Drug
Testing
NewsHE
FACTS
Heroin, a highly addictive drug, and
poppy seeds, a pleasant and widely used cooking ingredient, derive
from the same source, the opium poppy. This has led to a widespread
belief that eating poppy seeds before a drug test is not a great
idea.
But do poppy seeds really register in urine tests as opiates?
Absolutely, experts say.
Eating a couple of bagels heavily
coated with poppy seeds can result in morphine in a person's system
for hours, leading a routine drug test to come back positive. A
subsequent test can rule out heroin, though not other opiates,
by looking for a specific metabolite, 6-acetylmorphine.
But someone who has a poppy-seed bagel
for breakfast and is tested later that day would still have far
lower levels of morphine than a person who, for example, abuses
painkillers. For that reason, the federal government recently raised
the threshold for opiates in workplace testing, to 2,000 nanograms
a milliliter from 300. Dr. Timothy P. Rohrig of the Regional Forensic
Science Center in Kansas said eating three large bagels covered
in poppy seeds could push a person over the old opiate threshold,
though probably not the new one.
If someone tests well above the 2,000
limit and "tries to explain it by saying she ate 15 bagels for
lunch, it would sound absurd," Dr. Rohrig said. But a person with
a cold who claimed to use c dra sinensis , not the American Ephedra plant)
can produce a positive urine test for amphetamine metabolites that
will also be read by the mass spec as being meth metabolites. It
is because of the combination of both l- and d- forms of ephedrine.
Things such as Ephedra nevadensis have only the non-psychoactive
form of ephedra.
If someone were to take a moderate amount of Ma Huang for a few days it is
possible that the serum titer could go high enough to be beyond the threshold
level of detection used by most labs for gas chromatograph screening.
Pseudophedrine found in OTC drugs will not test as a meth metabolite.
ANTIBIOTICS CAUSE FALSE
POSITIVES ON HEROIN TEST
NEW YORK ( Reuters Health ) - Athletes
and hopeful job applicants often hinge their careers on a clean
drug test, but the use of certain antibiotics may cause an unsuspecting
person to test positive for heroin even though they've never touched
the drug, according to study findings released Tuesday.
Researchers led by Dr. Lindsey R.
Baden of Harvard Medical School ( news - web sites ) in Boston,
Massachusetts, investigated this problem after they came across
a patient in their practice who tested positive for opiates, and
who was also taking an antibiotic called levofloxacin. The patient
was nearly kicked out from a drug treatment center because of the
result, which later proved to be false.
Opiates are a class of drugs that
include the illegal drug heroin, and several other controlled drugs
such as methadone, morphine, Demerol and codeine.
In their study, Baden and colleagues
tested 13 different types of antibiotics, including levofloxacin
and Cipro, all belonging to a class of chemicals called quinolones,
to see what effect they would have on commercial opiate tests.
The researchers diluted the antibiotics
to concentrations that would be expected to occur in urine and
then tested the antibiotic samples using five different commercial
tests to see if they would cause a positive result for opiates.
Two antibiotics, levofloxacin and
ofloxacin, caused a strong positive result on four of the five
tests.
Most of the other antibiotics also
caused a positive result on at least two or three of the five tests.
For example, Cipro, the drug given to thousands of people to fight
possible anthrax exposure, resulted in a positive test in one out
of the five tests.
To confirm these results in people,
they had six people take a standard dose of one of the two antibiotics
and collected their urine samples every 6 hours for the next 48
hours.
On one of the five tests, all three
patients taking levofloxacin tested falsely positive within 2 hours
and up to 22 hours after taking the drug. The results were similar
in patients taking ofloxacin, the investigators report in the December
26th issue of The Journal of the American Medical Association (
news - web sites ).
Baden told Reuters Health that he
suspects that the false positives result from the similar three-dimensional
structures of opiates and the antibiotics. He also pointed out
that other types of chemicals could cause a similar reaction.
According to Baden, it is possible
that people have suffered consequences of a false positive test,
because ``a positive drug test is often assumed true, while the
protestations of the person being tested are looked at as self-serving.''
Baden recommends that anyone who tests
falsely positive for opiates ask to have drug testing performed
to confirm the result.
SOURCE: The Journal of the American
Medical Association 2001;286:3115-3119
Antiobiotics
Lead to Failed Drug Tests
Tuesday December 25 5:15 PM ET NEW YORK (Reuters Health) - Athletes and hopeful
job applicants often hinge their careers on a clean drug test, but the use
of certain antibiotics may cause an unsuspecting person to test positive for
heroin even though they've never touched the drug, according to study findings
released Tuesday.
Researchers led by Dr. Lindsey R. Baden of Harvard Medical School in Boston,
Massachusetts, investigated this problem after they came across a patient in
their practice who tested positive for opiates, and who was also taking an
antibiotic called levofloxacin. The patient was nearly kicked out from a drug
treatment center because of the result, which later proved to be false.
Opiates are a class of drugs that include the illegal drug heroin, and several
other controlled drugs such as methadone, morphine, Demerol and codeine.
In their study, Baden and colleagues tested 13 different types of antibiotics,
including levofloxacin and Cipro, all belonging to a class of chemicals called
quinolones, to see what effect they would have on commercial opiate tests.
The researchers diluted the antibiotics to concentrations that would be expected
to occur in urine and then tested the antibiotic samples using five different
commercial tests to see if they would cause a positive result for opiates.
Two antibiotics, levofloxacin and ofloxacin, caused a strong positive result
on four of the five tests.
Most of the other antibiotics also caused a positive result on at least two
or three of the five tests. For example, Cipro, the drug given to thousands
of people to fight possible anthrax exposure, resulted in a positive test in
one out of the five tests.
To confirm these results in people, they had six people take a standard dose
of one of the two antibiotics and collected their urine samples every 6 hours
for the next 48 hours.
On one of the five tests, all three patients taking levofloxacin tested falsely
positive within 2 hours and up to 22 hours after taking the drug. The results
were similar in patients taking ofloxacin, the investigators report in the
December 26th issue of The Journal of the American Medical Association.
Baden told Reuters Health that he suspects that the false positives result
from the similar three-dimensional structures of opiates and the antibiotics.
He also pointed out that other types of chemicals could cause a similar reaction.
According to Baden, it is possible that people have suffered consequences of
a false positive test, because ``a positive drug test is often assumed true,
while the protestations of the person being tested are looked at as self-serving.''
Baden recommends that anyone who tests falsely positive for opiates ask to
have drug testing performed to confirm the result.
SOURCE: The Journal of the American
Medical Association 2001;286:3115-
Bladder Infection False
Positives
You've heard me speak out against
drug testing. The most basic reason - even if we get past the privacy
issues and issues about whether it has any effect on discouraging
drug use - is that many of them are just plain inaccurate. Yet,
people have lost their jobs due to false positives that turn up
in a drug screen. And incidentally, they might never find out why.
The latest example comes from the
Forensic Drug Abuse Advisor, and it concerns how one common test
can give a false positive for the hallucinogen LSD. In fact, over
an 18-month period when 1,256 urine samples were tested for drugs
from the Wyoming Reproductive Health Study Program, 39 were found
to be positive for LSD. Upon reevaluation, it was found that 38
of these were false positives.
While reanalyzing the samples, Microgenics
Corp. discovered that women with bladder infections could end up
with false positive results. The manufacturer realized this after
E. coli bacteria grew out of two of the disputed urine samples.
It turns out a false positive reading
can occur anytime a beta-galactosidase is in a sample. The problem
is, this is an enzyme found in bacteria that frequently infect
women's genitourinary tracts.
What I don't understand is why spend
all this money and time to test women of child-bearing age for
LSD when there's such a low rate of abuse of the hallucinagenic.
Such programs keep women who need help for drug problems from seeking
it for fear of retribution. (www.healthcentral.com)
Hair Testing
Hari Color Discrimination Blondes
have more fun, and they may be more likely to get away with it,
too -- that is, if their idea of fun is taking illegal drugs. Redheads,
however, are even less likely to get caught. The darker a person's
hair, the more it accumulates traces of ingested drugs, new research
shows. Since hair color is often a reflection of skin pigmentation,
the results suggest that drug tests of hair samples may have a
racial bias. However, experts said that in practice, hair differences
are just one of many factors between individuals or ethnic groups
that can influence the results of a drug test. The work was presented
at a meeting this week of the American Society for Clinical Pharmacology
and Therapeutics in Los Angeles.
Many major police departments, as
well as employers nationwide, use hair samples to test for illegal
drugs. Proponents of the tests say they are easier to take and
more secure than urine tests, which are prone to tampering. Studies
in animals and people, however, have shown that both the color
and consistency of hair may affect the concentration of chemicals
that accumulate in it.
In the latest experiment, researchers
at the University of Utah studied the affect of hair color on drug
deposition in 31 people with red, blond, brown, or black hair.
Subjects were white, Asian-American, Hispanic, and African-American.
Black hair retains more chemicals.
Each day for five days, the subjects
took oral doses of ofloxacin, a potent antibiotic, and the painkiller
codeine. The Utah scientists then cut hair samples from the participants
four to seven weeks after the drugs were given, and tested them
with a fluorescent screening technique.
Redheads accumulated the least amount
of ofloxacin in their hair, about 1.5 nanograms per milligram.
That was about 15 times less than those with black hair, the researchers
say. Blondes and people with brown hair amassed 3.5 and 6 nanograms
per milligram, respectively. The results were similar for codeine.
Matt Slawson, a research toxicologist
at the University of Utah and a co-author of the study, says the
hair differences appear to be due to higher or lower concentrations
of the pigment molecule melanin. Some drugs show an affinity for
melanin, which is present in hair and other cells in the body.
And darker hair contains a variety of melanin that is particularly
attractive to chemicals.
Slawson says the significance of his
group's finding is open to debate. If companies have a zero-tolerance
policy for drug tests, then hair-splitting over melanin is irrelevant.
If, however, employees aren't punished for having barely detectable
traces of drugs in their hair -- the possible result of inadvertent
contact, such as walking into a room where others are smoking a
joint -- then people with dark hair might be at a substantial disadvantage.
Bill Thistle, general counsel for the Boston-based employee drug
testing firm Psychmedics, disputes the Utah results, saying that
other studies have failed to find a hair color bias. Only one comparison
matters to employers: who's doing drugs and who isn't. Employees
who have brought the hair bias issue to court have uniformly lost
their pleas, he says, on the grounds that a positive test --whether
weak or strong -- is still a positive test. Steven Magura, director
of treatment research at the National Developmental and Research
Institute in New York, says a hair bias isn't likely to be important
when comparing testing outcomes between racial or ethnic groups,
or even individuals. A multitude of factors, from body weight to
genetics, affect the way a person processes drugs.
On the other hand, he says, a person
with dense, black hair, which stores up drugs more readily than
fine, blonde hair, might test positive long after he had actually
used the illegal substance, whereas a blonde might test negative
sooner. |