toxic effects
Last reviewed 01/2018
Antimetabolite treatment may cause a wide range of toxic side effects. Some eg myelosuppression, are related to drug dose and duration of treatment. Most antimetabolites are not administered on a daily basis, The exceptions are mercaptopurine and its precursor azathioprine.
Some important pharmacological considerations must be considered when administering antimetabolites.
For example, pre-existing renal damage or the presence of malignant effusions can increase the toxicity of methotrexate. Also the use of non-steroidal and anti-inflammatory drugs may delay methotrexate excretion and thereby increase its toxic effects.
For example, the allopurinol treatment greatly potentiates azathioprine and mercaptopurine action by blocking catabolism of these drugs.