Does this test have other names?
Cocaine drug test, toxicology screen, tox screen, substance abuse test, drug-of-abuse
What is this test?
A cocaine screen is a test done to find out whether you have used cocaine recently.
The test can be done on your urine, saliva, blood, hair, or sweat. It looks for the
presence of cocaine or one of its metabolites. These are chemicals your body makes
to process cocaine. The two most important metabolites of cocaine are benzoylecgonine
(behn-zoyl-EHK-oh-neen) and ecgonine methyl ester (EHK-oh-neen MEHTH-ihl EHS-ter).
Testing is usually done for the first of these two metabolites.
Rapid screening tests can be done in an office or clinic. The results arrive in minutes.
Because lab tests are more sensitive and reliable, positive results should always
be sent to a lab for confirmation.
Why do I need this test?
You may need this test if you:
Have (or apply for) a job that needs drug testing
Apply for insurance that needs a drug test
Have been arrested and drug testing is part of your parole
Are pulled over and are suspected of driving under the influence of drugs
These are reasons your healthcare provider might order the test:
He or she suspects you are abusing cocaine.
You are in the emergency room with symptoms that suggest drug abuse.
You are a patient at a drug treatment clinic.
What other tests might I have along with this test?
A cocaine screen is usually done as part of a wider screening for commonly used illegal
drugs. The wider drug screen usually tests for amphetamines, opioids like morphine,
methadone, and heroin, PCP (phencyclidine), and marijuana.
What do my test results mean?
Test results may vary depending on your age, gender, health history, the method used
for the test, and other things. Your test results may not mean you have a problem.
Ask your healthcare provider what your test results mean for you.
The cocaine screen results are usually reported as positive, which means cocaine or
its metabolites were found, or negative, meaning no evidence of cocaine was found
in your body. These results are based on a cutoff number that shows the concentration
of the substance found in your urine, saliva, blood, hair, or sweat. The exact cutoff
number depends on which test is used.
How is this test done?
You will probably either urinate in a cup or have saliva taken out of your mouth.
Urine is the most common sample used. A urine test can detect cocaine metabolites
for two to three days after cocaine use. In heavy users, the test may be positive
for up to two weeks after use.
One drawback is that people have found ways to cheat to get a false negative, meaning
a negative result when the result should be positive because of cocaine use. Products
promising to alter urine test results are advertised on the Internet, and cheating
usually involves adding a substance to the urine to affect the test results. To keep
people from cheating, some testers will insist on watching people while they urinate
in the cup.
If you provide a urine sample, the tester may test the sample right away. The result
will be available in minutes. If the result is positive, the tester should send a
sample to a lab for confirmation, because the rapid tests are not as accurate as a
Saliva testing is getting more popular because it's easier and less intrusive than
collecting a urine sample. Saliva is usually taken from your mouth with a special
device or deposited by you directly into a tube. It is harder to cheat on a saliva
test because the tester commonly watches you during the whole process. The saliva
test can detect cocaine or its metabolites for only about one to two days after use.
A lab can also test a sample of your blood. Your blood holds cocaine for 12 hours
and benzoylecgonine for 48 hours. But a blood test is invasive and takes more time.
Blood tests are usually done only if you are in the hospital and your healthcare provider
suspects drug abuse.
Your hair can also be tested for cocaine. Hair testing can detect cocaine for months
after use. It is a complicated process, though, and may not always be accurate. Results
can vary based on where the hair sample is taken.
Your sweat can be tested with a patch you put on your skin, but this is not a common
test. Results can vary based on where you put the patch.
Does this test pose any risks?
Having a blood test with a needle carries some risks. These include bleeding, infection,
bruising, and feeling lightheaded. When the needle pricks your arm or hand, you may
feel a slight sting or pain. Afterward, the site may be sore.
Doing a urine or saliva test doesn't pose any risks.
What might affect my test results?
A urine test can be falsely negative if the urine sample is cloudy or contains sediment.
If someone tampers with the urine sample, the test may be inaccurate. Products can
be added to urine to dilute it and affect the test results.
If you are a drug user, you may not be able to produce enough saliva for a saliva
sample. The tester may give you a piece of candy or gum to help you produce more saliva.
How do I get ready for this test?
No preparation is needed for urine, blood, hair, or sweat tests. Make sure your mouth
is clean before you provide a saliva sample. Be sure your healthcare provider knows
about all medicines, herbs, vitamins, and supplements you are taking. This includes
medicines that don't need a prescription and any illegal drugs you may use.