Methotrexate
| Methotrexate | |
| MTX | |
| Serum Gel (Brown top). Upon arrival in the laboratory the sample is centrifuged and the serum/plasma stored refrigerated prior to referral. | |
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This test is referred to another centre for analysis: Department of Clinical Chemistry Expected turnaround time: 6 weeks For same day analysis (Mon-Fri), samples must be sent to the laboratory before 7am |
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| Used in the therapeutic drug monitoring of high dose methotrexate treatment | |
| High Dose Patients: initial sample should be taken 48 hours post dose then every 24 hours until concentration <0.1 umol/L. Second result of <0.1 umol/L recommended. N.B. There are various high dose regimes, particularly in paediatric oncology, requiring quantification up to 150 umol/L and/or a frequency of 6 hours between measurements. | |
| 'Traditional' high dose regime <0.1 umol/L after 72 hours. Methotrexate results <0.2 umol/L may still be compatible with toxicity. Measurements should be repeated to confirm falling drug levels. | |
| N/A | |
| N/A |
