NOTE:
Administration of L-dopa may falsely increase vanillylmandelic acid (VMA) results. Patients receiving L-dopa should stop taking it for 24 hours before and during the collection.
All patients receiving L-dopa should be identified to the laboratory when VMA and homovanillic acid (HVA) tests are ordered.
Bactrim may interfere with detection of the analyte. All patients taking Bactrim should be identified to the laboratory when VMA and HVA tests are ordered.
Collection Instructions:
1. Collect a random urine specimen.
2. pH adjustment not necessary if specimen will arrive at testing lab (Mayo Medical Laboratories) within 6 days of collection.
3. If specimen will not arrive at testing lab within 6 days from collection, adjust the random urine pH to a level between 1 and 5 by adding 50% acetic acid dropwise and checking the (Special Chemistry department staff will adjust pH prior to sending to Mayo)
pH. (Special Chemistry department staff will adjust pH prior to sending to Mayo)
Additional Information:
1. Patient's age is required.
2. Administration of L-dopa may falsely increase vanillylmandelic acid results; it should be discontinued 24 hours prior to and during collection of specimen.