A serum drug screen is a qualitative test designed to detect and identify prescription or over-the-counter drugs that are frequently found in cases of drug overdose or used with suicidal intent. This test aims to identify the presence of drugs within a specimen. Quantification of identified drugs can be performed upon client request, when available. It is important to note that this test is not intended for therapeutic drug monitoring, compliance testing, or employment-related testing, and it is not performed using chain of custody procedures.
Purpose and Scope of the Test
This test is designed to detect a broad spectrum of prescription and over-the-counter drugs. Its primary purpose is to assist physicians in managing patients presenting with apparent overdose or intoxication, or to help determine if a specific set of symptoms may be attributed to the presence of drugs. The test is intended to detect drugs with toxic effects, as well as known antidotes or active therapies that a clinician can initiate to manage these effects.
It is crucial to understand that this test is not appropriate for drugs of abuse or illicit drug testing, which includes substances such as benzodiazepines, opioids, barbiturates, cocaine, and amphetamine-type stimulants. Furthermore, certain drugs of toxic significance are not detected by this particular test. These include, but are not limited to, digoxin, lithium, many drugs of abuse or illicit drugs, some benzodiazepines, and some opioids.
Interpretation of Results
The drugs detected by this test are considered presumptive. A comprehensive list of detected drugs and their respective limits of detection can be found in the "Prescription and Over-the-Counter Drug Screening List and Limits of Detection." The interpretation of test results is guided by the pharmacology of each detected drug. A detailed discussion of each drug's pharmacology is beyond the scope of this document.
The test description may include reference intervals and additional information to aid in the interpretation of test results. When appropriate, these intervals may be based on age and sex. Unless otherwise designated, intervals are Mayo-derived.
Test Performance and Scheduling
The test is performed on specific days, and this information outlines the days by which the sample must be received at the testing laboratory to initiate the testing process. This includes any necessary specimen preparation and processing time prior to the actual test performance.
The interval for results availability, from the receipt of the sample at Mayo Clinic Laboratories to the reporting of results, takes into account standard setup days and weekends. The indicated turnaround time represents the typical duration for a result to become available.
Pricing and Access
The fee charged for performing a test is determined by several factors. Authorized users can sign in to "Test Prices" for detailed fee information. Clients without access to "Test Prices" can contact Customer Service 24 hours a day, seven days a week. Prospective clients are encouraged to contact their account representative.
Regulatory and Coding Information
This section provides information regarding the medical device classification for laboratory test kits and reagents. This test was developed and its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the U.S. Food and Drug Administration.
Guidance is provided for determining the appropriate Current Procedural Terminology (CPT) code(s) for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories' interpretation of CPT coding requirements. Additionally, guidance is offered for determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test.
International System (SI) of Unit reports are provided for a limited number of tests and apply only to results expressed in the units of measure originally reported by the performing laboratory.
Understanding Drug Testing
Drugs are chemical substances that can alter how your body and mind function. A drug test is used to detect signs of illegal drugs or certain prescription and/or over-the-counter (OTC) medicines that may be misused. The most common sample for drug testing is urine (pee), but blood, saliva (spit), hair, sweat, fingernails, or breath can also be used.
Misuse of prescription medicines, including opioids (e.g., codeine, oxycodone, morphine, fentanyl), barbiturates (e.g., phenobarbital), and benzodiazepines (e.g., alprazolam), means taking them in a way different from how your healthcare provider prescribed. This also includes using them in a way you are not supposed to. Misuse of over-the-counter medicines, such as dextromethorphan (DXM) and certain laxatives, is also a concern.
Drug tests can detect drugs taken hours to several days or more before the test. They are used to determine if a person has been using or misusing one or more drugs or prescription/OTC medicines.
Common Uses of Drug Testing
Drug testing is utilized in various contexts:
- Employment: Employers may require drug tests before hiring or as part of a drug-free workplace program to check for on-the-job drug use.
- Sports: Participation in organized sports may necessitate drug testing.
- Substance Use Disorder Treatment: Testing can be part of a treatment plan.
- Legal Evidence: Drug tests can serve as evidence in criminal investigations or motor vehicle accident cases.
- Prevention of Misuse: To prevent prescription drug misuse and detect over-the-counter (OTC) drug misuse.
You might be asked to take a drug test for a job, to participate in sports, as part of a police investigation or court case, or in a hospital emergency room if you show signs of a possible drug overdose.
Sample Collection Methods
Urine is the most common sample for drug testing. You will receive instructions on how to collect your sample. In some cases, a health care professional or another person may need to be present during sample collection.
If a blood sample is used, a healthcare professional will draw blood from a vein in your arm using a small needle. A small amount of blood will be collected into a test tube or vial. You might feel a slight sting.
For a saliva sample, a provider will use a swab to collect saliva from your mouth, either by rolling it around or holding it under your tongue for about 2 minutes until it is soaked.
A breath test may be used to detect alcohol consumption.
It is essential to inform the testing professional about any prescription drugs, over-the-counter medicines, or supplements you are taking, as these substances can potentially affect test results.
Understanding Test Results
There are no known physical risks associated with having a drug test. A positive test result indicates that one or more drugs were found in amounts suggestive of drug use or misuse. If a test result is positive, a follow-up urine test is typically performed to confirm the initial finding.
A false positive occurs when the test incorrectly indicates the presence of a drug that is not actually in the sample. The confirmatory test following a potential false positive is crucial for accuracy.
It is important to note that even if marijuana is legal in your state, employers in some states may still take action based on a positive test result due to their desire for a drug-free workplace.
Home Drug Tests
Home tests are available for many illegal and prescription drugs, offering rapid results in the comfort of your home. However, if a home test yields a positive result, a follow-up laboratory test is necessary to verify its accuracy. Always follow the instructions carefully when using at-home tests.