Naltrexone is an opioid receptor antagonist. It is chemically related to the opioid family and I'm inclined to guess that it probably would test positive for an opioid. I'm going to research this further and get back with you shortly. It should only take me about 15 minutes. I'll let you know if I'm unable to find a definite answer as well.
Back in a few,
Anthony Bray MD
Naltrexone may interfere with the enzyme detection tests for opiods. It is chemically related to oxymorphone. The potential for interference depends on the specificity of the tests and the method the test employs. You would need to consult the manufacturer of the particular test. The drug does not interfere with the more specific tests such as thinlayer chromatography, gas-liquid chromatography and high pressure chromatography looking for specific drugs such as morphine or methadone.
So, inother words the screening tests for opiods would probably test positive but if detailed confirmatory tests were done then it should not cause a false positive with these. If you are tested then the prescription for naltrexone should be listed to help you keep out of trouble.
I hope this helps. Further questions are welcome if you have any. If my answer has been helpful and to your satisfaction then please remember to press the "ACCEPT" button. Thank you and Best Regards,