Do all amphetamines show the same on a drug test?

Yes and no. At the first phase of drug testing, immunoassay (IA) drugs are detected by class/category and one not differentialted from the other. All amphetamines would register the same and be otherwise unidentifiable.

However, upon a non-negative finding by IA above then more precise identification can be made. More advanced technology (spectrometry) provides a unique identification.. a chemical fingerprint of previously identifed drugs, including amphetamines.

So, at one level all amphetamines do register the same, yet can be particularized by further testing.

I took a drug test (my 3rd) for probation, and have a prescription for Phentermine. Not being used to being on probation, I took a med not prescribed to me that comes up as amphetamine. Do you think they won't question it since I should test positive anyway?

I took a drug test (my 3rd) for probation, and have a prescription for Phentermine. Not being used to being on probation, I took a med not prescribed to me that comes up as amphetamine. Do you think they won't question it since I should test positive anyway?

Well just how much of the "med not prescribed to you" did you take?

Therapeutic v. levels of abuse are relatively well established.

Irrespective you have a good chance of avoiding detection because those interpreting your test are usually incapable of differentiating between a nanogram and a telegram.

Like MAYBE a total of 3 pills in 2 days.

Like MAYBE a total of 3 pills in 2 days.

We are going in a circle here.

3 pills of what? Potency?

I am always willing to provide objective authoritative information in relation to any drug test performed and the inherent capabilities thereof.

My intent and expertise is entirely dependent on information (input) provided. What you say!

You are entitled to the information requested (informed consent), I am happy to provide same, but I am not obligated to, nor will I pursue you about the neighborhood in order to collect necessary details.

If you need more precise information then provide more detailed input.

Basically, what Dr. Bill is saying is that he needs to know what the medication is that you took that was not prescribed to you. The more information you give us, the better we can assist you.

As an FYI if you are in the U.S. remember that taking medication prescribed to someone other than you is against the law and can be prosecuted. There are reasons behind this as some medications are prescribed by weight, which may be detrimental to your health if taken, as well as some meds are obtained for reasons other than what they are intended.

I am sorry. Ritalin 20 mg. Three of them in two days.

The more information you give us, the better we can assist you.

Wish I had chosen those words. J_9 expressed my thoughts more directly, in far fewer words and with greater empathy.

Nonetheless you have the attention of at least 2 qualified experts willing to address your question awaiting only further information.

I wrote this more as a senerio of what could I do. I have been diagnosed with ADD but have older meds that might not be considered within the date range of being prescribed recently enough to count. I need the meds but no money to go to doc right now (this week) for a new RX. I just need to know if they will show the same. On drug test and so maybe I could use my older meds until I get new ones next week.

Methylphenidate (Ritalin) is not tested for in any standard or extended drug panels*. Therefore should not influence the test at all. Ritalin is chemically distinct from the base amphetamine class.

That being said, there is some record of Ritalin causing a false positive for amphetamine (IA screens), but if so, would not confirm.

Basically that means that Ritalin would not have an additive effect if quantified by confirmatory testing.

*any drug can be tested for but requires a special test.