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Dr. Bob is Robert Hsiung, MD,
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Posted by yxibow on January 6, 2007, at 23:20:34
In reply to Generics » linkadge, posted by ed_uk on January 6, 2007, at 16:45:45
> Hi Link,
>
> >So, generics are allowed to be as much off as +/- 20%?
>
> >If you were taking 375mg of effexor, you could have as much as much as 150mg difference between two doses.
>
> No, the amount of drug in a generic tablet/cap will be almost identical to the amount of drug in a branded tablet/cap. When comparing a new generic product to the orginal branded product, bioequivalence studies are performed. In the UK, the following criteria are assessed:
>
> Product A = the test product ie. the new generic
> Product B = the reference product ie. the original brand
>
> A group of volunteers are given the medication. Pharmacokinetic parameters (AUC, Cmax and Tmax) are determined for each product (A and B). The ratio of A/B for AUC and Cmax and 90% geometric confidence intervals for AUC and Cmax respectively are determined. These values must fall within the accepted regulatory range of 80-125% (0.80-1.25 range) to indicate that A is bioequivalent to B.
>
> EdYou can go to Drugs@FDA and search around for the generic table, I dont remember offhand but I think I posted something about it in the past -- we do the same AB for generics. Most generics are labeled as AB.
The important thing is not the hue and cry over generics being different than the expensive "original" -- which I understand -- its that if your insurance is much cheaper for the generics, insist that your pharmacy start you on a particular brand of generic -- typically like for the benzodiazepines there can be half a dozen -- and keep you on it and inform you if there are changes. Also remember, and this may sound mean spirited, but there is a placebo effect knowing that you are getting a different generic or are being switched off to a generic. That very knowledge can cause subtle changes especially in affective/anxiety disorders to fool the mind into thinking that their medication is no longer working. I'm not saying it can't be the case -- as Ed was explaining about the AUC curve, but for medications like long half life benzodiazepines, its really should not be an issue to take a generic -- Klonopin is at least 16 hours and Valium is more than 24 hours.
Now there are a few medications, biologicals, a few rare antibiotics, insulin, synthroid, etc, that are not AB rated. Those are I think by decree to be have to have a closer tolerance, original or not. Don't quote me on that but I believe it is the case.
-- Jay
Posted by Quintal on January 6, 2007, at 23:50:15
In reply to Re: Generics » ed_uk, posted by yxibow on January 6, 2007, at 23:20:34
My old psychiatric nurse once asked a psychopharmacologist (the much maligned Prof. Heather Ashton no less) for her opinion on the old generic vs. brand debate. It was her personal opinion that there was a difference and it was probably due to the different binders and colorants used by the companies as well as variable amount of active ingredient. She stressed that this was just her personal opinion and there was no empircal evidence to support it though. That said, my psychiatric nurse saw a lady who only responded to one particular make and it wasn't the brand name Prozac, it was the generic 'Dr. Reddy's' fluoxetine. If a person responds well to a generic they should make sure they stick to that particular brand and not accept any other generic if possible. My guess is that generic drugs produced by the same company will be fairly reliable at giving a consistent dose of active ingredient but switching between brands could be a problem.
I've rarely used brand name drugs at all, and if I have it's simply because there isn't a generic available, not that I have much choice in any case.
Q
Posted by laima on January 6, 2007, at 23:54:44
In reply to Re: Generics » yxibow, posted by Quintal on January 6, 2007, at 23:50:15
Perhaps then the various generic companies dinker with the recipees a bit- that's still unfair, but it's not like each pill in the bottle is different. On the other hand, I vaguely remember hearing somewhere that the companies who make the brand name drugs are under greater FDA scrutiny, and that the generic companies are more often left alone. But it doesn't make sense, so I don't know if it's true.
Posted by blueberry1 on January 7, 2007, at 2:35:25
In reply to Re: Generics » LlurpsieBlossom, posted by Phillipa on January 6, 2007, at 22:52:54
To make peanut brittle sugar needs to be heated to just the right temperature for just the right amount of time. Slight minor variations will still produce the brittle, but the brittle will be different...maybe a little softer, a little harder, a little darker, a little lighter, different stomach absorption times, and the taste is different...even though it is still just the same original sugar molecules.
Are the generic vs brand recipes exactly the same? I mean, times, temperatures, fillers, everything? If they aren't, then it makes me wonder how they could be identical end products. Very close for sure. But identical? I think there is enough difference that people can tell. Maybe some are placebo but my hunch is most are real.
Posted by LlurpsieBlossom on January 7, 2007, at 5:18:44
In reply to Re: Generics, posted by blueberry1 on January 7, 2007, at 2:35:25
What about if the active ingredient must have a particular configuration, for instance an enantiomer? I guess lexapro and celexa are the same molecules, but lexapro is only one enantiomer, whereas celexa is a blend of both.
from the earlier posts though, I thought that the key factor is how the human body reacts to drug A vs drug B, not about how a chemical analysis finds that they are similar or different?
anyways...
Phillipa youre 100 because youre special. like an A+ :)
Ll
Posted by ed_uk on January 7, 2007, at 7:27:28
In reply to Re: Generics, posted by blueberry1 on January 7, 2007, at 2:35:25
Hi Blueberry
>Are the generic vs brand recipes exactly the same?
Sometimes yes, sometimes no. In some cases, the 'generic' is simply the branded product repackaged into a different box. For example, in the UK, generic fexofenadine (a popular antihistamine) has just been introduced. Although this 'generic' is much cheaper than the Telfast brand, opening the box will soon reveal that this 'generic' is simply Telfast in a cheaper looking box. The companies which make the 'name brand' often supply the generic companies with product. This is especially true when 'name brand' companies have a branch of the companies which supplies generics eg. Sanofi Aventis has a generic arm called Winthrop Pharma.
Some more examples......
TEVAs 'generic' rampril tablets are actually Tritace tablets!
Winthrop's 'generic' alfuzosin 10mg tablets are actually Xatral XL.
Generics UK's lofepramine 70mg tablets are actually Gamanil.
A cheap UK brand of co-codamol 30/500 tabs (I forgot the company) is actually
Winthrop's zolpidem tablets are actually Stilnoct (Ambien).
It's funny how much cheaper these 'generics' are, despite them being identical to the brand :)
Ed
Posted by ed_uk on January 7, 2007, at 7:42:41
In reply to Re: Generics » yxibow, posted by Quintal on January 6, 2007, at 23:50:15
Hi Q
>If a person responds well to a generic they should make sure they stick to that particular brand and not accept any other generic if possible.
......if they pharmacy will allow. In the UK, the system of payment to pharmacies relies on the fact that the pharmacy can choose which generic they use. The £6.65 prescription charge goes to the government, not the pharmacy, and does not cover the cost of the medication. The pharmacy is paid a fixed price by the government for a particular medication eg. fluoxetine 20mg caps, regardless of which generic they dispense. Because different generics vary in price, they pharmacy may refuse to dispense a particular generic if it is too expensive because they would loose a lot of money. Of course, if the patient receives a private prescription and are paying for the medication out of pocket, they can receieve any brand which they want.
GPs are not allowed to demand specific generics (eg. TEVA, Alpharma, Generics UK) on NHS prescriptions. It is up to the pharmacy which generic they give. GPs are, however, allowed to prescribe branded products on the NHS eg. they could prescribe Prozac 20mg caps. In this case, they pharmacy will dispense the brand, often as a European Import. European Imports are used widely in UK community pharmacy because the government pays pharmacies based on the assumption that European Imports will be used. Because of this, the pharmacy will loose money if they dispense the 'English' brand.
Although GPs *can* prescribe drugs by brand eg. Prozac instead of fluoxetine, this practice is strongly discouraged because it wastes vast amounts of NHS money, something which the cash-strapped NHS can ill afford. In short, if people want brands on the NHS, taxes will have to go up!.........a lot!!
Regards
Ed
Posted by ed_uk on January 7, 2007, at 7:45:23
In reply to chiral molecules?, posted by LlurpsieBlossom on January 7, 2007, at 5:18:44
Hi L
>What about if the active ingredient must have a particular configuration, for instance an enantiomer? I guess lexapro and celexa are the same molecules, but lexapro is only one enantiomer, whereas celexa is a blend of both.
The generic will be produced to match the brand. Like Celexa, generic citalopram is a racemate. When generic escitalopram is eventually introduced, it will be a single enantiomer, like Lexapro.
Regards
Ed
Posted by LlurpsieBlossom on January 7, 2007, at 9:40:51
In reply to Re: chiral molecules? » LlurpsieBlossom, posted by ed_uk on January 7, 2007, at 7:45:23
I was just curious about this for molecules for which the effects of different enantiomers has NOT been studied.
like, maybe seroquel is a mix of one active and one inactive enantiomer. The company producing seroquel has a precise way that they do the reactions, which they dont share with their generic competitors. The generic chemists come up with a set of reactions that produces the same molecule, but the racemic mixture contains different ratios of the active vs. inactive enantiomer.
maybe some people respond to one species and others respond to another.
anyways... Am I correct that it is tricky to analyse the composition of enantiomers in a racemic mixture? Maybe its a piece of cake for the professionals. I just remember that this was a notoriously tricky thing back in my days as a chemistry student...
ciao
Ll
Posted by ed_uk on January 7, 2007, at 10:03:41
In reply to Re: chiral molecules? » ed_uk, posted by LlurpsieBlossom on January 7, 2007, at 9:40:51
Hi L
I don't think the generics companies always manufacture the drug substance, they often just make the tablets etc. AFAIK, the source of the drug itself is sometimes the same for both the brand and the generic.
Manuafacturing racemic drugs (eg. citalopram) which consist of 50% R-enantiomer and 50% S-enantionmer is probably relatively basic. The manufacture of single-isomer products such as escitalopram is technically more challenging.
Regards
Ed
Posted by naughtypuppy on January 7, 2007, at 10:58:18
In reply to Re: chiral molecules? » LlurpsieBlossom, posted by ed_uk on January 7, 2007, at 10:03:41
Perhaps the coating/fillers have something to do with the point in the digestive system that the active ingredient is most readily absorbed. Something like Depakote which is absorbed in the small intestine since stomach acids break it down. Or like time released capsules.
Posted by notfred on January 7, 2007, at 12:23:01
In reply to Re: chiral molecules?, posted by naughtypuppy on January 7, 2007, at 10:58:18
> Perhaps the coating/fillers have something to do with the point in the digestive system that the active ingredient is most readily absorbed. Something like Depakote which is absorbed in the small intestine since stomach acids break it down. Or like time released capsules.
>
That is the major difference between brand and generic. The actives remain the same, and often made by the brand manufacure. In any case lorazepam is lorazepam is lorazepam no matter who made it.coatings/fillers/binders effect how much drug is taken up by the system. You cannot just take the raw active compound and expect to absorb it properly. There is a lot of science in delivering and absorbing the drug into the body. This is where the differences between generic and brand play out, if any.
Posted by ed_uk on January 7, 2007, at 13:20:14
In reply to Re: chiral molecules?, posted by notfred on January 7, 2007, at 12:23:01
>There is a lot of science in delivering and absorbing the drug into the body.
Definitely. Some generics have an identical formula to the original brand, whereas others have different excipients.
Ed
Posted by ed_uk on January 7, 2007, at 13:29:05
In reply to Re: chiral molecules?, posted by naughtypuppy on January 7, 2007, at 10:58:18
Hi
As an example, here is a graph which was produced when determining whether Dr. Reddy's lamotrigine generic was bioequivalent to the original brand: Lamictal..........
http://www.mhra.gov.uk/home/idcplg?IdcService=GET_FILE&dID=25158&noSaveAs=0&Rendition=WEB
Open the link and scroll down to page 14.
The x-axis shows time. The y-axis shows the drug level in the blood.
As you can see, the two formulations are very close. Dr. Reddy's generic appears to produce very slightly higher blood levels than Lamictal, but this may just be due to chance.
Ed
Posted by Quintal on January 7, 2007, at 15:15:08
In reply to Re: Generics » Quintal, posted by ed_uk on January 7, 2007, at 7:42:41
>GPs are not allowed to demand specific generics (eg. TEVA, Alpharma, Generics UK) on NHS prescriptions. It is up to the pharmacy which generic they give. GPs are, however, allowed to prescribe branded products on the NHS eg. they could prescribe Prozac 20mg caps. In this case, they pharmacy will dispense the brand, often as a European Import. European Imports are used widely in UK community pharmacy because the government pays pharmacies based on the assumption that European Imports will be used. Because of this, the pharmacy will loose money if they dispense the 'English' brand.
I think I've read they are allowed to specify a specific brand for anticonvulsants for epileptics because of the danger small differences can cause. The same with lithium.
It amuses me to hear of people being so fussy over brand names - my lamotrigine tablets were often an amalgam of obscure foreign brands. I sometimes got a supply of Spanish children's orodispersible tablets and they were sometimes mixed in with a few brand name Lamictal tabs to fill the same prescription.
>Although GPs *can* prescribe drugs by brand eg. Prozac instead of fluoxetine, this practice is strongly discouraged because it wastes vast amounts of NHS money, something which the cash-strapped NHS can ill afford. In short, if people want brands on the NHS, taxes will have to go up!.........a lot!!
Yes, and not all will respond best to the original brand name in any case. Some people respond better to one of the generics. As you have shown, sometimes the generic can produce higher blood levels than the brand name.
Q
Posted by notfred on January 7, 2007, at 15:48:00
In reply to Graph comparing Lamictal brand to new UK generic, posted by ed_uk on January 7, 2007, at 13:29:05
Thanks Ed, nice to have it in black and white.
Is PhEur comparable to USP ? What do you know about EEC, does is compare to USP ?
Posted by ed_uk on January 7, 2007, at 16:04:50
In reply to Re: Generics » ed_uk, posted by Quintal on January 7, 2007, at 15:15:08
Hi Quinty
>I think I've read they are allowed to specify a specific brand for anticonvulsants for epileptics because of the danger small differences can cause. The same with lithium.
In the UK, GPs can prescribe any drug by brand (except a few 'banned' brands such as Xanax). In this case, the pharmacy will always dispense the branded product, often as a European import. What GPs can't do is prescribe a generic and specify which generic is dispensed. If the prescription states the generic name, the pharmacy can dispense any generic. Doctors are encouraged to prescribe most drug generically, except lithium and a few others.
The situation in hospital pharmacy is different. NHS hospital doctors cannot prescribe drugs by brand. If they do, the pharmacy will simply substitute a generic.
>It amuses me to hear of people being so fussy over brand names - my lamotrigine tablets were often an amalgam of obscure foreign brands. I sometimes got a supply of Spanish children's orodispersible tablets and they were sometimes mixed in with a few brand name Lamictal tabs to fill the same prescription.
The Spanish lamotrigine was probably Crisomet. I've seen that one a few times. European imports are regulated and licensed by the MHRA. All imports are branded products produced by international pharmaceutical companies, and are equivalent to the 'English' brands. Imported brands will always be sourced within the EU, generally from Spain, Greece or Italy - where drugs are less expensive due to government-enforced price controls. The original packaging is 'overlabelled' in English, and an English patient information leaflet is inserted.
Regards
Ed
Posted by ed_uk on January 7, 2007, at 16:18:27
In reply to Re: Graph comparing Lamictal brand to new UK gener, posted by notfred on January 7, 2007, at 15:48:00
Hi NF
PhEur stands for European Pharmacopoeia. It is similar to USP. Although the British Pharmacopoeia (BP) is still in use, the European Pharmacopoeia is now a lot more important.
>What do you know about EEC?
I think it's referring to the European Union Directives on excipients.
Regards
Ed
Posted by Phillipa on January 7, 2007, at 17:27:45
In reply to Re: Generics, posted by blueberry1 on January 7, 2007, at 2:35:25
I know that greenstone xanax is the original xanax my pharmacist told me not to spend the money on the real xanax and he was right even the taste is identical. Same company half for generics half the real deal. Love Phillipa
Posted by Quintal on January 7, 2007, at 18:31:59
In reply to Re: Generics » blueberry1, posted by Phillipa on January 7, 2007, at 17:27:45
>I know that greenstone xanax is the original xanax my pharmacist told me not to spend the money on the real xanax and he was right even the taste is identical.
You actually taste your Xanax Phillipa?! It was one of the most bitter chemicals I've ever put in my mouth. Valium is just as bad if heaven forbid, it dissolves on your tongue before you can wash it down. Klonopin was OK though - a bit peppery.
Q
Posted by Phillipa on January 7, 2007, at 19:30:50
In reply to Re: Generics » Phillipa, posted by Quintal on January 7, 2007, at 18:31:59
Quintal I lost my taste and smell almost three years ago but the taste buds distinguish bitter, sour, sweet, and salty. So I can taste the xanax but not lunesta. Love Phillipa ps I google autoimmune diseases and discovered loss of taste is one and I do have the hasimotos.
Posted by valene on January 8, 2007, at 18:04:48
In reply to Re: Generics » ed_uk, posted by yxibow on January 6, 2007, at 23:20:34
Jay,
Generic difference is real - I had a bad batch of Sandoz xanax from my pharmacy and was getting withdrawal symptoms on my regular dose - thought I had Tolerance withdrawal!!! Didn't !!
I finally got the name brand xanax, then switched to greenstone brand, and I've been fine ever since. In fact here is proof that the sandoz bottle of pills was not as strong:: I filled my pill case one day and unknowingly took the pills out of the sandoz (no good) bottle. That day I had startle at loud noises, head pressure excess anxiety, all the symptoms of withdrawal, WITHOUT knowing I had taken the wrong pills. When I took my 6pm dose, I happened to examine the pill and saw the little marks on the pills that SANDOZ uses, NOT Greenstone! So I knew immediately I had switched the pills by mistake. I threw the bad ones out and have not had one shred of "tolerance" withdrawal since!! Proof enough for me.
Val
Posted by yxibow on January 9, 2007, at 3:17:02
In reply to Re: Generics » yxibow, posted by valene on January 8, 2007, at 18:04:48
> Jay,
>
> Generic difference is real - I had a bad batch of Sandoz xanax from my pharmacy and was getting withdrawal symptoms on my regular dose - thought I had Tolerance withdrawal!!! Didn't !!
>
> I finally got the name brand xanax, then switched to greenstone brand, and I've been fine ever since. In fact here is proof that the sandoz bottle of pills was not as strong:: I filled my pill case one day and unknowingly took the pills out of the sandoz (no good) bottle. That day I had startle at loud noises, head pressure excess anxiety, all the symptoms of withdrawal, WITHOUT knowing I had taken the wrong pills. When I took my 6pm dose, I happened to examine the pill and saw the little marks on the pills that SANDOZ uses, NOT Greenstone! So I knew immediately I had switched the pills by mistake. I threw the bad ones out and have not had one shred of "tolerance" withdrawal since!! Proof enough for me.
>
> Val
Do you know who owns Greenstone?I'll give you a guess. They made Neurontin.
What is the most commonly available generic Neurontin that I've seen? Greenstone.
Oh, yes, Pfizer.
http://www.pfizer.com/pfizer/subsites/counterfeit_importation/mn_pharmacist_greenstone.jsp
Bought 'em up in 2003.
I'm sorry to hear you had trouble with a "batch" of generic Xanax, but there are like half a dozen that do make it. One of the problems there is that if you do not stick with a particular brand, and there is a chance of bad batches with any brand, including the "original" or the patent extending XR, a drug with such a short half life can wreak havoc on the system. Its why alprazolam really should be a PRN medication, but I understand that there are those who respond only to it and not other benzodiazepines.Drugs@FDA does not list Greenstone as a maker although they may be a subcontractor.
-- tidings
Posted by valene on January 9, 2007, at 14:33:02
In reply to Re: Generics » valene, posted by yxibow on January 9, 2007, at 3:17:02
> Do you know who owns Greenstone?
>
> I'll give you a guess. They made Neurontin.
>
> What is the most commonly available generic Neurontin that I've seen? Greenstone.
>
> Oh, yes, Pfizer.
>
> http://www.pfizer.com/pfizer/subsites/counterfeit_importation/mn_pharmacist_greenstone.jsp
>
> Bought 'em up in 2003.
>
>
> I'm sorry to hear you had trouble with a "batch" of generic Xanax, but there are like half a dozen that do make it. One of the problems there is that if you do not stick with a particular brand, and there is a chance of bad batches with any brand, including the "original" or the patent extending XR, a drug with such a short half life can wreak havoc on the system. Its why alprazolam really should be a PRN medication, but I understand that there are those who respond only to it and not other benzodiazepines.
>
> Drugs@FDA does not list Greenstone as a maker although they may be a subcontractor.
>
> -- tidings
>
And did you realize that Pfizer bought out Upjohn, the original manufacturer of Xanax? Interesting. Perhaps alpraz. *should* be a prn med. but I find that I go about 8-10 hours between doses usually, so it works quite well for me personally and also has a bit of an antidepressant effect. Dr. Salzman from Harvard wanted me to stay on it when I consulted him at my pdoc's request. I do wish to lower the dosage to 1mg. if possible though. I have taken it for 20+ years! Highest was 3mg now 1.75mg. daily.Val
Posted by Phillipa on January 9, 2007, at 18:41:04
In reply to Re: Generics, posted by valene on January 9, 2007, at 14:33:02
And greenstone is a good med. Tried the other generics big difference. And a lot of pdocs say to take a certain generic as their experience shows which ones the patients respond best to. Love Phillipa
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