Feedback on False Positives from Drug Testing, page 23

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.

Subj: How long drugs stay in the body
Date: 10/17/2007
I am a social worker and my colleagues and I would like to know if we can obtain any information or article on how long drugs stay in the body system, especially illegal drugs.


AskDocWeb: There doesn’t seem to be a good source for that kind of information. Here’s what we have been able to put together.

The amount of time that any drug stays in the body depends on several factors. It varies between men and women, and depends on factors like body weight, hydration, metabolism and the amount of drug that was used.

Cocaine is usually eliminated within (CENCORED) days.

The active metabolite of marijuana is stored in the fat cells of the body. The more smoked and the heavier the body, the more metabolite in the system. Typically the THC stays for about (CENCORED) days.

Alcohol (one standard drink) stays in the body for 1 to 2 hours. If more than one drink in an hour, it will take longer for the alcohol to be metabolized and leave the body. This also depends on the amount of food eaten before alcohol consumption commences.

Marijuana takes (CENCORED) days to leave the body of occasional users. For frequent users, it stays in the body for (CENCORED) weeks.

Cocaine stays in the body for (CENCORED) days.

Opiates (like heroin) stay in the body for (CENCORED) days.

Amphetamines (speed or uppers) take (CENCORED) days to leave the body.

Benzodiazepines (like ValiumĀ® or AtivanĀ®) stay in the body for (CENCORED) days for occasional users. For frequent users, it takes (CENCORED) weeks to leave the body.

Subj: List of False Positives
Date: 10/17/2007
I would like find out how you came up with your list of “False Positives” for drug testing. I am a Parole Officer and worry about false positives. I certainly do not want anyone to suffer consequences for inaccurate drug test results. Please advise.


AskDocWeb: The list comes from a variety of sources, from the websites of those companies that sell the drug tests, drug testing laboratories, drug companies, research reports, counseling centers, and magazine articles. Next year we will be adding reference notes to the list but it is a big list so be patient.

Subj: Comprehensive list of foods that cause a false positive
Date: 10/18/2007
A friend tested positive on a urinalysis, but did not drink alcoholic beverage. He thinks it might be the scope he used to rinse his mouth. He would really benefit from a comprehensive list of foods that cause a false positive on a Urinalysis test. Do you have such a list? If not, do you know where he might get one? He’s in a transitional living program that will kick him out of his apartment if he’s found positive again. HELP!


AskDocWeb: We have not found such a list, that’s why we created this list.

Subj: Zantac
Date: 10/23/2007
I am taken Zantac for heart burn. I also am on Methadone. For some reason I looked and on the list at the clinic it says that zantac will cause false positive. I would like to know why and what does it should up as. One more question like one I read on your page. I have been clean for one year and seven months. There is no way I could have tested positive for cocaine. I did. I have no explanation for this is there anything that could change my results. By the way the test I failed was about two months ago. Now the Zantac question just came up today. Thanks for your time.


AskDocWeb: We don’t have all the answers but Zantec has been reported to cause a false positive for Amphetamines.

Subj: Will these show positive?
Date: 10/23/2007
I starting a new job and have to take a drug screening. I am currently taking, Klonopin 1mg, Zoloft 50mg, Melatonin 3mg, and Chamomile tea. Also Caffeine free Hydroxycut. These are all an attempt to lower my heart rate, caused by anxiety attacks. Will these show positive?


AskDocWeb: It doesn’t happen all the time but Zoloft has been reported to cause false positives for benzodiazepines.

Subj: Lexapro
Date: 10/24/2007
I have recently tested positive for a lexapro level. I have never taken this medication before. Is there anything that would cause this false positive?


AskDocWeb: Nothing has been reported.

Subj: Positive for oxycodone
Date: 10/24/2007
I recently took a random hair follicle drug test for my job and it came back positive for oxycodone. I have a prescription for hydrocodone and have been using it for a few years to relieve pain due to a shoulder dislocation that dislocates at random. I was told by my pharmacist that the two drugs are in the same family and I should be fine as long as I present my prescription for the hydrocodone. My employer is not honoring my proof. They said that both drugs were two totally different medications and if I cant produce a prescription for the oxycodone, I will be terminated. Please tell me what to do seeing that I don’t use oxycodone.


AskDocWeb: If you are innocent, always get a confirmation test to prove it, either a gas chromatography, mass spectrometry (GC/MS), or high-performance liquid chromatography. In addition, you might be able to get your doctor or the pharmacist to call (or write a letter to) the employer on your behalf.

Subj: False positive for THC?
Date: 10/25/2007
Can ambien, trazadone, clanipin, zoloft, vitamin b12, lamictal tylenol, musanex cause a false positive for THC?


AskDocWeb: Please check the list.

Subj: Lidocaine, Marcaine
Date: 10/25/2007
1%Lidocaine, Marcaine. These when used in conjunction with injectable steroids (cortisones) will give false positives.


Subj: Tested positive for cocaine
Date: 10/25/2007
I have hep c. Lately I tested positive for cocaine twice and I have no exposure to cocaine. Can a bad liver cause these test results. I also took some percodan and tested positive for opiates two weeks later…can opiates stay in my system that long?? Is it because of a poor filtering liver with hep C? Thanks,


AskDocWeb: Both the drug percodan and liver problems have been reported to cause false positives. Some drugs (not all) are processed by the liver. Any reduction in the liver’s ability to function will extend the detection time for those drugs.

Subj: Diet pills
Date: 10/27/2007
Recently my ex-husband tested positive for amphetamines and methanphetamines. The test result showed his meth positive level for 594pg/mg. The cut off was 100pg/mg. He says he has been taking prescription diet pills. Can diet pills cause a meth positive?


AskDocWeb: There are many diet pills out there, and it depends on what the ingredients are in them. Read the label and check this list.

Subj: False positive for Methamphetamines?
Date: 10/31/2007
What can cause a false positive for Methamphetamines. I took a court ordered drug test and failed testing positive for methamphetamine and amphetamines. I did not do any drugs. I went and got a hair sample to clear my name, but I had taken 4 OTC Sinus pills (I think Tylenol, maybe a generic). I tested positive for methamphetamines on the hair sample, but it was negative for amphetamines this time. What does this mean? Can the hair sample help my case?


AskDocWeb: The over the counter sinus tabs could be the culprit. Always request a GC/MS confirmation test.

Subj: UA test came up positive
Date: 10/31/2007
I was diagnosed with a rare kidney disease (i-g-a Nephropathy) over a year ago and have been taking NORVASC, AMITRIPTYLIN, LISINOPRIL, OXYCODONE (for headaches) and of course OMACOR to regulate the degeneration of the kidneys. I was involved in an accident on a job site and was required to take a UA test. I came up positive but I don’t indulge. When I talked to the agency handling the outcome their first comment was “do you have cancer?” I informed them I didn’t but that I had a mean kidney disease. They were un-interested. When I returned from the field to my company’s headquarters my Regional Manager asked if I had been around it or to a concert. I stated honestly “NO”! I was terminated. I am now trying to get my UA results for my lawyer. Can you shed any light on this endeavor?


AskDocWeb: If the company relied solely on the UA test without a GC/MS confirmation then you might have a case, but then we are not lawyers. Good luck.

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