Drug Test Cut-off Levels for Opiates

In this article we examine the cut-off levels of urine and saliva drug tests for Opiates.

What are Opiates?

The group of natural and synthetic drugs that have a morphine like pharmacological action are known as Opiates. Primarily these drugs are designed for pain relief but they can also be abused for recreational purposes. Opiates are morphine and a variety of drugs that are structurally similar (eg, codeine, hydrocodone, hydromorphone, oxycodone).

The most commonly abused opiate is heroin (diacetylmorphine). Heroin is a a synthetic opiate that is made from morphine

What are Drug Test Cut-Off Levels?

One of the most important aspects of a drug test is the cut-off level. The cut-off level is a predetermined concentration above which the test is positive, below the cut-off, the test is negative.

The reason for a cut-off is to eliminate the possibility of a positive test due to casual exposure or other factors other than drug use that could cause the subject to appear to have drugs in their system.

The concentration of a drug is measured in nanograms per millilitre, written as ng/mL. A nanogram is a billionth of a gram, so a minuscule amount. There are approximately 30 millilitres in a fluid ounce.

Establishing Cut-Off Levels

Most drug tests have cut-offs set at a level that is as low as possible, while still minimizing the potential for false positives. The cut-off allows for an optimal window for detecting the drug or drug metabolites that the test is looking for.

Drug Test Cut-off Levels for Opiates

Cut-off levels will vary depending on the specific test type. The tests most widely used for workplace testing are urine and saliva tests. The cut-off level is significantly lower for saliva tests than urine tests.

Cut-off Levels for Urine Drug Tests for Opiates

The standard cut-off for workplace urine drug tests for Opiates in the UK is typically 300 ng/mL. All of our drug test kits, including multi panel kits that test for 5 drugs, 7 drugs, and 12 drugs, all use the standard 300 ng/mL cut-off level.

Urine tests for Opiates will detect drug usage for between 3 and 5 days after the last use, depending on how much and how frequently the drug is used.

Urine tests are best suited to situations where it is important to find out if someone has recently used drugs, though they may not be currently impaired.

Cut-off Levels for Saliva Drug Tests for Opiates

As previously mentioned, drug tests using saliva samples have a lower cut-off than those using urine samples.

Drug tests that use saliva also have a much smaller window in which drugs can be detected. Saliva tests cannot detect most drugs more than about 24 hours after use.
Saliva drug tests are best suited to situations where it is important to find out if a subject has used drugs very recently, or to find out if a subject is currently impaired.

The standard cut-off for saliva drug tests for Opiates is 40 ng/mL. Our saliva drug test kits, including the 4 drug test and the 7 drug test, use this standard cut-off.

Photo Credit: Lindsay Joye on Flickr

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