Cross-reacting medications for Amphetamines

Cross-reactants are molecules which are very similar to the substance being tested for. When someone has consumed these recently, there is the chance that it will show as a false positive result.

Discovering these tends to be a case of trial and error – it can be hard to predict beforehand whether any given substance will cause issues.
There aren’t many cross-reactants, compared to the infinitude of medications and substances available to consume!

Here’s a list of medications that can give false positive readings for amphetamines. Most of these are fairly rare, and some of these have been withdrawn and are no longer available legally.

  • Buflomedil, used for treating artery disease. Brand name Loftyl.
  • Brompheniramine, an antihistamine. Brand name Dimetapp.
  • Chlorpromazine, used to treat psychosis, severe depression, and nausea. Brand names Thorazine and Largactil.
  • Fenfluramine, an amphetamine derivative used to treat seizures. Brand name Fintepla.
  • Isometheptene, used to treat migraines. Brand names Amidrine and Nodolor.
  • Mexiletine, used to treat abnormal heart rhythms and chronic pain. Brand names Mexitil and NaMuscla.
  • A metabolite of procainamide, which is used for the treatment of cardiac arrhythmias. Brand name is Procainamide.
  • Perazine, used to treat psychosis. Generic drug.
  • Phenmetrazine, used to suppress appetite and also as a stimulant. Withdrawn from the market, as it was widely abused. As an example, in 1963 Lee Harvey Oswald was in custody for the assassination of JFK. A nightclub owner named Jack Ruby walked to the police headquarters and shot Lee Harvey Oswald, who died within a few hours. Jack Ruby was on phenmetrazine at the time!
  • Phentermine, a weight loss medication which is also a form of amphetamine. Brand name Ionamin.
  • Phenylpropanolamine, a decongestant. Brand names Proin, Propalin, Cystolamine, Uricon and Uriflex-PT.
  • Promethazine, an antihistamine. Brand name Allersoothe.
  • Quinacrine, anti-malarial and also used to treat some skin conditions. Brand names Mepacrine and Atabrine.
  • Ranitidine, used for treating reflux. Brand names Zantac, Ranitidine and Peptisoothe.
  • Tolmetin, an anti-inflammatory drug. Brand name Tolectin.

There is nothing certain about any of the above. When in doubt, ask for advice and send the sample to a laboratory for confirmation testing.

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Responses to questions: Vulcan Steel court case, 2021

A reader asked, in response to a prior newsletter email about the Vulcan Steel court case, regarding their drug testing policy:

How can a drug testing policy be both not specific enough, as well as being too prescriptive? It’s either one or the other!

We’re glad you asked.

A drug testing policy should be both specific and focused.

Specific means that it’s clear what we are going to do, and we state exactly that in the policy. No vague terms, no unclear directions, no ambiguous consequences.

An example of an unspecific policy (borrowing from last week):
Drug testing will utilise hair and/or urine and/or saliva test techniques, as outlined in the DASP.

An example of a specific policy:
Urine drug testing will utilised for pre-employment, random, and rehabilitation, and oral fluid drug testing for post-incident and reasonable cause drug testing.

Focused means that the policy strips out everything that’s irrelevant or unnecessary. The exact mechanics of our drug testing process is very interesting, but it’s not relevant or necessary for the policy. A (very) high level overview will serve fine.

An example of an unfocused policy:
Random drug testing will be drawn from a pool of employees on site. A number shall be assigned to each employee, and written down on a piece of paper. The pieces of paper will be put into a bag and shaken. 5 pieces of paper will be drawn out and the employees those numbers correspond with will be drug tested. The drawing will be done in the presence of a union representative.

An example of a focused policy:
Employees shall be selected randomly for random drug testing.

This is fairly easy to achieve if you separate your drug testing policy from your procedures, instead of combining the two.

Newsletter archive

This is an archive from the Sober Check newsletters, which are sent out every week.
Sign up to the newsletter to receive these as they come out.