Prescription Drugs BLOG

amphetamine drug test

Drug testing is commonly practiced in the workplace. Street drugs like amphetamine can be easily detected via drug test, but what happens if someone tests positive for amphetamines when they claim to have never used the drug?

Many prescription drugs and antibiotics can yield a positive test result by cross-reacting with the reagents on the drug test panel. Some common cross-reactive drugs that can cause a false positive amphetamine test include:

Bromptons Mixture

Bromptons Mixture is one of the most common prescription drugs that can cause a positive result for amphetamines. This drug is used to treat cancer patients, so it is important to notify your Medical Review Officer before they perform a confirmation test. Otherwise, a preliminary positive result may lead to loss of employment.


Amoxicillin is used to treat infections and is a very common antibiotic. This antibiotic can easily cross-react with an Amphetamine test strip. If you are on amoxicillin and have to undergo a drug test, notify the provider that you are taking this drug. Amoxicillin is usually prescribed for ten days, but can remain in the system for many days after, which is why a prescription should be submitted prior to testing.


Ampicillin is an antibiotic similar to Amoxicillin used to treat bacterial and staph infections. A patient on penicillin should advise their healthcare provider or collector of their prescription to account for a possible false positive result. 

Over the counter drugs can yield false positive results for drugs other than amphetamine. Allergy medicine and decongestants are common triggers of false positive results. In the event of a presumptive positive found via instant drug test, a confirmation laboratory test should be performed.