here in Canada the active ingredient must be identical in identical quantity but the binding agents, excipient, and propellant are proprietary. The generics have to have the same bioavailability +-20%.In some drugs it doesn't matter, in others there is a world of difference.
I pay the 2$ it cost for brand name ventolin (my insurance cover the cost generic and I pay the difference) as the generic give asthma attack. But I would not pay one cent more for the brand name Vyvaanse. Effect wise the generic is indistinguishable (but damm the pills colors make them looks like a cheap gray market knock-off).
My wife has a paper from her oncologist for original femara because the generic made her faint a few times ( the insurance cover the whole cost because of that paper)
As a layman who fortunately has never had to deal with any "serious" medicine, how would I know which drug is good-enough is generic form, and which should be the brand name? To someone not in the know, +/-20% bioavailability sounds like a lot. Hopefully, the doctor will account for that when prescribing it, and know which way the 20% goes.
You also make it sound like 2$ isn't much to go from the generic to brand-name Ventolin. How much is too much? And is there a difference between generics of the same drug (I assume multiple manufacturers can actually produce generics) and how do you know which is better?
It’s a huge amount. I have a seizure disorder and I have to carefully increase my dosage by as much as 50% to compensate for the difference between generics and brand-name. The 20% is an average: one of the big differences between the two is absorption before/after you’ve eaten, so taking the medicine on an even slightly full stomach dramatically reduces absorption. The brand-name manufacturer now charges $300/mo for an off-patent drug you can buy generic for less than $25 (without insurance) which illustrates their view of the perceived value.
> the doctor will account for that when prescribing it
Sadly they do not. I got prescribed 12.5 mg tianeptine to take three times a day, except that amount is minuscule for my brain & body. You would think they take into account that I have fast metabolism, have many brain lesions, and so forth, but no, they do not, and there are no legal frameworks either to do so. They would have to account for these lesions in my brain for many reasons, but they do not.
Well you try the generic first, if it's does what it says on the tin, you continue the generic! Antibiotics, pain killer, antidepressants are usually not problematic.
Hopefully, the doctor will account for that when prescribin...
I never saw a doctor or pharmacist do that. Probably because you cannot predict the difference in a specific individual.
is there a difference between generics of the same drug ?
Sometimes the generic are better and yes there is a variation between manufacturers, when the pharmacy change my clonazepam supplier, I feel it. Sometimes I feel drugged out, sometime I am sleepless, but it take a few nights and then I feel the same. When that happen, I check the letter before clonazepam on bottle and systematically they changed, ex: apo-clonazepam to pms-clonazepam (the first three letters indicate the manufacturers, and I couldn't tell you which is better, just that there is a subtle difference when you switch) .
For stuff like that works on the hormonal system the difference between them is more pronounced. Like the femara, an aromatase inhibitors the block estrogen production, the brand name was significantly better for my wife but reading MBC survivors forums it's not the case for everyone. And reading those forums, it's a problem in place like the UK where the only things available is the brand NHS choosed for you.
How much is too much ?
Now about how much is too much, well it's an hard question. It depends mostly on the alternative available, there are a lot of asthma drugs so switching from generic ventolin to something else like xopenex is easy so it limits the pricing power of the original manufacturer. Thing like anticancer with a specific mechanism where no direct alternative exists, the price is significantly higher, something like 300$ a month instead of 60-80$. But for my insurance it's relatively nothing compared to the Kisquali that cost 5700$/month. They have to reauthorized it every 6 months (it's a bureaucratic formality but they don't want to pay for it if the cancer has reappear because it's useless to continue the treatment)
Note that I have something my pharmacist call a gold-plated drugs insurance. If we were only covered by Québec's public regime, my wife would probably be dead by now as they still do not reimburse Kisquali, it's suppose to change soon but I am not that informed on that because of my gold-plated insurance. (which is fucking stupid because the alternative was weekly in hospital chemotherapy that cost a lot more than 5700 a month, but then people with that treatment doesn't usually live that long so cynically it probably cost less to the system that way even)
Edit:
Why do I know that
A friend of my parents is a pharmacist and I used to ask him a lot's of questions when I was a child. Two of my female cousin (cousines in French) are pharmacists and I ask them questions on every new year day since at least the last 25 years. One practice in a drugstore, the other negotiate with the federal government for a big company that I won't name. Let's says they have a quite complementary vantage point. And I had quite the motivation to ramps up my knowledge of oncology to be the best advocate I can be for my wife.
Unfortunately pharma has the US patent office in their pocket and they release most drugs in a default form and then when the patent is running out they make a slow release version and get a new patent on it. It doesn’t take them a dozen years to figure out how to make a slow release version, and another ten to come up with an extended release version.
I’m on an extended release generic only because it’s older than dirt.
I’ve known people who claim up one side and down the other that Advil is more effective than generic ibuprofen and it’s thought to be down to the other ingredients. I had at one point convinced myself of this as well, but these days even Advil doesn’t always help. Bummer is that only a couple of CBD products do anything for me either. May be why I’m so grumpy.
In my experience as a medically complicated person, generics generally work, but may have different side effects, both in scale and style. One of the worst was a duloxetine generic that came on so hard and strong that I felt serontoninised.
My friend the John the Pharmacist explained that the binders etc can accelerate absorption. His advice was be careful the first two days of a new generic formulation.
I would assume the NHS (like the TGA here in Oz) looks _very_ carefully at the side-affect profile before they buy any particular generic. Government agencies tend to try not to poison voters.
I take dimethyl-fumarate, which is a serious medication for MS, but sadly ever since "Tecfidera" got withdrawn for some reason, I can only get a "shittier" generic. That said, side-effect profile appears to be the same, thankfully. All in all, I think they are "almost" identical, if not identical.
I’ve had decent luck with slow release generics, but they go out of their way to make SR generics take a quarter of a human lifetime to come out after the original is available.
I have sent in drug samples for testing, in my case they were name brand.
Variance per dose is about plus/minus 15% across the board. You might get 9mg one day, and 11.5mg another for a drug with a nominal 10mg label. Injectables are typically better than oral tablets it seems but not by a lot.
Purity was pretty good though, it was mostly a dosing variance I saw.
I pay the 2$ it cost for brand name ventolin (my insurance cover the cost generic and I pay the difference) as the generic give asthma attack. But I would not pay one cent more for the brand name Vyvaanse. Effect wise the generic is indistinguishable (but damm the pills colors make them looks like a cheap gray market knock-off).
My wife has a paper from her oncologist for original femara because the generic made her faint a few times ( the insurance cover the whole cost because of that paper)