Mayo Clin Proc. https://www.cdc.gov/nchs/fastats/drug-use-illicit.htm, https://www.samhsa.gov/workplace/resources, https://www.samhsa.gov/sites/default/files/workplace/2010GuidelinesAnalytesCutoffs.pdf, https://www.federalregister.gov/documents/2017/01/23/2017-00979/mandatory-guidelines-for-federal-workplace-drug-testing-programs, https://accesspharmacy.mhmedical.com/content.aspx?sectionid=210267566&bookid=2569#216818178, Amantadine, aripiprazole, atomoxetine, brompheniramine, bupropion, chlorpromazine, desipramine, DMAA, ephedrine, fluoxetine, labetalol, metformin, ofloxacin, phentermine, phenylephrine, phenylpropanolamine, promethazine, pseudoephedrine, ranitidine, selegiline, thioridazine, trazodone, nonprescription nasal antihistamine/decongestant inhalation, Baby wash products, dronabinol, efavirenz, ibuprofen, lamotrigine (on screenings for synthetic cannabinoids), naproxen, niflumic acid, proton pump inhibitors, Ambroxol, amitriptyline, benzphetamine, bupropion, buspirone, cephradine, chlorpromazine, desipramine, diltiazem, doxepin, fentanyl, fluoxetine, haloperidol, imipramine, labetalol, metoclopramide, prochlorperazine, risperidone, sertraline, thioridazine, trazadone, verapamil, ergonovine, lysergol, brompheniramine, imipramine, methylphenidate, fentanyl, sertraline, Diphenhydramine, doxylamine, chlorpromazine, clomipramine, doxylamine, quetiapine, thioridazine, verapamil, Amisulpride and sulpride, codeine, dextromethorphan, diphenhydramine, dihydrocodeine, morphine, methadone, morphine-3-glucuronide, creatinine, dihydrocodeine, levofloxacine, ofloxacine, morphine, naloxone, ofloxacin, petanzocine, psychotropic drugs, quetiapine, rifampicin, tapentadol, tramadol, verapamil, quinolones, quinine, Dextromethorphan, diphenhydramine, doxylamine, ibuprofen, imipramine, ketamine, lamotrigine, MDPV, meperidine, thioridazine, tramadol, venlafaxine. Results are relatively rapid, and the test can screen for a wide variety of drug metabolites. While urine drug tests are most commonly used, their accuracy depends on a number of factors, including the frequency of drug use and the how fast the drug is metabolized by the body. If abuse is suspected, urine drug tests are available to help clinicians detect its presence and intervene in order to optimize patient outcomes. As medical and recreational use expands across the country, heres what your patients need to know about potential interactions, Its best to steer clear of these things while taking this blood pressure medication, Research conducted at Boston Medical Center shows that drug tests produce false positives in 5% to 10% of cases. The DHHS cutoff values were developed for adults, and lower thresholds should be used for infants. They both use similar principles. When methamphetamine is detected or both amphetamine and methamphetamine are detected, then the lab can run a d,l-isomer test to try and narrow the source of the positive methamphetamine finding (Figure 1). Does Zantac (ranitidine) cause false positives for methamphetamine? This article is not medical advice. Pract Pain Manag. Summary. The weight loss drug phentermine, may produce a false positive drug test. Esposito FM, Crumpton S, Mitchell J, Flegel RR. [PMID 23088194] Follow me on Twitter . 2011 Jun;7(2):105-8. doi: 10.1007/s13181-010-0131-5. eCollection 2022. People taking the HIV medication Sustiva (efavirenz) may obtain false positive drug test results. A false positive can potentially lead to a loss of employment, jail time, loss of privileges under probation, revocation of medical license, and exclusion from competitive sports. As well, false positive urine tests for cannabinoids have been reported among those taking Sustiva. Several common prescriptions, over-the-counter medications, herbs, vitamins, and even some foods could trigger a false positive drug test. Bookshelf 2022 Feb 17;2022:7542311. doi: 10.1155/2022/7542311. If the IA test is negative, no further testing is required and the amphetamines are considered negative. 2016 Mar;40(2):97-107. doi: 10.1093/jat/bkv133. I would appreciate it if you please leave a five star rating at the top left part of your screen, since this is the only way I have tank credit for this answer. Cold remedies, hay fever remedies, nasal decongestants, diet pills, fluoxetine (Prozac), methylphenidate (Ritalin), bupropion (Wellbutrin), beta blockers (blood-pressure remedies) Barbiturates. 10 Kinetics Interaction of Microparticles in Solution (KIMS, Roche), a monoclonal antibody assay, identified possible false-positive results for chlorpromazine, clomipramine, and thioridazine. Many of the over-the-counter drugs that are used to treat ADD and ADHD have components that are similar to those found in methamphetamine 3.Ritalin, Adderall and Dexedrine may all cause someone to have a false-positive drug test for meth 1. Answer (1 of 5): Adderall will pop for amphetamine but not methamphetamine. . August 18,2016. Unable to load your collection due to an error, Unable to load your delegates due to an error. 2012;12(10). , so if you are taking the drug, it is possible that you will test positive for steroids. If it is prescribed, make sure you have the label from the pharmacy, which will show that the medication was prescribed to you. These tests do not use antibodies and can accurately determine the exact molecule being looked for. Amphetamine positive urine toxicology screen secondary to atomoxetine. Labetalol can also cause a false positive for amphetamine or methamphetamine because a labetalol metabolite is structurally similar to amphetamine. Furthermore, if they can prove they are taking a medicine that can produce a false positive (by producing a legitimate prescription), the administrator may schedule another test 30 to 60 days later. Based on how urine drug tests work, it makes sense that anticonvulsant drugs have a . Drug concentration level thresholds are used in reporting of positive and negative reports for urine drug testing.2 If a test detects a concentration above the threshold, it is reported as positive, and vice versa for negative results. Learn how we can help. Common medications like Trandate (labetalol), a beta blocker used to treat hypertension, and Cardizem (diltiazem), a calcium channel blocker used to treat hypertension and chest pain, may result in false positive drug test results for LSD. Research conducted at Boston Medical Center shows that drug tests produce false positives in 5% to 10% of cases. Urine tests can detect more recent drug use, while hair follicle . Rockville, MD: Substance Abuse and Mental Health Services Administration, 2011. http://www.samhsa.gov/data/2k11/dawn/2k9dawned/html/dawn2k9ed.htm. An otherwise healthy 27-year-old female with a history of attention deficit hyperactivity disorder (ADHD) treated with atomoxetine had an acute onset tonic-clonic seizure. After a California mom's post about testing positive for meth due to an inhaler went viral, the questions of whether an inhaler could cause a false positive on . Schwebach a, Ball J. Urine Drug Screening: Minimizing False-Positives and False-Negatives to Optimize Patient Care. If only amphetamine is detected, once again no further testing is needed. These meds include pseudoephedrine, labetalol, bupropion, trazodone, and chlorpromazine. Adderall. The drug has been linked to false-positive drug test results for amphetamine. False-positive results A drug metabolite is a remnant of the drug after being broken down by the body, and the most common metabolizer of a medication is the liver. A false positive means that the test has detected the presence of these substances in your body when you havent actually taken them. Accessed October 4, 2012. This test is more specific than immunoassay testing, as it detects drugs by molecular structure. Research suggests that 10% to 15% of drug tests yield false negative results. Introduction While any discovery of metabolites in hair tests is believed to be undeniable proof of marijuana use, a new study from the Institute of Forensic Medicine in Freiburg, Germany finds that it's possible to get a false positive. Additionally, many enzyme immunoassays are designed to detect nordiazepam or oxazepam, metabolites of diazepam, chlordiazepoxide, and clorazepate.11 Therefore, lorazepam and clonazepam are not reliably detected by immunoassay, and GC-MS should be utilized if detection of these agents is desired. An understanding of these limitations is necessary to identify false-positive and false-negative results. If it is an OTC product, have some kind of documentation (the container it was in, a note from your physician, etc.) Clinical Interpretation of Urine Drug Tests: What Clinicians Need to Know About Urine Drug Screens. Results from such tests should be confirmed using additional analytical methods, including gas chromatography-mass spectrometry. Desipramine and amantadine causing false-positive urine test for amphetamine. Urine drug screens are the most common test (although other body fluids may be analyzed). It is also a good idea to avoid taking any vitamins or similar supplements until you take the test. Each drug varies in the amount of time it can be detected in the urine (Table 2).2 The detection time is primarily based on half-life and the presence of drug metabolites. Methamphetamine is illegal except when it is prescribed by a physician for a very limited number of medical conditions. All of the following medications have documented cases of causing a false positive for either amphetamine or methamphetamine: Amantadine. DMAA (1,3-dimethylamylamine), found in some dietary and weight-loss supplements. Many drug abusers will make the commitment to stop, and you therefore need an accurate test to verify and confirm this. D-methamphetamine increases alertness, concentration, energy, and in high doses, can induce euphoria, enhance self-esteem, and increase libido. These traits make d-methamphetamine very attractive to a potential abuser. The effect lasts longer than with cocaine, it is cheaper, and it is easy to make with commonly available ingredients. New York, NY: Pharmacia & Upjohn Company, a Division. Grunbaum AM, Rainey PM. It is intended for general informational purposes and is not meant to be a substitute for professional medical advice, diagnosis, or treatment. InOut Labs is a nationwide provider of employee drug testing services, and your best choice for affordable, direct-to-consumer health tests. 2017 May;92(5):774-796. doi: 10.1016/j.mayocp.2016.12.007. Surgery 45 years experience. Determining the source of the methamphetamine is an important next step and is not always as straightforward as it appears. As noted, the first test is the IA screening test. may obtain false positive drug test results. Alcohol does not affect the accuracy of pregnancy tests. False positive for Methamphetamines is quite common because some amphetamine (AMP) and Methamphetamine urine immunoassay (IA) kits are prone to false-positive results due to poor specificity of the antibody according to a study published in the Journal of Analytical toxicology. The Adderall will show up as a false positive for Methamphetamines. Methylphenidate: Used to treat ADHD, methylphenidate (Ritalin) is a well-known cause of false positive tests for amphetamine or methamphetamine, and LSD. Please feel free to reach out to him directly if you have any inquiries or want to connect! MeSH They work by utilizing antibodies to react to specific drug compounds. Know if the meds you are taking might cause a false positive and notify the administrator of the test. official website and that any information you provide is encrypted There are many different over the counter and prescription medications that have been reported to cause false positives for methamphetamine on a drug test. Hair strand drug tests detect the presence of drug metabolites in the follicle. When consumed in large quantities (such as in a poppy seed bagel or muffin), the tiny black seeds might cause a false positive drug result for opioids. , including the frequency of drug use and the how fast the drug is metabolized by the body. A false-positive test result means that your drug test shows the presence of a medication or substance that you aren't actually taking. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. Frequency of false positive amphetamine screens due to bupropion using the Syva EMIT II immunoassay. The .gov means its official. When a patients urine drug screen tests positive for methamphetamine by mass spectrometry, the result has serious implications for the patient and the provider. Pseudoephedrine, the decongestant found in original Sudafed (the kind you have to sign for) can/will cause a false positive under one of those two test columns. UIC's seven health sciences colleges and health care delivery enterprise. Accessed October 9, 2012. Reports of false-positive results were found for the following formulary and nonprescription medications: brompheniramine, bupropion, chlorpromazine, clomipramine, dextromethorphan, diphenhydramine, doxylamine, ibuprofen, naproxen, promethazine, quetiapine, quinolones (ofloxacin and gatifloxacin), ranitidine, sertraline, thioridazine, trazodone, venlafaxine, verapamil, and a nonprescription nasal inhaler. Psychiatrist.com https://www.psychiatrist.com/pcc/addiction/substance-use-disorders/i-have-never-used-methamphetamine-but-my-urinalysis-says-i-do/#:~:text=1%2D4%20Common%20medications%20that,bupropion%2C%20trazodone%2C%20and%20chlorpromazine. I've also heard that Claritin (the allergy medication) can,. J Am Coll Emerg Physicians Open. Can Certain Foods, Drinks, And Meds Cause A . trigger a false positive urine result for opiates. Bethesda, MD 20894, Web Policies Disclaimer. Moeller KE, Kissack JC, Atayee RS, Lee KC. A retrospective chart review of 10,011 urine drug screens found that of 362 initial positive amphetamine tests, 128 (35%) were false positives. Thats because the chemical structure of phentermine is similar to that of an amphetamine, so if youre taking the drug, it is likely to appear as a positive result on a 5-panel urinalysis. Prescription use of propoxyphene may cause a positive test result because the cut-off concentration for propoxyphene in urine (300 ng/mL) can be reached after medical use of this drug. This has prompted restrictions on the distribution of these over-the-counter (OTC) medications. RELATED: Benadryl details | Doxylamine details. Riboflavin, also known as B2, is found in hemp seed oil and may return a false THC (marijuana) reading. Dr. Brian Staiger is a licensed pharmacist in New York State and the founder of the Q+A website PharmacistAnswers.com. The clinician needs this critical information because without the d:l-isomer ratio, the clinician is unable to narrow down the potential sources of the methamphetamine. I would counsel [anyone who received a false-positive test to ask] the administrator to do a more specific test, says Dr. McFadden, who recommends samples be sent away to labs to have a more specific mass spectroscopy assay done. The d,l-isomer test also is performed by MS. Understanding each of the 3 testing steps is essential to clinical decision making related to patient care. So, if you are like most people who dont take the time to study the fine print, here is a list of prescriptions and over-the-counter medications that could cause a false positive drug test. Taking Sudafed can result in a false positive for amphetamine or methamphetamine. Some other medications that can cause a false-positive result can be ADHD meds such as Ritalin (methylphenidate), Quinolone antibiotics like Levofloxacin or Ofloxacin, or Metformin . Limit your exposure to toxins and do not spend time in toxic environments. He's answered thousands of medication and pharmacy-related questions and he's ready to answer yours! Pseudoephedrine: Used for sinus and nasal congestion, pseudoephedrine (Sudafed) can be the cause of false positive tests for amphetamine or methamphetamine. DeGeorge, Jr. M, Weber J. Methamphetamine Urine Toxicology: An In-depth Review. The https:// ensures that you are connecting to the For this reason, immunoassay testing should only be considered preliminary and should be followed up by confirmatory testing whenever a test comes back positive. Epub 2014 Jul 1. Opiate immunoassays detect morphine and codeine, the major metabolites of heroin and a common contaminant acetylcodeine, respectively.11 Therefore, they do not reliably detect semisynthetic and synthetic opioids. Certain antidepressant drugs are more prone to false-positive readings. While urine drug tests are most commonly used, their accuracy depends on a number of. Antihistamines and some sleep aids containing diphenhydramine (like Benadryl) could cause a false positive result for PCP or methadone. Promethazine. Heres what the experts recommend. A recent study by Esposito et al published in the Journal of Analytical Toxicology showed that d-methamphetamine percentages often were a few percentage points above or below the expected value based on the standard solutions they were testing. This was due to impurities in some of the derivatizing agents used. https://www.practicalpainmanagement.com/treatments/pharmacological/non-opioids/methamphetamine-urine-toxicology-depth-review, Did A Vicks Inhaler Cause My Positive Test? In addition to prescription medications, these other common substances can lead to a false positive drug test. The challenge for the laboratory is to differentiate between the d and the l isomer forms of methamphetamine. During World War 2, methamphetamine similar in structure to amphetamine was usedto keep military personnel alert and to improve endurance and mood. Thats because the chemical structure of phentermine is similar to that of an amphetamine, so if youre taking the drug, it is likely to appear as a positive result on a 5-panel urinalysis. ) There are many different over the counter and prescription medications that have been reported to cause false positives for methamphetamine on a drug test. Ibuprofen is still frequently reported in resources as a possible cause for false-positive cannabinoid immunoassays. 5-7 Non-amphetamine prescription, illicit, or over-the-counter . And certain drugs, such as tranquilizers, anticonvulsants, or hypnotics, may also cause false-positive results. Common Vitamins Supplements can cause a false positive test. In addition, benzphetamine (Didrex) is a schedule III medication approved for treatment of obesity. Pseudoephedrine is a decongestant that is commonly used to treat nasal congestion and sinus infections. What Can Cause A False Positive For Methamphetamines? Would you like email updates of new search results? hCG is produced by the placenta and is present in urine from . Annals of emergency medicine, 22(12), 19271928. Cutoff values were developed to mitigate false-positive results, especially in the workplace. Drugs.com provides accurate and independent information on more than 24,000 prescription drugs, over-the-counter medicines and natural products. The potential for false-positive UDS results was identified for the following medication classes on the clinic formulary: antihistamines, antidepressants, antibiotics, analgesics, antipsychotics . Pseudoephedrine: Used for sinus and nasal congestion, pseudoephedrine (Sudafed) can be the cause of false positive tests for amphetamine or methamphetamine. Drug testing can be performed using various biologic specimens, including urine, saliva, hair, sweat, nails, meconium, and blood. The main issue is the tests themselves. Prescription methamphetamine (Desoxyn) is composed entirely of the d isomer. Usually, an immunoassay screening test for methamphetamine is a methamphetamine/amphetamine combined test, so will detect any medication or substance that resembles methamphetamine OR amphetamine. Bupropion (generic Wellbutrin). For example, testing for medication adherence would necessitate lower thresholds. Substance Abuse and Mental Health Services Administration (SAMHSA). (SMA) 11-4659, DAWN Series D-35. A comprehensive literature . If it is prescribed, make sure you have the label from the pharmacy, which will show that the medication was prescribed to you. They have been shown to trigger a false positive urine result for opiates. Hows long is Valium detectable in the system? - Some legal over-the-counter drugs (such as Vicks VapoInhaler ) and some foods (such as poppy seeds) may cause a positive screening drug test. Ofloxacin has also been shown to cause a false positive test for amphetamine or methamphetamine. False positive results on urine drug tests can happen. In one study, 49 out of 50 patients taking the drug tested positive for benzodiazepines. Alcohol in hand sanitizer (from heavy use), certain liquid medications, and mouthwash or other breath cleaning products could cause you to test positive for drinking alcohol. Medically reviewed by Carmen Fookes, BPharm. in the United States, but if you consumed the tea in another country like Bolivia or Peru, you receive a positive test result for cocaine. According to one, , false positive drug tests are most commonly reported for amphetamine and methamphetamine. OTC medications that can cause a false positive for benzodiazepine include: 1. However, IA drug screens have limited sensitivity and specificity due in part to capture antibody cross-reactivity with structurally similar interfering compounds, producing false-positive results. If you think you may have a medical emergency, immediately call your physician or dial 911. Laboratory principles. This step is nonspecific in that the reaction can be caused not only by amphetamines but also by other compounds with a similar molecular structure, phentermine being a classic example. WebMD.com says between 5 - 10% of people will fail due to a false positive drug test. If I took 1/4 of a 5mg tablet in the morning and had a urine drug test that afternoon will it show positive even if only a trace? In rare cases, a false positive might occur, but it will be most likely within several hours of exposure. Common over-the-counter anti-inflammatory pain medications such as. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. 2021 Nov 30;2021:7134394. doi: 10.1155/2021/7134394. 2023 SingleCare Administrators. Careers. could cause a false positive result for amphetamines or LSD. My recommendation to anyone taking these medicines who might be drug tested is first and foremost to be honest with the tester, says Dr. McFadden. What Can Cause A False Positive For Methamphetamines, List Of Worst Foods and Drinks For Brain Health, The Benefits of Mindfulness: Sherief Abu-Moustafa Shares How To Incorporate it Into Your Life, How to Get a Medical Marijuana Card in California, How Your Blood Group Increases Your Risk Of Developing Some Diseases, WHO sends health supplies to reach 400 000 people impacted by the earthquakes in Trkiye and the Syrian Arab Republic, Longstanding WHO partners to enter into official relations with the Organization, WHO launches new roadmap on breast cancer, Celebrating World NTD day with a photo exhibit: Reframing Neglect. Additional factors such as drug interactions, dose and frequency intervals, chronic versus occasional use, and time of last ingestion can all affect the detection window. Didrex is metabolized to methamphetamine. A number of routinely prescribed medications have been associated with triggering false-positive UDS results. government site. Methamphetamine is a highly addictive and illegal psychostimulant drug that is similar to amphetamine. Urine drug testing screens for the presence of THC, the psychoactive component of marijuana, but a problem could arise due to the fact that these products are not very well-regulated and cross contamination can occur. The trazodone metabolite meta-chlorophenylpiperazine can cause false-positive urine amphetamine immunoassay results . Ferguson M, Borowiak E. Ask the Expert: False Positive Amphetamine Urine Screens. Its important to note that no drug test is 100% accurate. Epub 2017 Mar 18. A number of routinely prescribed medications have been associated with triggering false-positive UDS results, and the most commonly used tests to screen urine for drugs of abuse are immunoassays, even though false- positive results for drugsof abuse have been reported with a number of these rapid-screening products. I would counsel [anyone who received a false-positive test to ask] the administrator to do a more specific test, says Dr. McFadden, who recommends samples be sent away to labs to have a more specific mass spectroscopy assay done. yes it will show as a false positive in the drug screen urine test. International Agency for Research on Cancer - Screening Group. Quantification of urine drug levels Labetalol can also cause a false positive for amphetamine or methamphetamine because a labetalol metabolite is structurally similar to amphetamine. The potential for psychotropic medications to cause false-positive results for methadone was also evaluated. The third and final test is the methamphetamine d,l-isomer test by MS (Figure 2). Urine drug testing is frequently performed by immunoassay (IA) due to ease of use, rapid turn-around time and the ability to screen multiple drug classes. The next thing that may cause a false positive on a drug test is a vitamin B supplement . Based on a 1991 Department of Health and Human Services Technical Advisory, a d-methamphetamine level that is >20% of the total is considered indicative of a source other than an OTC product or a metabolite of selegiline. These sources could include a prescription medication or illegally manufactured methamphetamine. US Pharm. Labetalol can also cause a false positive for amphetamine or methamphetamine because a labetalol metabolite is structurally similar to amphetamine. that you have taken it.. November 25, 2008. thank you. Doxylamine (the active ingredient in Unisom) can also trigger a positive drug result for methadone, opiates, and PCP. Less commonly, antidepressants have been known to trigger false . Answer. Can poppy seeds make you fail a drug test? Brief Summary: Background: - Some legal over-the-counter drugs (such as Vicks VapoInhaler ) and some foods (such as poppy seeds) may cause a positive screening drug test. Dimetapp (Brompheniramine) What over the counter and prescription medicine show a false positive on methamphetamine tests? To cap off the list of products and foods that can cause false positive drug tests is the most unsuspecting culpritbaby soap. In general passive inhalation of crack cocaine does not cause a false-positive; however, it has been reported in cases of chronic exposure. Aripiprazole causing false positive urine amphetamine drug screen in an adult patient with bipolar disorder. False positive results for methamphetamine occur about 10 to 15 times out of 100 tests and it is usually due to one major reason, Insufficient Laboratory Tests for Confirmation, although other reasons can be added. eCollection 2022 Apr. Cross reactivity can occur with this type of testing among drugs with similar chemical structures. Small doses have central stimulant effects without significant peripheral actions. False-positive interferences of common urine drug screen immunoassays: a review. oxaprozin), which is prescribed for types of arthritis, may result in a false positive test for benzodiazepines. Know if the meds you are taking might cause a false positive and notify the administrator of the test. False-negative results 10. Updated March 15, 2021. Find out if theyre a perfect pair. Epub 2015 Dec 13. The MS confirmation test can come back with 4 possible results: 1) no amphetamines detected; 2) amphetamine only detected; 3) methamphetamine only detected; and 4) both amphetamine and methamphetamine detected (Figure 1). The drug has been linked to false-positive drug test results for. 8600 Rockville Pike Let outsiders enter, so our understanding of the strength of what medications can cause a false positive for methamphetamemes their students is very superficial. The site is secure. In very rare cases, you can have a false-positive result. Accessed April 8, 2021. could cause a false positive result for PCP or methadone. If you believe you have a failed drug test due to taking a prescription drug or consuming one of these products, you do have options. Pract Pain Manag. Positive results on urine immunoassay screening should be considered presumptive, and confirmatory testing with GC-MS should be considered to confirm the findings. While ephedra is generally considered safe, it can cause a false positive for methamphetamines on a drug test. Thats because common over-the-counter medications can result in false positives for these substances. Ranitidine. Prepared by: Additionally, it is important to note which opioids are included on an institutions standard screening, as certain opioids may require an additional order or GC-MS. Summary Baby Soap. These prescriptionsand other substancescan skew the results of a screen for illicit substances, Find out if caffeine interacts with these prescriptions for hypertension and heart problems. If other drugs with similar chemical shapes are present in the sample, this can result in a "false positive." Sustiva, Protonix, and other proton pump inhibitors can cause individuals to test positive for THC, while common antibiotics such as amoxicillin can cause a person to test positive for cocaine on certain POCT devices. However, antibodies may detect drug metabolites with similar structure and characteristcis, leading to false-positive results. If the IA test is positive, the sample is analyzed by MS to determine whether it was an amphetamine that caused the reaction. What Causes A False Positive For Methamphetamemes? Ofloxacin may also cause a false positive result for amphetamine or methamphetamine. " - Michael Lohan !!!. , and are well known to cause a false positive for amphetamines and methamphetamines.