Tetrahydrocannabinol (THC)

Tetrahydrocannabinol is the main psychoactive substance found in the Cannabis plant and additionally in a variety of other plants. It is also known as THC, Δ9-THC, Δ9-tetrahydrocannabinol (delta-9-tetrahydrocannabinol), Δ1-tetrahydrocannabinol, or dronabinol. THC is more popular as marijuana. THC is detectable using the simple immunoassay strips only for one day after use if a rather small amount had been ingested.

The after use affects of THC:

THC is the primary active ingredient in marijuana. When ingested or smoked, it produces euphoric effects. Users have impairment of short-term memory and ability to learn. Also, it may cause temporary episodes of confusion, anxiety, or even high toxic fever. Long-term use with heavy doses may cause behavioral disorders. The peak effect of smoking THC occurs in 20-30 minutes and the total effect lasts for 90-120 minutes after one cigarette. Elevated levels of urinary metabolites are found within hours of exposure and remain detectable for 3-10 days after smoking. The main metabolite excreted in the urine is 11-nor-9-tetrahydrocannabinol-9-carboxylic acid.

The THC test:

The THC drug test is based on the principle of the highly specific immunochemical reactions between antigens and antibodies, which are used for the analysis of specific substances in biological fluids. The cutoff of the test is 50 ng/ml of THC as per the SAMHSA (The Substance Abuse and Mental Health Services Administration) norms.

Procedure and interpretation of the test:

The procedure of the THC test is as follows.

1. Remove the test disk from the foil packet, and place it on a flat, dry surface.

2. Holding the sample dropper above the test disk. Squeeze 2 drops of specimen into the sample well.

3. Interpret the test results at 3 to 5 minutes.

Three interpretations can be drawn from the THC test.

1. Positive
2. Negative
3. Invalid.

The interpretations can be drawn based on the instructions provided with the THC kit.The limitations:

1. The test is designed for use with unadulterated human urine only.

2. There is a possibility that factors such as technical or procedural errors, as well as other substances in the urine samples may interfere with the test and cause erroneous results.

3. Adulterants such as bleach and/or alum, in urine specimens may produce erroneous results regardless of the method of analysis. If adulteration is suspected, the test should be repeated with a new sample.

4. A positive test result does not provide any indication of the level of intoxication or urinary concentration.

5. The test results read after the time mentioned on the test kit might not be consistent with the original reading obtained with in the reading period.

6. Prolonged passive smoking of THC may also produce a positive result.