Millennium Labs – Prescription Drug Monitoring & Genetic Testing

Q&A Adulteration

Q: I sent a urine specimen to one of the reference labs I use to test for pain medications. Before sending the specimen, I performed a validity test for pH by dipstick in my office, which yielded a result of 7.0. The lab rejected it because when they re-measured the specimen two days later, the pH was 9.5. Why is there a difference in pH levels and why did the reference laboratory reject the specimen?

A: From the time the specimen is collected in the office to when it was tested at the laboratory, the pH may have changed considerably. Over time, a bacterium hydrolyzes the urea in the urine specimen. One of the by-products of bacterial degradation of urea is ammonia, which increases the urine pH. The reference laboratory you mentioned should not have rejected the specimen even though the pH was 9.5. (Millennium Laboratories accepts specimens up to pH 9.5.) In this case, adulteration was unlikely.

Q: My patient tested negative for all drugs, including prescribed medications. However, their specific gravity and creatinine test results were flagged as abnormally low. How should this result be interpreted?

A: Abnormally low creatinine and specific gravity levels may be indicative of a patient having adulterated their urine by diluting it with water. However, it may also be the result of ingestion of very large volumes of fluid. Recommendations; the patient should be retested and asked not to drink large volumes of fluids prior to the urine test.

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