False Positives on Drug Tests, page 159

False Positives Forum

This forum is intended to help those who Do NOT Abuse Drugs. We do NOT support the illegal use of any substance. If you have experience with false positives, share your experience. What would you tell someone about drug testing and false positives? Please remember that we do not give medical or legal advice.

Synthetic marijuana
Date: 11/17/2011
How long does synthetic marijuana stay in your system. Can you test positive two months after taking it? Your prompt response will be greatly appreciated.


AskDocWeb: Over the last decade a number of different synthetic versions of marijuana have shown up on the market. Unfortunately the performance characteristics of the synthetic versions are not well established. There are no scientific studies on humans about how long these synthetics actually stay in your system.

I tested positive for THC
Date: 11/19/2011
I tested positive for thc havent touched it in 3 years, I do take hycodan, hydrocodone, ibuprofen 600, Zyrtec d, lortadine, soma, cloanzepam, and allbuteral inhaler could these be the cause.


AskDocWeb: The only one that might explain your test result is Ibuprofen, which several sources say that it sometimes shows up as a false positive for Marijuana (THC).

Tested positive for cocaine
Date: 11/21/2011
I tested positive for cocaine on a drug screen and I’ve been taking biaxin and amoxicillin. Would either of these cause a false positive?


AskDocWeb: The Biaxin wouldn’t but several sources say that amoxicillin could show up as cocaine on urine drug tests. Fortunately the confirmation test eliminates that kind of false positive.

Positive for methadone
Date: 11/21/2011
My son is in a rehab. Takes Ultram and Celexa daily for knee pain and depression. Drug screen (urine dip) positive for methadone. Denies any use. 6 weeks ago same happened but urine sent off to reference lad was neg. rehab refuses to believe him a second time. Will either of these drugs cause a false positive? Please send answer to my email. Thank you.


AskDocWeb: Sorry Renee, neither of those have been documented to cause a false positive for methadone on urine drug tests. Currently, the possibilities make up a short list; antihistamines in general, Bentyl®, Elavil, Methadose, Nyquil, Phenergan®, Physetone, and Vicks Formula 44M.

My doctor kicked me out
Date: 11/22/2011
I have been a pain patient for over 10 years now and recently failed a UA. I am prescribed oxycodone, methadone, Valium, trileptal, and adderall. I also take benadryl, advil, and excedrine. I had a dirty drug screen for barbituates. I have no idea what that is. Is there anything I took or a combination of my meds n how my body metabolises these meds that could cause this? Please help. My doctor kicked me out and now I don’t know what to do and this also makes me look bad when I follow all the rules. I am a pain patient not a drug seeker and they are making me look like one.


AskDocWeb: Hello Robb. Sorry to hear that they kicked you out. None of your meds have been reported to show up as barbiturates. However, that is not proof of anything. Everyone that has to take a drug test should know what a confirmation test is and when it is appropriate to request one. Often there is a limited amount of time to respond to a false positive. Unfortunately there is little you can do about it once you are out the door.

False positive in urine drug screens
Date: 11/23/2011
I was wondering if the antiemetic odansetron, Lodine or chamomile tea can cause a false positive in urine drug screens? Any info is appreciated.


AskDocWeb: Several sources say that Lodine may show up as a false positive for marijuana (THC). The others have not been reported to cause any problems on urine drug screens.

Fluticasone nasal spray
Date: 11/23/2011
Hi there I was perscribed Fluticasone nasal spray during my pregnancy and I tested positive for amphtimines so now I’m dealing with child protective services I am curios if this perscription could cause a false negative!


AskDocWeb: Fluticasone nasal spray has not been documented to cause false positives. However, if you are dealing the child protective services then you would likely benefit from getting a confirmation test (GC/MS). That is, if you haven’t used amphetamines.

Is this even possible?
Date: 11/24/2011
I was prescibed azithromycin which I have a perscript for, on a Saturday and a oxycodeine on Sunday for my back, because I had been having problem with it recently after doing manual labor, and I had an accident with a semi 2 years ago. I also take a isa-test, which is a test booster and extrogen blocker, and HGC, which is a human growth complex. I live a pretty healthy lifestyle, work hard, eat right, I only took the oxycodeine one time. two Monday after 9(days) I get randomed for DOT at work and it comes up positive for morphine, codeine, and heroin. Is that even possible? I am requesting a test of the second sample. Is it possible the antibiotics are causing a false positive? What do you think is going on? and will this second test be a more accurate test? Thank you.


AskDocWeb: Unless the test you took is 100% accurate it has an error rate, which makes a false positive possible. While azithromycin has not been specifically mentioned, some antibiotics have shown up as a false positive for heroin. If the second test is a confirmation test rather than just a retest then it should eliminate any false positives.

Date: 11/24/2011
Can mucinex cause non negative on swab pre employment drug test? Or alcohol?


AskDocWeb: Mucinex has more than one formula. Mucinex Children’s Cough contains dextromethorphan and guaifenesin. Dextromethorphan is a cough suppressant that affects signals in the brain that trigger the cough reflex. It has also shown up as false positive for morphine, heroin, and opiates on urine drug screens.

Mucinex D contains a combination of pseudoephedrine and guaifenesin.. Pseudoephedrine is a decongestant that shrinks blood vessels in the nasal passages. Unfortunately it also may show up as a false positive for amphetamines (speed). Both formulas are alcohol free.

Cocoa butter lotion
Date: 11/25/2011
I have never used cocaine in my life. I am an RN and went for a new employee health appointment a couple of days ago. I DID shave that morning, I DID use cocoa butter lotion ALL over my body including my perineal/bikini region. I DID test positive/inconclusive for my UDS. It IS POSSIBLE. It DID happen to me.


Date: 11/25/2011
I’m a 30 year old male that currently taking doxycycline for acne. I work for a hospital and I’m do for a urine drug test this Monday. Should I be worry? If yes, what should I do or tell my employer?


AskDocWeb: Doxycycline has not been reported to cause any problems on urine drug screens so you will likely be okay. Unfortunately false positives can occur for a number of reasons so be prepared to request a confirmation test if you believe your test result is incorrect.

False positive for meth
Date: 11/25/2011
I had a false positive for meth, with the confirmation test it came back as 1200 ng/ml of methamphetamines, but no amphetamines were present. What does that mean? Also was positive for alcohol at 0.020 and confirmation test was 0.024 & I didnt use meth or alcohol???? Can you help explain this or tell me where to find answers?


AskDocWeb: As we understand it, in order for the result to be a valid positive test result for methamphetamine the sample must also contain d-amphetamine. In checking the “Mandatory Guidelines for Federal Workplace Drug Testing Programs, published by the Substance Abuse and Mental Health Services Administration (SAMHSA)” we find this quote:
“in order to report a specimen positive for only methamphetamine, the specimen must also contain the metabolite amphetamine at a concentration equal to or greater than 200 ng/mL by the confirmatory test. This proposed requirement would ensure that high concentrations of sympathomimetic amines available in over-the-counter and prescription medications will not be misidentified as methamphetamine.” (The bold emphasis is ours)

For a possible explanation of the positive for alcohol, see answer for Pam October 30th.

Positive for benzodiazepines
Date: 11/26/2011
I’ve tested positive for benzodiazepines up to eight or nine weeks after I’ve ceased using them. I’ve always been told I shouldn’t test positive after eight or nine days? What’s up?


AskDocWeb: The 8 or 9 days is an average for the length of time that benzodiazepines can be detected. In general, it takes about 5 half-lives for a body to clear a drug from the system. However, not all benzodiazepines are created equal. Some have an elimination half-life as short as 2 hours (Triazolam), which would mean that it is out of your body in as little as 10 hours. On the other hand, some benzodiazepines have an elimination half-life of up to 200 hours (Chlordiazepoxide, Medazepam, Prazepam), which would mean that it may show up for as long as 42 days. (200 * 5 / 24 hours = 41.7 days)

It is also important to note that the elimination half-life of long half-life benzodiazepines is twice as long in the elderly compared to younger individuals. Individuals with an impaired liver also metabolize benzodiazepines more slowly.

Date: 11/26/2011
Can you please tell me if it is possible for someone taking Suboxone (buprenorphine) to give up false positives in urine tests? Recently tox results from five different people gave positive results for four different substances including fentynal and hydrocodone. Please comment on what false positives can be given by suboxone. Thank you.


AskDocWeb: Suboxone may test false positive for oxycodone but we haven’t heard of it testing false positive for anything else.

Positive for Suboxone
Date: 11/26/2011
I tested positive for Suboxone on an oral drug test. Let me say that I am 100% positive that I HAVE NEVER taken Suboxone in my entire life. The doctor I went to drug tested all new patients just because the area had high rate of drug use. He then discharged me and would not see me anymore. It has been about a month and I am still crying! I have gone as far as calling the drug company who makes the medication and all they said is that it has been reported that Ultram has caused false positives. I have that listed as an allergy. There’s no way I would take that. Let me guess….contact a toxicologist. Please help. I don’t have anything to hide. But now thanks to all of this, I now have a TRUE PHOBIA of drug tests. All I have done is smoked pot in high school. I am now in my late 30’s. This could hurt my job and I’ve never abused drugs.


AskDocWeb: What medication were you taking at the time of the test? Was the test result confirmed by additional testing (GC/MS or LC/MS/MS)? A confirmation test is often required when testing for the workplace. Have you inquired about the chance of getting retested or taking a blood test?

Date: 11/26/2011
with Methotrexate give a positive reading for meth and a ua? drug test?


AskDocWeb: We have read about false positives for pregnancy tests by those using Methotrexate but not for meth.

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