creatinine levels in drug testing

[senyax]

I am an attorney with a client who is required to drug test randomly. She has tested over 40 times, roughly once every four or five days, and has had no "positives" for any amphetamines, alcohol, THC, cocaine, opiates, barbiturates, or benzodiazepines. She has been on methadone, and, at various times, taking various anti-depressants and medications for her mental illness. (She is said to be bi-polar.) Her drug tests show creatinine levels which fluctuate wildly --- from 40.6 mg/dL to 210.6 mg/dL, and on one occasion she had a creatinine level of 19.7 mg/dL, which the lab characterized as a "dilute specimen." All the stuff I've read on line about creatinine tests measure "normal" levels as, for example, 1.2 or 2.5mg/dL. So why are her levels measured differently? Is there any reason for a drug test to test creatinine other than to try to identify urine specimens that have been diluted? Wouldn't one specimen testing at 19.7 mg/dL, in the midst of all these wildly fluctuating levels, be unlikely to be an attempt by her to dilute her specimen? What would cause such a wild fluctuation in creatinine?

[John Kenyon, CNA]

Hello -

Most common causes of creatinine elevation are kidney disease, diets high in meats and certain medications, especially some antibiotics. However, the readings you relay are so grotesquely out of range (10-50 times the high end of abnormal) that they should have been either cited as a "critical lab finding" or thrown out and repeated because, if the patient is not deathly iil, then these results are apparently lab errors.

The "dilute specimen" finding makes no sense in the contex of the other, wildly out of range readings, and even this level would be difficult to achieve via dilution to skew the test results.

The only explanation I can think of is that this lab is using some obscure or outdated scale, or is incompetent. Anyone with findings such as those of your client would normally be place on dialysis if it weren't too late already.

Wish I could be more helpful, but this really doesn't make much sense. I can only suggest the possible assignment of a different lab.

Hope this is helpful.

[ToxPro]

I wish I saw this post 8 monhts ago! :)

The original post indicated that normal urine creatinine levels are 1.2-2.5 mg/dL - this is simply not accurate - I suspect the referenced source was either mistaken or the units employed are incorrect, as they are off by a factor of 10. Normal urine creatinine levels for random urine collections are typically observed between 40-250 mg/dL, with a mean around 100 mg/dL. Variability of random urine collections may be observed between 10-350 mg/dL, depending upon the individual and circumstances.

Being an expert in the field of Forensic Urine Drug Testing for over 20 years, I can attest that this variability in urine creatinine is not uncommon. I suspect the (previous reply) CNA's confusion may lie in trying to compare a random urine draw to a 24-hour urine collection. One of the many reasons a 24-hour urine is collected in a clincial setting is to normalize urine hydration and to get a more accurate representation of the concentration of the compound being voided.

It is true that creatinine can vary due to kidney disease, diets high in meats, certain medications, as well as age, gender, and metabolism. However, rapid intake of copious amounts of fluids, particularly when the client has ingested a diuretic, can dramatically increase urine production in a state of polyuria that produces diluted samples (very low creatinine levels - less than 20 mg/dL). Conversely, a simple case of dehydration can dramatically increase urine creatinine levels 2-3 fold.

The most common technique employed to "beat" a drug test is "water-laoding" - consuming copious amounts of fluid in a short period of time within 30 minutes of a urine collection to achieve a state of polyuria. The state of polyuria typically lasts from 1-4 hours, and during that time the urine may be diluted by a factor of 5-10 or more. The desired effect is to lower the overall concentration of trace amounts of drug(s) in the urine to a level that is below the detection limit utilized by the laboratory. This is very effective method for temporarily "masking" THC (marijuana metabolite) in a casual marijuana smoker's urine.

Many commercial products exist on the market that make claims that they can "detoxify" the body to facilitate passing a drug test. These products, sold in liquid, capsule, pill, or tea bag form, typically work by the principle of dilution. They contain herbal supplements that are natural diuretics, which are to be ingested with 80-128 oz of fluids (or more!) within 60 minutes of providing a urine sample.

SAMHSA has recognised this as a potential method of subverting federally mandated drug testing, and requires creatinine be measured on all urine samples submitted for drug testing. Samples with creatinine levels below 20 mg/dL are not acceptable and reported as diluted, invalid, or substitued depending on the creatinine levels when compared to the urine density (specific gravity). It should also be noted that diluted samples may not be due to a conscious effort of subversion, and cannot be proved to be intentional.

To summarize, RANDOM urine sample creatinine variability is common. With all due respect to the previous reply by the Nursing Assistant, the suggestion that the variability in observed urine creatinine levels is due to lab error is a "red herring".