Medication causes false positive for THC

More than 11,000 Coloradoans, 6,139 of which live in Denver, were reported to be living with HIV/AIDS in 2010 according to aidsunited.org, and in the past that number has risen by three percent each year. Some of these people may be affected by false positive results for THC found in marijuana on urinalysis drug tests used by police officials and in the work place.

Atripla is the number one prescribed treatment regimen for HIV according to atripla.com. This drug contains three different drugs, one being Efavirenz, also known as Sustiva, which is reported to cause false positives for THC in certain UA tests.

This issue is recognized within the medical and drug manufacturing communities, but is potentially overlooked by those outside of these communities. Summit County resident Mitch Ringquist, who takes Atripla daily, was personally affected by this situation.

In September 2011, Ringquist was arrested for a DUI and was sentenced to 180 days of jail time. As a part of his initial guilty plea for the DUI, the Fifth District Court granted Ringquist work release for the duration of his sentence. The parameters of the work release program include an initial pre-screen drug test and ban of the use of alcoholic beverages or nonprescription drugs. Any prescribed medication was to be labeled specifying the medication and the prescribing physician.

“The initial test is conducted when an inmate is booked into the jail; in Mr. Ringquist’s case, the initial test came back clean,” said Tracy LeClair, the administrative assistant/public information officer for the Summit County Sheriff’s Office.

As a result of his clean test, Ringquist began the work release program, and his life settled into a steady routine. “I would check out of jail at 9 a.m., and I would check back in to jail at 9 p.m.,” he said. “During my 12-hour day, I would call the jail every time I moved my person. The deputies eventually told me to stop calling.”

Not only did Ringquist have to check in via telephone, he also needed signed verification for his various locations throughout the day. “Every time I would do therapy, I would have my therapist sign my paper. Every time I went to a meeting like Alcoholics Anonymous, or Narcotics Anonymous, I would have people sign off and no longer remain anonymous,” he said.

Ringquist works as an in-home patient care professional, and his primary functions in this position include grocery shopping, preparing meals, and assisting his client with everyday tasks.

“My client has limited mobility, but still has the ability to move around and get to a comfortable position or warm up a meal I had prepared the previous day,” he said.

During the two days per week that Ringquist was restricted from working, his client was left to his own devices to maintain a comfortable lifestyle.

On the morning of May 21, Ringquist had a UA conducted through a federal testing agency, Bair Counseling, for a previous parole-related incident. This test came back negative for THC and cocaine.

“Now, that test, they sent to an actual lab that takes into account my medication,” Ringquist said.

That same night when Ringquist checked in at the Summit County jail, he was given a random drug test by the county. “Those tests are done in-house, with the results returned in 2–5 minutes,” LeClair said.

Ringquist’s test came back positive for THC and he was removed from the work release program. “Mr. Ringquist insisted the results were incorrect,” LeClair said. “So our Detentions Commander contacted Mr. Ringquist’s physician, who stated that none of Ringquist’s prescription medications should result in a positive reading for THC.”

However, Sustiva, found in Atripla, has been found to cause false positives for THC in certain UA tests. “Sustiva and its ability to cause a cross reactive test for cannabinoids, marijuana, is well known, and the information is actually contained in the package insert in the drug,” said Dr. Steve Johnson, who works in the Infectious Diseases department at the University of Colorado Hospital and has written a paper on Human Immunodeficiency Virus (HIV) Vaccine Therapy. “A package insert for a medication isn’t just from a pharmaceutical company; it’s actually FDA approved.”

The package insert for Sustiva states that “False-positive urine cannabinoid test results have been observed in non-HIV-infected volunteers receiving SUSTIVA when the Microgenics CEDIA DAU Multi-Level THC assay was used for screening. Negative results were obtained when more specific confirmatory testing was performed with gas chromatography/mass spectrometry.” Three other assays, or tests, were analyzed and did not produce false positive results.

PubMed.gov also published a study in November in which they found the Rapid Response () test strips yielded false positive results in 28 out of 30 samples while three other tests did not.

According to the Summit County Sheriff’s Office, once detained in prison, Ringquist had to wait two weeks to submit another sample. “This second test also came up positive,” LeClair said. “The Commander then made the decision to send that sample to the lab. This was an exception to our normal procedures, as work release is a privilege and not a right.”

The results of the lab were incongruent with the results of the in-house test. “The test came back negative for cocaine and THC. Ringquist was put back on work release and the jail staff was ordered to ignore any future THC positives,” LeClair said.

With the ultimate results of Rinquist’s various UA tests coming back negative, he was alleviated of certain work release fees and received a 60-day sentence reduction.

Ringquist isn’t alone in dealing with this issue. “In my own setting, I think it’s come up three, four times something like that,” Dr. Johnson said. “So I imagine, across providers, this comes up with some frequency and so it is an issue for patients on this drug who are working, for example, and have to provide a test sample.”