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Christy Hammond
Christy Hammond, Bachelor of Science in Nursing
Category: Health
Satisfied Customers: 1529
Experience:  I have a B.S.N and more than 10 years of training and experience in patient care and education
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Can bactrim create a false pos drug test? tested pos for

Customer Question

can bactrim create a false pos drug test? tested pos for cocaine and have not touched it! also have had severve bacterial infec. low B levels and red blood cell count has been off.
Submitted: 8 years ago.
Category: Health
Expert:  Christy Hammond replied 8 years ago.

HiCustomer Thank you for asking your question on JustAnswer. There is no reported link between bactrim and false positive drug screens. Amoxicillin and Ampicillin are antibiotics that have been linked to false positive cross reactions for cocaine. Certain conditions including: kidney disease/infection, diabetes, and liver disease/infection can cause false positive results for cocaine. Your real concern is the positive results for benzodiazepine and cocaine. There are no drugs currently identified that can be linked to both cocaine and benzodiazepine false positives. If the test was repeated by the same lab or on the same specimen contamination or mishandling of the specimen is a possibility. If your infection is in the kidneys or affecting the kidneys this may explain the positive cocaine screen and there is a long list of drugs that can cause a false positive for benzodiazepine. For a complete and accurate list of drugs that can cause cross reactions click here. As unlikely as this may sound it is possible. Fot example: if you are on pain management the benzodiazepine may be a prescribed medication while the cocaine could be explained by kidney infection.

If the second test provided was a standard immunoassay, or a rapid test there is an increased chance of false results. Any positive results should be confirmed by a more accurate and specific test using gas chromatograph/mass spectrometer may be able to differentiate the cause for false positive. This is not 100% accurate-I believe diabetes can affect even the GC/MS but may be worth a try.

I hope this works out for you, eventually. Good luck and best wishes, Christy

Expert:  Family Physician replied 8 years ago.
It is important to understand the different technologies currently used for drug testing.

The technology used in screening tests (immunoassay) is very sensitive, relatively fast and inexpensive. This technology is the basis for the screening tests in most commercial drug tests and the "on-site" tests that many physician use in their office. The down side of this technology is the risk of false positives. For this reason, and test used for legal purposes such as employment testing can not rely on this technology as the only basis for legal action.

Gas chromatography/mass spectroscopy (GC/MS) is the industry "gold standard" used in the DOT and federal employment drug testing programs. This technology is more expensive and time consuming. It is used to confirm the positive results found on screening tests.

If your doctor did a on-site test without GC/MS confirmation, then there is a chance that one or more of the reported causes of false positives would account for your results. If the test was confirmed with GC/MS, then a false positive would NOT be possible. You should check with your doctor if this was confirmed with GC/MS. If not, I would ask that the test be confirmed by GC/MS.
Expert:  Christy Hammond replied 8 years ago.

I agree with the Doctor and I'm always glad to hear his input. The outcome in this situation will rely heavily on what test has been used so far and your options for re-testing. By definition any positive result using GC/MS is a true positive. Diabetes can result in a positive for alcohol due to fermentation of the sample, but for your purposes it should exonerate you of illicit drug use. If you are 100% positive you have had no exposure to cocaine and any use of benzodiazepine was limited to a prescribed anti-anxiety or sleep medication, then you may consider requesting the more sensitive test if it has not been done. If there is any chance that you were exposed to cocaine you will be taking a chance by requesting GC/MS, but if your confidence is high it may be worth a shot. I hope things work out for you in the end of this ordeal. Please let me know if I can answer any follow up questions that arise. Take care, Christy

Christy Hammond, Bachelor of Science in Nursing
Category: Health
Satisfied Customers: 1529
Experience: I have a B.S.N and more than 10 years of training and experience in patient care and education
Christy Hammond and other Health Specialists are ready to help you
Customer: replied 8 years ago.
asked for gc/ms test they said it was already done. Lost my job today. i am 100% sure that i have not done cocaine. But none of that seems to matter. I did go to hospital and it seems that i do have severe kidney infection. follow up with urologist this week. as far as diabetes? my father is diabetic. I dont know how much i will be able to follow up as my health ins. was through my work.
Customer: replied 8 years ago.
I would still like to thank you for your time and response
Expert:  Christy Hammond replied 8 years ago.

You're welcome, I'm sorry about your job. I believe you about the cocaine. If the benzo is in a medication you've taken, that plus the kidney infection may explain your results. The evidence that kidney infection causes a cocaine false positive is sketchy and GC/MS should have proven accurate. Diabetes would only cause a positive screen for alcohol as far as I know. People are rarely dosed with drugs containing cocaine but there is a drug marketed as ecstasy which combines a sedative and stimulent to make a cheap counterfeit pill they can sell at X prices. You didn't mention anything that would lead me in that direction but there has to be a explanation so it's at least worth mentioning.

You have the right to continueyour health coverage at group rates as long as your employer doesn't call this "gross misconduct". Click here to read about COBRA. The ADA act may cover your situation, click here for this info.

I hope this all works out for you. It is a harsh set of consequences no matter the details. Take care, Christy

Customer: replied 8 years ago.
I do drink on occasion. however, have not since i have been on meds. do not do any other drug except what is prescribed. cymbalta,1st bactim,then cipro,miripex,elavil,loritab,flexiril,naproxyn. i am really at a total loss.
Expert:  Christy Hammond replied 8 years ago.

A cross reaction would be caught by the GC/MS follow up, I thought maybe a drug that actually contain a benzo, but prescribed for a secondary reason (like Valium for muscle relaxation) I've hit a road block too. Short of someone spiking your drink I can find no new possibilities. If I find anything I will let you know. Good luck to you, Christy