Methotrexate is a drug which must be taken as per the recommended dosage only. The first and most evident side effect of this drug is dizziness, diarrhea and nausea. These are just minor effects and can be easily avoided by consuming a heavy meal before taking the dosage of this medicine. Sometimes, the patients can also get distressed with acute diarrhea which is typically characterized by liquid bowel movements. Further, the over-dosage of this medicine can cause ulcerative stomatitis which is characterized by the formation of small ulcers on the oral mucosa. These ulcers may particularly appear on the inner walls of the cheek or any where inside the mouth.

A patient taking the medication of Methotrexate is vulnerable to catching infections like nocardiosis, pneumonia and sepsis. Patients who take this drug via intrathecal route may experience severe reactions in the central nervous system of the body. Further, skin dryness is a common side effect which may become worse if exposed to the harmful UV rays as well as hot water. In addition, if the medication is not taken as per the correct instructions, it may lead to several other disorders like anemia, neutropenia, pancytopenia, lymphoproliferative and thrombocytopenia disorders.