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HelpTest Code MPHNU Methylphenidate and Metabolite, Random, Urine
Reporting Name
Methylphenidate and Metabolite, UPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Useful For
Monitoring urine methylphenidate and ritalinic acid concentrations to assess compliance in patients
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Additional Testing Requirements
If urine creatinine is required or adulteration of the sample is suspected, also order ADULT / Adulterants Survey, Random, Urine. For more information, see ADULT / Adulterants Survey, Random, Urine.
Specimen Required
Supplies: Sarstedt Aliquot Tube 5 mL (T914)
Collection Container/Tube: Plastic urine container
Submission Container/Tube: Plastic, 5-mL tube
Specimen Volume: 5 mL
Collection Instructions:
1. Collect a random urine specimen.
2. No preservative.
Additional Information:
1. No specimen substitutions.
2. STAT requests are not accepted for this test.
3. Submitting less than 1 mL will compromise the ability to perform all necessary testing.
Specimen Type
UrineSpecimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 10 days | |
| Frozen | 28 days |
Reject Due To
| Gross hemolysis | OK |
| Gross icterus | OK |
Reference Values
Negative
Cutoff concentrations by liquid chromatography tandem mass spectrometry:
Methylphenidate: 10 ng/mL
Ritalinic Acid: 50 ng/mL
Interpretation
Methylphenidate (MPH) has an oral bioavailability of 22% to 100% with peak concentrations occurring around 2 hours for instant release and approximately 5 to 6 hours for extended-release formulations. The half-life of MPH is 2 to 4 hours. MPH is extensively metabolized to ritalinic acid, which is an inactive metabolite. The half-life of ritalinic acid is about 3 to 4 hours. Only small quantities (<1%) of unchanged MPH appear in the urine as most of the dose (60%-86%) is excreted in the urine as ritalinic acid. The presence of MPH or ritalinic acid in the urine indicates the patient has taken MPH in the past 1 to 2 days.
Day(s) Performed
Monday, Wednesday, Friday
Report Available
2 to 4 daysTest Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
80360
G0480 (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| MPHNU | Methylphenidate and Metabolite, U | 104676-2 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 608882 | Methylphenidate by LC-MS/MS | 20548-4 |
| 608883 | Ritalinic Acid by LC-MS/MS | 72790-9 |
| 608884 | Methylphenidate Interpretation | 69050-3 |
Forms
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.