Methotrexate causes

Methotrexate causes embryotoxicity, abortion, and fetal defects in humans. Benefits should be weighed against the potential risks before using Methotrexate alone or in combination with other drugs, especially in pediatric patients or young adults. However, there have been instances of malignant lymphoma arising during treatment with low-dose oral Methotrexate, which have regressed completely following withdrawal of Methotrexate, without requiring active anti-lymphoma treatment. Non-Hodgkin's lymphoma and other tumors have been reported in patients receiving low-dose oral Methotrexate. Although there is evidence that Methotrexate causes chromosomal damage to animal somatic cells and human bone marrow cells, the clinical significance remains uncertain. Methotrexate has been evaluated in a number of animal studies for carcinogenic potential with inconclusive results. No controlled human data exist regarding the risk of neoplasia with Methotrexate. Trimethoprim/sulfamethoxazole has been reported rarely to increase bone marrow suppression in patients receiving Methotrexate, probably by an additive antifolate effect. Certain side effects such as mouth sores may be reduced by folate supplementation with Methotrexate. Methotrexate may decrease the clearance of theophylline; theophylline levels should be monitored when used concurrently with Methotrexate.