DRUG SCREENING LABS STAY BUSY

A common allergy pill could get a person busted on a drug test.

Medications such as ephedrine can come across as an amphetamine on a drug
screening, said Dr. Jimmy Lea, a toxicologist at Medical College of Georgia
Hospital.

"You run into trouble with that, in that there are a lot of
over-the-counter drugs that cross-react and cause false positives," he
said. "Especially this time of year, when you've got people taking allergy
medicines."

Once a rarity, drug tests are now common for many in this country.
President Reagan introduced drug testing for federal employees in 1986 when
he signed the Drug-Free Workplace Order, according to Kent Holtorf's book
Ur-ine Trouble. Private-sector employment testings were launched two years
later with the passing of the Drug-Free Workplace Act. Today, labs conduct
drug tests for several reasons, including employment screenings, probation
periods, workers' compensation or accidents. Phil Williams of Mullins
Laboratory said the lab did drug screenings in the late '80s for parents
who wanted to know whether their children were using drugs.

Labs must be extra careful to ensure that a legal substance does not
produce a positive test.

In order to guarantee that a pill or poppy seed bagel doesn't yield a
positive result, some labs administer alternate tests to confirm whether a
specific drug is being used.

They also perform tests to determine whether a specimen has been tampered
with or mixed with a chemical to mask a drug.

Generally, urine is used as a test specimen because it gives a greater
window of detection for drugs than blood or other bodily fluids. The
process also collects a sample without the use of needles.

"Most of these drugs have a very short half-life," Mr. Lea said. "Think of
the kidney as a sink. Everything you take in is going to be processed
through that sink. It comes out as urine."

Immunologic screens use antibodies to detect drugs such as cocaine,
marijuana, barbiturates, opiates, amphetamines and PCP, Mr. Williams said.

If a test comes back positive, it can be confirmed with thin-layer
chromatography or gas chromatography-mass spectroscopy, processes similar
to developing a picture.

Labs also have tests that can detect attempts to mask a drug. For example,
if for some reason the immunologic screen and the chromatography differ, a
dipstick method can be used to determine whether the sample has been
altered. Mullins Lab uses a device called AdultaCheck 4.

The AdultaCheck tests for creatinine, glutaraldehyde and nitrites and
checks the pH levels. If the creatinine level is low, someone has diluted
the urine.

The pH level might change slightly, but if it goes above a certain level,
it is not normal. There should be no sign of glutaraldehyde or nitrites
because the body doesn't produce them.

Their presence can suggest that someone used an additive to mask a drug.
Although people use such adulterants to mask their test, Mr. Williams said
there is nothing anyone can consume to cover drugs in urine.

"Anybody that I know that does drug screens checks for specific gravity and
creatinine concentration," he said. "If they're low, then that basically
tells you that the specimen wasn't adequate to assess the individual's status."