Can you fail a drug test if you don't use drugs?

Answer 1

Yes, many substances can lead to false positives. I have heard of cases where valerian root will trigger a false positive for benzodiazepines, cold medicine has triggered a false positive for amphetamines or PCP, and poppy seeds are known to cause a false positive for opiates. Many prescription medications can also lead to false positives.

Answer 2

In depth review of drugs that cause false positives

Amphetamine/Methamphetamine

The active chemical of some medication will be metabolised to amphetamine, this will cause positive amphetamine/methamphetamine test results. Eg Adderall contains a mixed amphetamine salt widely prescribed as a psycho-stimulant medication for attention deficit hyperactive disorder, or ADHD, or ADD, and use of such medication would cause a positive amphetamine test.

In 2002 the Food and Drug Administration in the USA approved eye drops which contained hydroxyamphetamine and tropicamide. Although amphetamine is metabolised to hydroxyamphetamine, hydroxyamphetamine is not metabolised to amphetamine. Therefore, use of such products should not cause a positive (non-negative) amphetamine test result.

Drugs that may cause false positive to amphetamines include,

Diet pills (Amfepramone, Amphetaminil, Clobenzorex, Benzphetamine, Fenfluramine, Fenproporex, Mefenorex, Obetrol, Phentermine)

Attention deficit disorder medication (Ritalin, Dextroamphetamine, Adderall, Benzedrine, Pemoline, Pemoline)

Cold medication (pseudoephedrine (old sudafed), Vick’s Inhaler, Promethazine, Allerest, Bromphenlramlne, Dimetapp (loratadine), Efidac, Phenylephrine, Sinarest)

Antidepressants (Bupropion, Fluoxetine)

Blood pressure tablets (Labetalol)

Asthma medication (Inhalers, Ephedrine, Primatene-M, Tedral)

Antidepressants (Wellbutrin, Desipramine, Selegiline, Trazodone)

Parkinson’s disease medication (Amantadine, Deprenyl, Eldepryl)

malaria treatment (Chloroquine)

Schizophrenia Medication (Chlorpromazine, Fluspirilene, Quetiapine)

Anti-inflammatory (Famprofazone)

Eye drops with Pholedrine

High blood pressure medicine (Labetalol, Procainamide)

Antihistamine (Mepyramine, Phenegan-D)

Gastroesophageal reflux disease medication (Ranitidine)