At the present moment there are about 65% of medications that can cause false positive drug test results – the data is based on on the basis 161 prescription and over the counter medications studied in the course of the research carried out by Los Angeles Times New Service.
As a matter of fact, such results most commonly show up in urine test as it is the most frequent drug test/screen option used by employers.
In accordance with the data of Byrd Labs there are more than 250 over-the-counter medications and prescription drugs that can cause false positive drug test results. Here are some of them.
Substances/Conditions that can cause false positives for THC:
- Dronabinol (Marinol)
- Ibuprofen; (Advil, Nuprin, Motrin, Excedrin IB etc)
- Ketoprofen (Orudis KT)
- Kidney infection (Kidney disease, diabetes) Liver Disease
- Naproxen (Aleve)
- Promethazine (Phenergan, Promethegan)
- Riboflavin (B2, Hempseed Oil)
Substances/Conditions which can cause false positives for Amphetamines:
- Ephedrine, pseudoephedrine, propylephedrine, phenylephrine, or desoxyephedrine
(Nyquil, Contact, Sudafed, Allerest, Tavist-D, Dimetapp, etc)
Phenegan-D, Robitussin Cold and Flu, Vicks Nyquil
- Over-the-counter diet aids with phenylpropanolamine (Dexatrim, Accutrim)
Over-the-counter nasal sprays (Vicks inhaler, Afrin)
Asthma medications: (Marax, Bronkaid tablets, Primatine Tablets)
- Prescription drugs: (Amfepramone, Cathne, Etafediabe, Morazone,phendimetrazine, phenmetrazine, benzphetamine, fenfluramine, dexfenfluramine,dexdenfluramine,Redux, mephentermine, Mesocarb, methoxyphenamine, phentermine,amineptine, Pholedrine, hydroymethamphetamine, Dexedrine, amifepramone, clobenzorex,fenproyorex, mefenorex, fenelylline, Didrex, dextroamphetamine, methphenidate, Ritalin,pemoline, Cylert, selegiline, Deprenyl, Eldepryl, Famprofazone) Kidney infection, kidney disease, Liver disease, diabetes.
Substances/Conditions which can cause false positives for Opiates:
- Poppy Seeds
- Tylenol with codeine
- Most prescription pain medications
- Cough suppressants with Dextromethorphan (DXM)
- Kidney problems
- Diabetes, Liver Disease
Other Conditions that can cause false positives:
- Kidney infection (kidney disease)
- Liver infection (liver disease)
- Amoxicizlin, tonic water
Among the items reported as causing false positive test results are also the following ones:
- Pain relievers such as Advil, Nuprin, Motrin and menstrual cramp medications like Midol and Trendar. All medications that contain Ibuprofen are known to cause positive samples for Marijuana. Naproxyn is known to have cross reacted in blind tests. The latter is usually prescribed to runners, sports injuries to joints, and those suffering from arthritis.
- Most common nasal decongestants can cause a positive reading for Amphetamines. As the cross reactive list suggests at the back of this booklet, amphetamine false positives are the most common.
- Vicks Formula 44M containing Dextromethorphan, and Primatene-M containing perylamine as well as the pain reliever Demerol, and prescription anti-depressant Elavil test positive for opiates up to three days.
- Quinine water can also cause a positive reading for opiates.
- Poppy Seeds such as the ones on a bagel from your favorite deli, etc. The journal of Clinical Chemistry Vol.33 No.6, 1987 reports: “the quantities of poppy seed ingested in this study (25 and 40 g) may be expected to be contained in one or two servings of poppy seed cake. Therefore, poppy seeds represent a potentially serious source of falsely positive results in testing opiate abuse.”
Nyquil Nighttime Cold Medicine is able to test positive for Methadone up to 2 days.
- Antibiotics – especially some newly developed ones are able to cause positive samples urine tests.
- Diazepam tests positive for PCP as well as the ingredient in some cough medicines, Dextromethorophan.
- A person’s own enzymes. There is a number of people who can produce certain enzymes in their urine that can cause a positive drug test result.
- Passive marijuana inhalation – the smoke that you inhale by standing next to someone else may give your test a positive result for several days.