| Specimen Container |
EDTA tube |
| Specimen Requirement |
Whole Blood EDTA Between 8 am to 9 am on Monday only, collect 3 mL of fresh blood from patient and despatch immediately to DPLM Client Service. Specimen is not to be collected on Tuesday to Sunday, eve of public holidays and public holidays. |
| Specimen Storage/Transport |
Keep specimen at room temperature. DO NOT send on ice or refrigerant. Despatch to KKH DPLM Client Services as soon as possible as blood must reach NUH by 12 noon. |
| Orderable as Urgent? | No |
| Testing Laboratory Location |
NUH |
| Laboratory | Mayo Medical Laboratories in Rochester |
| Contact Number |
6394 1352 |
| Day and Time Performed |
Monday only except for Public Holidays and eves of Public Holiday, between 8 to 9 am. |
| Orderable on CPOE? | No |
| Downtime Form | |
| Additional Information |
Patient preparation: Patients should abstain from the following drugs for at least 48 hours prior to TPMT testing: naproxen (Aleve), ibuprofen (Advil, Motrin), ketoprofen (Orudis), furosemide (Lasix), sulfasalazine (Azulfidine), mesalamine (Asacol), olsalazine (Dipentum), mefenamic acid (Ponstel), trimethoprim (Proloprim), methotrexate, thiazide diuretics, and benzoic acid inhibitors. This test is useful for the detection of individuals with low thiopurine methyltransferase (TPMT) activity who are at risk for excessive myelosuppression or severe hematopoietic toxicity when taking thiopurine drugs. Detection of individuals with hyperactive TPMT activity who have therapeutic resistance to thiopurine drugs and may develop hepatotoxicity if treated with these drugs. |
Last Updated - 27 May 2025
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