Limitations of test strips to check illegal drugs for dangerous substances

Use every precaution, even if you or your friends use fentanyl or xylazine test strips:Never consume alone.Consider consuming a smaller dose: start low and go slow.Don't mix opioids with alcohol or other drugs.Go to a supervised consumption site if your community has one.Carrynaloxone, which can temporarily reverse an opioid overdose. Make sure that you, and the people with you, know how to administer it.Call 9-1-1 or your local emergency help line if you think someone is having a drug overdose.Get your opioid overdose wallet card and carry it with you. Know what to do.Limitations of test strips for illegal drugsTest strips, whether they are a medical device or not, can provide false negatives. A false negative result means that the test strip did not detect a targeted drug even though the drug was present in the sample. This could lead to a false sense of security, resulting in overdose or death.There are many reasons test strips may not detect all drugs present:The test strips may only be able to detect certain substances, such as xylazine or fentanyl, and not other toxic substances that might be present, like carfentanil.Illegal drugs can be mixed unevenly with other substances, so the portion tested may not contain the same amount of the drug as that which is to be consumed.Other substances mixed in the sample could interfere with the accuracy of the test.The sample size tested may be too limited to detect a specific substance.Health Canada is working with companies of authorized products to include warnings on the packages of test strips that detect the presence of xylazine, fentanyl and/orits analogs to better inform consumers about the risks of unreliable results when using the test strips to check the illegal drugs they plan to consume.For more information:Health Canada is advising Canadians of the potential limitations when using test strips to detect fentanyl (December 13, 2017)Health Canada reminds Canadians of the limitations of fentanyl test strips being used to check street drugs before consumptionSigns of an Opioid OverdoseNaloxoneCanadian Pharmacists Association: Naloxone Made Easy (video)