I just read in a newspaper about this new drug that’s supposedly a hundred times stronger than heroin. Given that heroin is pretty durned strong (as far as I know), this sounds implausible to me. What does it mean in real terms? How do you measure the strength of drugs anyway? Is it like toxins, where you see how much you need to kill a certain percentage of a certain amount of mice within a certain time frame? Do you see how much you need to get thirty mice seriously high, or what?
I would guess it means much it takes to get intoxicated. So for instance you might need 100 milligrams of heroin to get high, but only 1 milligram of another drug. You could then say that the other drug is 100 times stronger than heroin
That sounds somewhat like what I expected. But how do you measure this? Where does the line go between “sober” and “intoxicated”?
The strength would be the pain relieving property, which is easier to determine experimentally than intoxicatation, which is more subjective.
The strength may be for oral or intramuscular administration.
This site details pain measurement.
Whoops, I was unclear. I’m not talking about pharmacological drugs, but only narcotics like heroin, cocaine and the like. Or do all of these relieve pain? If they do, is that really the relevant measure of strength, since junkies hardly take them to escape physical pain?
First, drugs are drugs. Many can be abused and also have medicinal uses.
Cocaine is a central stimulant as well as a local anaestheic.
Heroin, codeine, morphine, pethedine are all strong opioid analgesics. These drugs act on pain receptors. They mimic endogenous opiod chemicals which act on opioid receptors to produce analgesia, respiratory depression, euphoria and sedation.
The problem with these medicines is that they are attractive to addicts because of the ‘buzz’. Especially when taken intravenously.
Weak opiods, like codeine, are not as strong. If you administer more the side effects are detrimental. Weak opiods are less likely to lead to dependence.
The strength of pharmaceutical drugs, at least oral, anal and transdermal ones is measured by the speed at which they release the active ingredient in an in-vitro dissolution test, which is designed to simulate the process of the assimilation of the active component of the dosage form into the body.
These tests are a crucial part of the QC lab’s.
Illegal drugs, by definition, have no QC work done on them, require no cert of analysis and the production process has no FDA or Medicine Board auditors, and so are only tested by interested parties, such as those who work in drug awareness schemes. The police do not commission it, as the forensic team generally only have to identify the drug and how much of it there is, not its pharmacological effects.
For a newspaper to claim that some new street drug is 100 times more potent than some other street drug, I would think that they or some of the drug addiction charities commissioned a consultancy lab to set up a series of dissolution tests, similar to the ones which are routine in the pharmaceutical industry, as outlined above.
If they did that, they are testing this new drug against the old drug. But it would depend as well on the purity of both samples, under controlled circumstances. A street drug will be mixed with any and all kind of dross, any component of which can accelerate or hinder the absorption of the active into the user or change the active into something else entirely. Some of the filler dross will have no effect whatsoever on the absorption process. That is a big can of worms and a different question.
So the best that they can say is that under standardised and contolled laboratory conditions, based on dissolution tests, 100% pure Street Drug A is released into the bloodstream at a rate of x microgram/mL/min and 100% New Stronger Street Drug B is released at 100x microgram/mL/min.
So B is stronger than A.
Thanks, curly chick. That answers my question.
It might, if it weren’t completely wrong. First of all, heroin, like many street drugs, is injected – dissolution testing (normally run on tablets is not done on injectables. It’s completely irrelevant to the question. It’s also irrelevant because the question involves the physiological potency of the drug substance. Dissolution rate and bioavailability (which I think must be what you mean, although you don’t appear to know the difference) are properties of a drug dosage form.
Illegal drugs “by definition” have no QC work? Poppycock. Many illegal drugs are professionally manufactured and QC-ed before being diverted to illegal use. Even those illegal drugs in Schedule I (those having ‘no legitimate medical use’) were legal at one time, and virtually all were thoroughly tested at that time – heroin being a classic example.
We know, thoroughly, the physiological properties of heroin; we know the typical analgesic dose, we know the LD-50, we know how much your average junkie takes to get a buzz. If the dose necessary to get to one of those points with a new drug is 1% of the heroin dose, then it’s “100 times as potent.”
We don’t know what the drug is, what the physiological standard is (death, analgesia, etc.), whether they’re even the same sort of drug, or whether the reporter or his source had any idea what he was talking about. We do know that dissolution tests are irrelevant to the discussion.