Pediatricians play a critical role in detecting, dissuading, delaying, and reducing drug abuse by children. That’s why these specialists need to understand and have the capability to effectively utilize the tools and strategies to carry out these actions. However, testing for drugs of abuse is a complicated task which comprises several laboratory tests. Also, studies have shown that pediatricians rarely know how to order these tests and properly interpret the results, which can have serious implications for their young patients.
In view of the many challenges involved, the American Academy of Pediatrics (AAP) recently published a clinical report entitled ‘Testing for Drugs of Abuse in Children and Adolescents’ to provide pediatricians and other clinicians with guidance on the efficacy and efficient use of drug testing as well as the sources of errors. While this document targets pediatricians, the lead author, who is a pediatrician herself, expresses the hope that it would also help laboratories understand how they can help these specialists interpret drug tests better.
Some of the main points made in this report are:
- Certified testing – Practices and laboratories should only conduct tests for which they are certified by the Clinical Laboratory Improvement Amendments (CLIA).
- Consequences of testing – Before sending out a test, pediatricians should consider how they will manage it. Situations in which drug abuse testing is justified are emergent circumstances, such as after a suicide attempt or an accident, to assess adolescent behavioral problems, suspected drug use, or as part of a substance abuse treatment program. The AAP does not support involuntary drug testing, school-based drug testing and home-based testing.
- Constraints of immunoassay testing – Though widely used, urine tests have limitations. They are susceptible to cross-reactions which limit their specificity. Urine immunoassays can lead to false-positive or false-negative results especially if the patient is on prescription medications.
- Clinical context – This is an important consideration in drug testing. Patients taking a medication for a particular medical condition may test positive for a drug. For instance, intake of amphetamine and dextroamphetamine for attention deficit hyperactivity disorder will test positive for amphetamines, though this is a false-positive as far as drug abuse is concerned.
- Lab’s cutoff – Illicit use of drugs cannot be determined by negative screening results. Drug use can be missed in the following situations
– the samples are adulterated
– the lab’s cutoff is too high
– the patient has used a designer drug or some other compound that is not detected by the lab’s standard test panel
According to the authors, the difficulties faced by pediatricians in interpreting drug test results can be resolved to a great extent if they collaborate with laboratories. Open interaction with laboratorians will help physicians understand the limitations of the testing, what information the test provides, and how it can be used, all of which will promote better patient care. Moreover, as one expert points out, proper interpretation of the drug test is important as the pediatrician’s decision can impact the youth’s future.
On their part, laboratories need to evaluate their testing procedures to ensure better adolescent-specific cutoffs and panels that test for commonly abused substances. Using high quality lab equipment including analyzers and ready-to-use assays for drugs of abuse is also critical for faster diagnosis and treatment decisions.