infection is treated.
Harmful buildup warning: Certain health problems can make your body clear this drug more slowly. This can cause the drug to build up in your body and raise your risk of side effects. If this occurs, your doctor may decrease your dose or stop your treatment. Before starting this drug, tell your doctor if you have kidney problems, ascites (fluid in your abdomen), or pleural effusion (fluid around your lungs).
Tumor lysis syndrome warning: If you have a rapidly growing tumor and take methotrexate, you’re at increased risk of tumor lysis syndrome. This condition can be fatal (cause death). Call your doctor right away if you have any symptoms of this syndrome. Symptoms include trouble passing urine, muscle weakness or cramps, upset stomach or no appetite, vomiting, loose stools, or feeling sluggish. They also include passing out, or having a fast heartbeat or a heartbeat that doesn’t feel normal.
Warning about treatments that increase side effects: Some medications and treatments can increase the side effects of methotrexate. These include radiation therapy, which raises your risk of bone or muscle damage. These also include use of nonsteroidal anti-inflammatory drugs (NSAIDs). These medications raise your risk of problems with your stomach, bowel, or bone marrow. These problems can be fatal (cause death). Examples of NSAIDs include ibuprofen and naproxen.
Pregnancy warning: Methotrexate can seriously harm or end a pregnancy. If you have psoriasis or rheumatoid arthritis and are pregnant, don’t use methotrexate at all. If you get pregnant while taking this drug, call your doctor right away. This drug can also affect sperm. Both men and women should use effective birth control during treatment.
Gastrointestinal tract warning: Methotrexate can cause severe diarrhea. It can also cause ulcerative stomatitis, an infectious disease of the mouth resulting in swollen, spongy gums, sores, and loose teeth. If these effects occur, your doctor may interrupt your treatment with this drug.