Renal function tests, methotrexate

Methotrexate is an antimetabolite, which is metabolised by the renal and hepatic systems and may lead to renal and hepatic toxicities. Liver and renal function tests are therefore carried out for patients who are administered the drug. Methotrexate can lead to myelosuppression and therefore full blood counts must be monitored for patients taking it. 

Monitoring Periodic monitoring for toxicity, including CBC with differential and platelet counts, and liver and renal function testing is mandatory. Periodic liver biopsies may be indicated in some situations. Monitor patients at increased risk for impaired methotrexate elimination (eg, renal dysfunction, pleural effusions, ascites) more frequently (see Precautions). 

METHOTREXATE ANTIMALARIALS -PYRIMETHAMINE t antifolate effect of methotrexate Pyrimethamine should not be used alone and is combined with sulfadoxine. Pyrimethamine and methotrexate synergistically induce folate deficiency Although the toxic effects of methotrexate are more frequent with high doses of methotrexate, it is necessary to do an FBC, liver and renal function tests before starting treatment even with low doses, repeating these tests weekly until therapy is stabilized and thereafter every 2-3 months. Patients should be advised to report symptoms such as sore throat and fever immediately, and also any gastrointestinal discomfort. A profound drop in white cell count or platelet count warrants immediate stoppage of methotrexate therapy and initiation of supportive therapy... 

METHOTREXATE CISPLATIN t methotrexate levels, with t risk of pulmonaiy toxicity Cisplatin is the most common anticancer drug associated with renal proximal and distal tubular damage. Cisplatin could significantly l renal elimination of methotrexate It would be best to start with lower doses of methotrexate. It is necessary to assess renal function prior to and during concurrent treatment until stability is achieved. Monitor clinically and with pulmonary function tests... 

These include mesalazine, metformin, NSAIDs, tetracyclines (except doxycycline and minocycline), chloramphenicol, lithium, methotrexate, chloroquine, fibrates, chlorpropamide and glibenclamide, Clinically, it is useful to measure urine output per hour or per 24 hours as a fall in urine output in the presence of adequate fluid intake often indicates or warns of some impairment of renal function. Furthermore, it is neither expensive nor time-consuming to perform a quick test for albumin, casts and red cells in the urine, and to measure pH. Creatinine clearance values are often used to determine the safe doses for several drugs (e.g. NSAIDs, ciclosporin). 

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