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. 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.
Q: Why is ARK Laboratory’s ISO compliance important to me?
A: The International Organization for Standardization (ISO) establishes strict quality-assurance standards to guarantee consistently high-quality results. Organizations certified under ISO have been inspected to ensure that all company processes and practices meet and maintain the quality of output. At ARK Laboratory, we believe that meeting these standards is the best way to demonstrate our commitment to quality in all of our services.
Q: Why is the CLIA certification important?
A: The Centers for Medicare & Medicaid Services (CMS) regulates all laboratory testing (except research) performed on humans in the U.S. through the Clinical Laboratory Improvement Amendments (CLIA). The purpose of CLIA is to set minimum standards for all laboratories to follow and to determine if laboratories are achieving those standards. Any person or facility that performs laboratory tests on human specimens for the purpose of diagnosis and/or treatment is required by federal law to have a CLIA certificate.
Note: Although all clinical laboratories must be properly certified to receive Medicare or Medicaid payments, CLIA has no direct Medicare or Medicaid program responsibilities.
Q. How accurate are my test results?
A: Laboratory testing results are accurate and reliable. The identification of individual drugs at ARK Laboratory is achieved using a highly selective methodology called mass spectrometry (MS), which allows the laboratory to make unequivocal identifications. For this reason, all urine specimens should be submitted to our laboratory for testing, as instant devices such as urine cups or dipsticks do not offer this level of selectivity or accuracy.
Q: How are samples sent to your lab?
A: We use UPS for all of your shipping needs. No matter where you are in the country, we can receive your sample the next day. In addition, we will provide you with specimen-collection kits that come pre-addressed and ready to ship back to us.
Q: Who supplies the collection kits?
A: ARK Laboratory supplies everything that you need to do your testing, at no cost to you. If you have never placed an order with ARK Laboratory, contact a member of our sales team or Client Services at 888-392-6042 to get started.
Q: What are common sample turnaround times?
A: The following are common sample turnaround times for ARK Laboratory:
Urine: 2 business days*
Oral Fluid: 3 business days*
* Request of additional tests not included in the standard panel may extend turnaround time to 3-5 business days.
Q. What is involved in confirmation testing?
A. Confirmation analysis comprises chromatographic separation and mass spectrometry identification to detect and verify the presence of drugs in a specimen. Confirmatory testing is performed utilizing LC/MS, and LC/MS/MS methodologies and encompasses additional steps before and after the actual analysis. These steps include chemical extraction, which is performed prior to analysis in order to remove any interfering substances, data review, and data certification. ARK Laboratory’s confirmation process ensures that the results we deliver are accurate and precise every time.
Q: How do I get my reports?
A: For your convenience, reports can be viewed online, faxed, and mailed. If you don’t have a username and password for viewing reports online, contact our Client Services Department at 888-392-6042 or firstname.lastname@example.org to obtain a registration form.
Q: What if I have questions about my results?
A: Our full-time toxicologists and chief medical officer are always willing to assist you with the interpretation of results. Simply call Client Services at 888-392-6042. One of our representatives will connect you with an available expert. You may also e-mail questions to email@example.com.
Q: I don’t see the test I need. Can you still help me?
A: ARK Laboratory is a full-service reference lab. If you have specific needs or are interested in having a test created to meet your specific needs, please contact your sales representative. We will work to satisfy your request in a professional, timely manner.
Q: When reviewing a lab report, what does “Canceled: due to interference” mean?
A: Interference is an unknown signal that prevents accurate identification of drugs during the confirmation analysis. Its origin cannot be determined, but it may be an endogenous compound (a naturally occurring compound within the body), a prescription medication, or something added to the specimen after collection. In instances where a definite positive or negative result cannot be determined for a drug, the test is conducted a second time. After the second attempt, if the drug in question still cannot be accurately determined, the test for that drug is canceled.
Q. What does a negative result mean? Did the donor have anything present in their sample at all?
A: A negative result does not necessarily mean there is zero trace of a drug in a given sample. Rather, it indicates that the drug was not detected above the pre-determined cut-off concentration. For example, a cut-off of 300 ng/mL for benzodiazepines means that the combined total of cross-reacting benzodiazepines in the specimen must be above 300 ng/mL to register on the test and produce a positive result. Specimens that contain a combined total benzodiazepine concentration of fewer than 300 ng/mL will register on the test as negative. Therefore, in some cases, low concentrations may be present, but a negative result shows up on the report and is still considered to be an accurate test result.
Q. How do urine alcohol levels compare to blood alcohol levels?
A: Ethanol (drinking alcohol) may be detected in blood and urine after consumption of alcoholic beverages. Blood and urine ethanol concentrations may be very different, depending on the time between ethanol consumption and specimen collection and frequency of urination. The ethanol concentration will often be higher in urine than in blood. In some cases, urine ethanol may be highly positive and the blood completely negative. Therefore, urine ethanol cannot be used to estimate a blood ethanol concentration.
Q. Is there anything that can be used to “cheat” a urine test?
A: There are two common ways that users attempt to “cheat” a urine drug test: modify their urine sample with chemicals or drink large amounts of water prior to testing in order to dilute their sample. Many products are available on the Internet claiming to enable a person to produce a negative test result after drug use if that product is added to a urine sample. Most of these products contain strong chemicals known as oxidants, which are capable of modifying the chemical structure of a drug. ARK Laboratory tests every urine sample for the presence of oxidants to identify potential adulteration.
Dilute specimens are also easily identified at ARK Laboratory by measuring the concentration of creatinine in each sample. Individuals who consume large quantities of water prior to a test in an attempt to dilute their sample will often have abnormally low levels of creatinine. Validation tests such as those described above are performed to identify individuals who are adulterating their urine specimen in this manner.
Q. Drug screening implies that I don’t trust my patients. How do I get around this?
A: Self-reporting of drugs has limited validity, and monitoring behavior alone can fail to detect problems revealed by UDTs. Creating a UDT policy in advance and applying it consistently to all patients on opioids may help de-stigmatize the testing. Inform your patient that drug testing is a routine procedure for all patients starting or maintained on opioid therapy and it is an important tool for monitoring the safety of opioid therapy. Possible language for explaining to patients include:
“Ensures my capacity to provide treatment for your pain while balancing the need for safety.”
“Provide critical information needed to assess the success of your therapy.”
“Prescription medications are a common form of treatment for chronic pain. However, each person reacts differently to them. UDT enables us to identify individual risks related to your medications and avoid problems.”
“Our clinic uses ‘universal precautions’ in opioid prescribing, which includes UDT. This is the same as wearing gloves on all patients when drawing blood.”
Q. Can I tell whether my patient has taken the dose of opioid(s) I prescribed?
A: No. It is very difficult to correlate urine drug concentration with a patient’s dose. UDT can detect the parent drug and/or its metabolite(s) and demonstrate recent use of prescribed drugs and illegal substances. However, it CANNOT determine the amount of drug used and when the last dose was taken, or can it identify the source of the drug.
Q. My patient says he is a “high metabolizer” and that is why the expected drug is not found in his urine. Is this possible?
A: A small percentage of persons are ultra-rapid metabolizers. They metabolize specific drugs more rapidly than typical patients. It would be rare to take an opioid as prescribed and not be detected in their urine.
Q. How do I deal with marijuana?
A: This a complex issue. Marijuana is currently classified as a Schedule 1 drug by the DEA. For that reason, many providers will not prescribe opioids to patients using cannabis. Other providers reference State ‘Medical Marijuana Use’ laws and feel comfortable prescribing opioids to cannabis users. Some providers adopt a “don’t ask, don’t tell” policy, and request the lab to remove marijuana from the UDT so that positive results are not seen. Do your homework and create an office policy. Then disclose this policy to your patients.
Q. Would short-acting opioids show up in UDT?
A: Urine testing typically has a 1-3 day window of detection for most drugs depending on dose and individual differences in drug metabolism. Short-acting opioids can be detected if the lab removes the cut-off concentration so that the presence of lower concentrations is detected. If the laboratory uses LC/MS, then it will have a lower limited of detection (LOD) with less interference.
Q. Why confirm results?
A: Immunoassays used in drug screening can cross-react with other drugs and vary in sensitivity and specificity. Thus, confirmation with a more accurate method may be required for clinical decision-making. Confirmatory drug testing (LC/MS or GS/MS) of the original specimen is recommended for unexpected results, or in cases where patients are known to be high risk. However, on occasion, even confirmatory testing requires expert assistance for interpretation. Consider consultation with the lab before discussing/confronting the patient with unexpected test results and discontinuing opioid therapy.
Q. Should I use temperate and adulteration strips?
A: It depends. Drug testing for clinical compliance, unlike employment testing, does not require a strict “chain-of-custody”. However, it tampering is a concern, the specimen should be monitored for temperature and/or adulterants. Normal human urine should have a temperature between 90oF – 100 oF, pH between 4.5 – 8.5, and creatinine >20 mg/dL. Be aware that there are multiple websites and devices devoted to getting a “clean” urine drug screen.
Q. Should I perform a drug screen on every visit to patients using opioids for chronic pain?
A: No. Random screening based on the frequency recommended in the guideline should suffice for most patients. Those patients who you feel require drug screening on every visit, are perhaps not candidates for chronic opioid therapy.