Qualitative drug screening is typically performed where the urine sample is collected. A collection cup with a series of panels adhered to the inside of the cup is normally employed. The strips (panels) on the inside of the cup are impregnated with biochemical reagents which independently respond to a particular class (up to 12 drug classes) of drugs. If a sufficient amount of drugs from a particular class of class of drugs is present the indicator on the strip reacts positively. There is no numerical value with this screen just a positive or negative result for a particular class of drug, not the specific drug. For instance: A patient may test positive for Benzodiazepines, however there is no indication as to which Benzo the patient is taking.
Semi-Quantitative drug screening is an alternative to qualitative drug screening. They both cannot be employed and billed jointly. A plain plastic cup is used to collect the urine and a piece of equipment called an auto-analyzer is used to screen the urine for drug classes which may or may not be present. The auto-analyzer will give a numerical result (thus semi-quantitative) dependent upon the summed concentration of drugs within a certain class. Although a more sensitive screening device than a cup, the specific drug or drugs that contribute to the positive response cannot be identified through the Semi-Quantitative Urine Drug Screen.
Note: Both Qualitative and Semi-Quantitative tests can produce false positives and false negatives due to different factors. Quantitative (Confirmation) testing provides a definitive answer to questions of drug usage.
Quantitative testing is used to further define the results of a drug screening, either by cup or analyzer. It provides definitive proof of the presence or absence of specific drugs in a urine sample. Quantitative testing requires a complex mass spectrometer machine (either gas or liquid) which has to be calibrated for whatever drug is being tested. It will not detect drugs it is not calibrated for, even if they are present. A numerical value or cutoff value is determined using this type of testing.
A cut-off value is the decision point which segregates a test result as being positive or negative. Cut-off value for a test is given a defined drug concentration value chosen to minimize the number of false positives. A negative sample could still have a drug concentration below the defined cut-off value for that drug. Although cut-off values may differ from lab to lab they are all very close to agreed industry standards. If a drug or a metabolite of a drug, has a cut-off value of 50ng/ml (nanograms per milliliter) any value of 50 or greater is a positive test. Any value below 50 is considered negative
ILDP uses a LC-MS machine to perform confirmation/quantitative testing. Of the two commonly used mass spectrometry methods, LC-MS offers several advantages over GC-MS (Mikel et al., 2010). These include the ability to discriminate a larger number of drugs in each test run, the very small amount of urine specimen required (as little as 23 microliters, or one drop), and the ability to use a sample that is neither derivatized nor extracted.
LC or Liquid Chromatography is a form of chromatography. In chromatography a sample is carried through a column and the movement of the sample through this column causes the compound (drug) constituents to separate. In LC the sample is slightly heated causing it to volatilize. Note that chromatography of any kind is simply a separation technique. Usually a chromatographic (or separation) technique is combined with a measurement technique.
MS or Mass spectrometry is a technique of measurement. This analytic approach uses isotope dilution to quantify the amount of drug in the urine specimen; isotope dilution is considered the gold standard for determining how much of a drug is in a specimen (quantitation). When the sample is separated by LC, a specific compound species will come through the column. In MS the compound is hit with a force causing the molecule to split apart in a predictable way. The pieces of this molecule are then measured as they hit a detector. These pieces appear as peaks on a graph or chromatogram. These peaks are then checked against a library of known compounds (drugs) to find a match. Once a match is found, the compound (drug) is identified. This is a quantitative method which means the amount of the compound (drug) in the sample can be determined by the peak heights or intensities.
Drug Metabolism has a direct affect on how long a drug is detectable in the body. Drug Metabolism is the biochemical modification of pharmaceutical substances (drugs) by living organisms. In other words it is the body's way of changing a drug into a form that can be used and eliminated. Drug metabolism often converts lipophilic (fat loving) chemical compounds into more readily excreted hydrophilic (water loving) products. Typically this involves making the drug more water soluble so it can be excreted by the kidneys in the urine. The half-life of a drug is a measure of the rate of metabolism of the drug. When a drug is metabolized it is actually changed into a different compound. The compound that a drug is changed into (the drug's 'metabolite') may also be a drug on its own and be active in the body, but not always. Typically drug metabolites are not active or as active as the parent drug, but this is not always the case. A pro-drug, such as codeine or tramadol, must be metabolized into a more active form (morphine, o-desmethyltramadol) in order for the full drug effects to be experienced. In such a case, it is the drug’s metabolite that is responsible for the for the main effects of the drug.
ILDP LC-MS drug tests are designed to detect both the parent drug and common metabolites of the drug. This means that even after the parent drug itself is out of the system, if its metabolites remain (even if the metabolites themselves are not active) the metabolites may trigger a positive on a drug test. When a sample is taken for confirmation testing, the confirmation test will differentiate between parent drug and metabolite. Due to the fact that drug tests detect metabolites, half-life is not a measure of the length of time a drug is detectable. As far as drug testing is concerned a positive for a drug metabolite is the same as a positive for the parent drug.
Some drugs are designed to undergo extensive metabolism and may have several metabolic products. A perfect example of this is the benzodiazepine, diazepam (Valium). Diazepam is known as a long-acting benzodiazepine. It is long acting because its metabolites are also active benzodiazepines (nordiazepam, temazepam, and oxazepam are all active metabolic products of diazepam). The extensive metabolism of diazepam explains why a single dose of diazepam can cause drug test positives for up to 10 days. Diazepam is also a great example of a drug that is highly lipid-soluble. Chronic dosing of diazepam will result in a buildup of the drug in fat tissue further extending the detection time well beyond 10 days.
Historically, point of care (POC) urine drug testing (screening) has been used for pre-employment, workplace monitoring, and law enforcement applications and only identify a class of drugs. Urine drug testing achieved by point-of-care (POC) devices, are usually based on immunoassay technologies, which not only have elevated cut-offs, but also are unable to identify specific drugs within a class. An individual gives a urine sample and the results are immediately read off the cup or with a dip stick. In these instances, administrators are looking for negative test results to verify that individuals are not misusing narcotics or other illicit drugs. Traditional cut-off levels (normally as high as 300 or 2,000ng/mL for opiates) are well suited for detecting drug concentrations typically associated with abuse. However, POC tests are known to produce false positives and traditional cut-off levels are not effective in providing accurate assessments of patient compliance.
ILDP employs state-of-the-art confirmation technology using a LCMS, that provides a unique “chemical fingerprint” for the drug and all of the drug’s metabolites in question, enabling positive identification and quantitation at very low levels with great accuracy. Just as the term suggests the LCMS that we use “confirms” the accuracy or inaccuracy of the POC screen.
Very little. It is important if you do a cup test, there is enough urine to reach the strips on the cup so you get an accurate screen. If sending to lab for confirmation or for the lab to perform a screen with an analyzer, a quantity of 10 ml is all that is needed. The same as filling a 10cc syringe.
For urine specimens confirmed at ILDP, the standard turnaround time is 48 to 72 hours after receipt of the urine sample. Request of additional tests not included in our routine testing may extend turnaround time to 3-5 business days.
Yes, however, the concept of a false positive is limited to different factors, and that is why all POC screening tests that are positive should be confirmed in the lab. ILDP's laboratory reports results based on confirmation testing by LC/MS. This type of testing (Mass Spectrometry) provides what is effectively a “chemical fingerprint” pattern for each drug. As such, the possibility of a false positive result is eliminated.
Reason 1: Patient is taking a prescription medication known to cross react with the cup and results in THC positive (e.g. Protonix). Reason 2: THC metabolizes into several metabolites between which the cup cannot differentiate, meaning that the cup response is an accumulative result. ILDP laboratory analysis detects only one of the many cross-reacting compounds, carboxy-THC, which may be at a concentration below the reporting limit
This scenario is only possible when relying on point-of-care or “instant” immunoassay testing methods, such as urine cups or dipsticks. Such devices recognize drug classes based on their “chemical shape” and most commonly change color when that shape is recognized. If other drugs with similar chemical shapes are present in the sample, this can result in a "false positive." Sustiva, Protonix, and other proton pump inhibitors can cause individuals to test positive for THC on certain instant devices, while common antibiotics such as amoxicillin can cause a person to test positive for cocaine.
While these drugs can generate false-positive results on instant testing devices, they will not generate a positive result at the ILDP laboratory. Because of our sophisticated instrumentation, laboratory testing is far more selective and looks for what is effectively a "chemical fingerprint" of each drug tested. Therefore, a drug will only test positive if the specific drug, or a metabolite of a specific drug of interest, is actually present.
Morphine is not known to metabolize to codeine. Trace urinary codeine concentrations may be present in individuals on high doses of morphine due to codeine impurity in the morphine tablet. The presence of this codeine impurity is well documented and can account for low concentrations of codeine detected in the urine from patients who have been prescribed relatively high doses of morphine for extended periods of time. When the morphine concentration is low, this trace codeine impurity is undetectable; however, at high morphine concentrations, codeine may increase slightly above the minimum detection limit. This is another example of why patients should be retested randomly, when they return for another visit.
There are many variables associated with urine drug levels. Caution should be used when interpreting quantitative levels. A few common reasons for the differences in urine levels for two patients on the same dose of a drug include urine pH, co-administration of other drugs, hydration level, the rate at which their body metabolizes the drug, body type, cardiac output, timing between dose and specimen collection, and possibly patient non-compliance.
It will depend largely on three factors: Dose, frequency of dose, and metabolism/excretion capabilities. If the patient is prescribed oxycodone TID or QID, and they are taking it as prescribed, then the urine should still test positive for the drug. If the patient is only prescribed single daily doses and they are capable of rapid metabolism/excretion, then the result may be negative due to screening cutoffs. The patient may also test positive for oxymorphone due to the fact the detection window in the urine for this metabolite is longer than the parent drug.
Hydromorphone is a minor metabolite of Morphine. Current research lists the ratio of Hydromorphone to Morphine as .2-2.2%. As a minor metabolite of Morphine, Hydromorphone will only be seen if high concentrations of Morphine are present. The presence of hydromorphone on a test of a patient that is taking Morphine does not necessarily mean you are seeing the metabolite of morphine, as Hydromorphone is more commonly seen as a metabolite of Hydrocodone and is also taken as a parent drug. Many factors affect drug testing results and if clinicians have any questions regarding results, they should always contact the lab for verification.
No. The LCMS report indicated positive for oxazepam, not Serax. The LCMS does not give false positives as it is quantitative. Oxazepam is a terminal metabolite for Nordiazepam, Diazepam and Temazepam. The presence of oxazepam and no other drugs could indicate the use of Serax, or it could indicate recent use of another benzodiazepine that was discontinued long enough ago that only oxazepam remains. Again, this is a patient that you may consider retesting randomly on another visit.
Concentrations of methadone and its metabolite, EDDP, vary widely and depend on many factors such as metabolism/excretion rates, dose and dose frequency, and urine pH. Compliance cannot be determined solely from urinary methadone/metabolite concentrations. Retesting this patient will help you determine possibilities.
Not necessarily. Clinical trials indicate that the ratio of oxymorphone to oxycodone can vary from 0-184 percent and that there is no direct correlation between the dose and the resulting ratio. Oxymorphone also has a slightly longer detection window in the urine than oxycodone, meaning that oxymorphone may still be detectable following complete excretion of any oxycodone.
It is possible they are taking it. Low doses of benzodiazepines (especially alprazolam and lorazepam) can sometimes screen below the cutoff and therefore be reported as negative. If your client provides this information and you wish to determine if there is a small amount of drug in the urine, you can order a confirmation test and we can utilize the lower detection limits if you request us to do so.
Individuals who ingest poppy seeds may test positive for low levels of morphine — codeine and thebaine are present at significantly lower levels in the poppy seeds and usually go undetected in the urine. This is dependent upon the extent of ingestion and the timing between ingestion and specimen collection.
No, Oxycodone is not known to metabolize to hydrocodone and maybe they are using hydrocodone. Similar to the presence of codeine as an impurity in pharmaceutical-grade morphine, the same phenomena can be used to explain the presence of hydrocodone in the urine of patients who are prescribed high doses of oxycodone for extended periods of time. ILDP has tested various oxycodone formulations in which low levels of hydrocodone were detected. This does not preclude the possibility of hydrocodone being an abnormal and unexpected metabolite; however, it provides an explanation for the positive result. In these cases, hydrocodone concentrations are typically fewer than 100 ng/mL, its metabolite hydromorphone is absent, and high concentrations of oxycodone are present. Any patient that tests positive for something they are not prescribed should be randomly retested on another visit.
No. Adderall is a formulation containing amphetamine – not methamphetamine. Adderall use will cause a patient to test positive for amphetamine but not methamphetamine. Amphetamine does not metabolize to methamphetamine.
Possibly on the POC, but not on confirmation. Phentermine (Adipex) is a member of the same family of drugs as amphetamines; however, it DOES NOT cross react with most point-of-care or "instant" testing devices, and it is easily distinguished from amphetamine and methamphetamine during confirmation analysis. Mass spectrometry provides a chemical fingerprint for amphetamine and methamphetamine, which is independent of those obtained for phentermine.
No it does not. Phentermine is not an amphetamine and it should not test positive for amphetamine. POCT do not test for Phentermine. The most accurate test for Phentermine is a blood test, however ILDP does now do a urine test for Phentermine.
This is a great question and one of the major reasons you should always confirm positive screening tests prior to making clinical decisions regarding a patient’s health. Methamphetamine and amphetamine belong to a group of structurally related drugs called sympathomemetic amines (SMAs) which are central nervous system stimulants. The immunoassay test is sensitive to drug groups, as opposed to specific drugs. If other SMAs are present in the urine, such as ephedrine or pseudoephedrine, these compounds could cause a false positive. Following is a list of several (but not all) prescription and OTC drugs that produce a false-positive for methamphetamine on an immunoassay analyzer. These drugs will NOT test positive for methamphetamine or amphetamine when tested with an LCMS: Ephedrine, Fenfluramine, Phenmetrazine, Bupropion, Pseudoephedrine (Sudafed), Phenylpropanolamine (PPA), Thorzine (Chlorpromazine), Methylphenidate (Ritalin), Phentermine, Propranolol, MDMA (Ecstasy), Mephentermine, Mahuang Tea (or tea made from plants belonging to the ephedra family).
As a lab we cannot give out medical advice, however, we do have an obligation to maintain high compliance standards. As we have stated before if a provider has appropriate medical necessity they can order any test without fear of overtesting as long as they document medical necessity. Most clinics who do drug or alcohol rehab will order alcohol testing done. If a clinic has patients on opioids, or is planning to start a patient on opioids, that clinic might order alcohol testing done on those patients only. It is important you understand what results you are getting when you do an alcohol screening verses a confirmation and what plan you have in place once you receive the results. An immunoassay screening will alert you to the presence of Ethanol if the patient has it in their urine at the time of the test. It is important to note that Ethanol is typically only detectable in the urine for three to four hours after drinking. It is just as important to note that a patient with a high sugar content in the bladder can produce a “false-positive” test for Ethanol. Once alcohol is metabolized in the liver it produces two distinguishable metabolites: Ethyl Glucuronide (EtG) and Ethyl Sulfate (EtS) which can be confirmed with the LCMS if they are present. ILDP only tests for EtG which can be detected up to four days after the patient had their last drink of alcohol.
If a patient is taking a parent drug as prescribed, such as Buprenorphine, the levels at the lab on both the parent drug and the metabolites should both read above the cutoff levels but not outrageously high. In this case it is likely the patient has not been taking the Buprenorphine as prescribed due to the below cutoff levels of the metabolite and just as likely they took the parent drug just prior to the office visit in an attempt to pass the drug test, or dropped Buprenorphine directly in the urine cup. This is a patient that might need random drug testing.
First, testing for Ethanol alone is done on a screening analyzer. Ethanol (Alcohol) is the most abused drug worldwide. Due to the way the liver oxidizes ethanol, it must be measured in a relatively short time (less than 12 hours) post consumption in order for it to be detected. If you only want to know if your patient consumed alcohol within 12 hours prior to their drug test you do not need to confirm EtG or EtS. Acute alcohol biomarker, such as EtG(Ethyl Glucuronide) is able to be detected even if no alcohol is present within the body and generally if it is present on the confirmation test, the patient has consumed alcohol within 2-3 days prior to their drug test. Thus if Ethanol is negative EtG can be positive.
At ILDP the creatinine value in a urine sample should fall between 20-350mg/dl to be considered normal. If the value is below 20mg/dl we suspect that the sample has been diluted. This can be done by adding water to the urine sample, by drinking excessive amounts of water or by taking a diruretic. However, this does not necessarily mean the confirmation should not be done. If a drug is above the cutoff level on the LCMS, in a diluted sample, there is no question that drug was positive. (If the creatinine was normal in that sample there is a high likelihood the levels of the positive drug would be very high). However, if the sample was negative, for any drugs you might have suspected should be positive, the patient would have to be retested due to the dilution.
POCT cups test for a class of drugs and not the specific drug. All postive tests should be confirmed in order to ensure the patient is taking the drug prescribed. In this case the patient could be selling (diversion) the Xanax you prescribe and taking his relatives Lorazepam (Ativan) to pass the drug test. The POCT test was positive for Benzodiazepines, not Xanax.