This will be a dumb question

[cbrons]

Before I went to medical school, I worked as a pharmacy tech at Walgreens. While I was there, I remember several patients on a variety of different medications swearing by a certain generic brand... basically asserting that one generic brand worked better or had fewer side effects than another. I always thought the FDA mandated that all generic drugs be chemically identical, but the truth is that is just an assumption I made and I am not sure if this is true. I was hoping to get some clarification, if anyone is willing to educate me.

---

Members don't see this ad.

 

[npage148]

Your assumption is true. People want specific brands for two reasons and only two reasons.
1) they're crazy
2) some generics have higher street value

 

[HouTX]

I wouldn't make a blanket statement like the one above. I have numerous patients complained about our new valacyclovir generic. they are getting outbreaks even though they are taking it daily for prophylaxis. no problems with the old generic. I will report back with the manufacturer tomorrow when I go back in.

 

[zelman]

They aren't the same. They're the same, plus or minus a maximum variance by percentage. Also, the amount of drug in the bloodstream at a particular time after a dose doesn't need to be identical. Just similar-ish with the same area under the curve (give or take).

 

[Jibby321]

They aren't the same. They're the same, plus or minus a maximum variance by percentage. Also, the amount of drug in the bloodstream at a particular time after a dose doesn't need to be identical. Just similar-ish with the same area under the curve (give or take).

This.

Although therapeutically should there be that much if a difference? They are only allowed to vary slightly.

 

[DelPharm]

For FDA approval, generic medications have to demonstrate bioequivalence: Same molecular structure, similar pharmacokinetic profiles. I'm not sure what the allowable variation is, but there would be no discernable difference in efficacy or toxicity as long as the therapeutic window was sufficiently large. Some notable exceptions would be warfarin, phenytoin, or levothyroxine.

Also, I believe there is an allowable variation between active ingredient content listed on the packaging and actual amount in the dosage forms...something like ~10%, but I don't remember.

Either way, more likely explanation for patient perceived differences in generic v.s. brand: placebo effect. Also, what was mentioned above when it comes to the narc cabinet.

 

[pharmerjohn]

I've seen patients being allergic to certain fillers in generic, but not the fillers in brand. Not sure if this has any merit... Can someone support or dispute this?

 

[rph3664]

Some people have an intolerance to this or that excipient ingredient, and some people swear that certain generics work better for them, or have fewer side effects.

 

[Jibby321]

There is an allowable difference in efficacy. So lets say a patient got brand X the first time they filled his/her methadone and it worked well for them then if they got brand Y next time and it was on the lower end of the allowable window then the patient had less of an effect then they would want brand X always. But in general they are the same unless they are on negative formulary.

 

[npage148]

Just remember this. The criteria the FDA uses to set generic bio equivalence is the same as when the brand name manufacturer changes something in their formulation/process and needs to demonstrate its equivalency to the orginal product. Also, BCS biowaivers

 

[Rouelle]

Disregarding intolerance to an excipient, my view is that if the drug has a narrow therapeutic window and has levels regularly checked (warfarin, levothyroxine, etc) there may be some value to staying with the same manufacturer consistently. Otherwise it is unlikely to be of any consequence.

When the patient asks for their hydrocodone by name of generic manufacturer, by color, or by how much sparkles are present...then I doubt that this patient's medical condition will legitimately be affected by fulfilling their requests.

 

[zelman]

This.

Although therapeutically should there be that much if a difference? They are only allowed to vary slightly.

If they are so similar that less than 0.01% of people could experience a difference, then there will be a patient who needs a particular brand for every 10,000 people who take it. I'd expect that level of similarity to pass the FDA's evaluation AND be dissimilar enough that an issue may arise on occasion.

 

[cbrons]

Disregarding intolerance to an excipient, my view is that if the drug has a narrow therapeutic window and has levels regularly checked (warfarin, levothyroxine, etc) there may be some value to staying with the same manufacturer consistently. Otherwise it is unlikely to be of any consequence.

When the patient asks for their hydrocodone by name of generic manufacturer, by color, or by how much sparkles are present...then I doubt that this patient's medical condition will legitimately be affected by fulfilling their requests.

Thank you for your responses... it did not escape my notice that the biggest complaints on brand name at least in the clinic/office (not the pharmacy) are for things like a certain brand of dextroamphetamine (i.e. Mallickrodt vs. Barr) or benzodiazepines or various insundry opiates... these patients tend to have a high propensity to somaticize as is, but I wanted to be sure because it is a little more common than I thought it might be.

 

[radio frequency]

Thank you for your responses... it did not escape my notice that the biggest complaints on brand name at least in the clinic/office (not the pharmacy) are for things like a certain brand of dextroamphetamine (i.e. Mallickrodt vs. Barr) or benzodiazepines or various insundry opiates... these patients tend to have a high propensity to somaticize as is, but I wanted to be sure because it is a little more common than I thought it might be.

It is interesting that the patients taking medications where these things matter (like levothyroxine) rarely seem to complain, but the pain pill patients often have definite ideas about which brands work and which don't.

For what it's worth, I've been told by patients that some brands of fentanyl patches don't stick/stay on as well as others. While they could use medical tape to ensure they stay on (which would help achieve therapeutically equivalent doses, theoretically), that's likely a pain, and I can see why they might want one particular brand over another. Other than this exception, I rarely worry about these "preferences" except in the case of narrow TI drugs, such as those mentioned by Rouelle.

 

[btbucb]

According to this document, a 20% variation is allowable.

http://www.uspharmacist.com/content/s/253/c/41306/

That can be pretty significant in a drug with narrow therapeutic index.

I'm not denying that most complaints about generics are total BS.

I'd be more likely to believe someone who claims of AE differences between two different generics vs someone who complains about effectiveness of a narcotic from brand to generic.

 

[npage148]

The 90% confidence interval of the log transform data needs to be within 20%. This forces the mean of the data within a couple points of the reference dose

 

[MackandBlues]

It is interesting that the patients taking medications where these things matter (like levothyroxine) rarely seem to complain, but the pain pill patients often have definite ideas about which brands work and which don't.

For what it's worth, I've been told by patients that some brands of fentanyl patches don't stick/stay on as well as others. While they could use medical tape to ensure they stay on (which would help achieve therapeutically equivalent doses, theoretically), that's likely a pain, and I can see why they might want one particular brand over another. Other than this exception, I rarely worry about these "preferences" except in the case of narrow TI drugs, such as those mentioned by Rouelle.

I have a thyroid problem and I usually can't tell when my TSH is high or low. Levothyroxine has to be adjusted every 4-6 weeks so it's hard to remember how you felt over a month ago compared to how you are feeling now. I usually just get the brand to make things easier about juggling different generic manufacturers. I'd rather have everything remain the same than have to go in and get blood draws every 4-6 weeks to adjust my Synthroid dose.

 

[Kelp103]

I thought the FDA states an average of 3.5% difference (which they state is the difference expected in one batch of drug to another).
http://www.fda.gov/drugs/resourcesf...afely/understandinggenericdrugs/ucm167991.htm

 

[Hello2000]

A lot of it is psychosomatic. Usually the first brand or generic manufacturer given is preferred by the patient. As drugs are a daily part of a patient's life any change can upset them. I've seen a manufacturer rebrand the package of the tablet and patients coming in and saying they are vomiting and having diahorrea and want their old box back.

 

[dblock05]

Why hasn't anyone mentioned that the FDA relies on the companies to provide all the data? Do we all just trust these pharmaceutical companies 100% without questioning them?

 

[farmadiazepine]

Why hasn't anyone mentioned that the FDA relies on the companies to provide all the data? Do we all just trust these pharmaceutical companies 100% without questioning them?

This person just hit the nail on the head. This is the question that should be asked. The FDA relies on the companies to provide all the data. Look what's happened with the Ranbaxy plants in India, with Sun in India, and Dr. Reddy in India. They made up data.

 

[farmadiazepine]

They aren't the same. They're the same, plus or minus a maximum variance by percentage. Also, the amount of drug in the bloodstream at a particular time after a dose doesn't need to be identical. Just similar-ish with the same area under the curve (give or take).

So for anybody who mentions the plus or minus variance and who mentions the 90% CI with 20% plus or minus than the original, you have to remember what these numbers mean. It's statistics, and it doesn't mean a drug is 20% more or 20% less in active ingredient or in the blood stream or whatever.

This plus or minus 20% with a 90% confidence interval is THE SAME EXACT TEST THAT BRAND USE TO TEST THEIR BATCHES/LOTS AGAINST EACH OTHER. As long as the data provided by the generic company is 100% true, then a generic is exactly the same as a brand in terms of blood levels and active ingredients.

The test used to compare generics to brands is the same exact test that brands use to test their own lots against each other!

 

[rxkrafted]

If you want to check for therapeutic equivalence, you can check out the Orange Book

 

[Dred Pirate]

One interesting study I read is that individual lots of brand name coumadin do not vary any more than the difference between brand and generic- so that vast majority of people complaining about generic are BS - although I will admit there are a few rare cases it is significant

 

[Hello2000]

Why hasn't anyone mentioned that the FDA relies on the companies to provide all the data? Do we all just trust these pharmaceutical companies 100% without questioning them?

The FDA does inspections of each manufacturing facility be it in the US, India etc and presumably takes random samples from the line.

Doctors are advised not to switch brands of anti-convulsive medicarions.

 

[type b pharmD]

The FDA does inspections of each manufacturing facility be it in the US, India etc and presumably takes random samples from the line.

Doctors are advised not to switch brands of anti-convulsive medicarions.

Doesnt AACE also recommend against changing brands of thyroxine? May be wrong on this

 

[BeLikeBueller]

Doesnt AACE also recommend against changing brands of thyroxine? May be wrong on this

AACE, American thyroid association and some other organization I forget

 

[sakigt]

This person just hit the nail on the head. This is the question that should be asked. The FDA relies on the companies to provide all the data. Look what's happened with the Ranbaxy plants in India, with Sun in India, and Dr. Reddy in India. They made up data.

This post cannot be missed. Patients are crazy, Ill give you that. But you cant be 100% confident in the generics (or for anything for that matter) for the reasons above.

 

[KidPharmD]

This post cannot be missed. Patients are crazy, Ill give you that. But you cant be 100% confident in the generics (or for anything for that matter) for the reasons above.

Can you be 100% confident in the data provided in the brand name?
Does anyone remember when Pfizer decided to changed the formulation of the brand name Kapseals? They were brand name and they were supposed to be identical to the previous version. However, we had patients who had to switch to the Mylan generic because they were having reduced seizure control on the new brand name!

Brand name only matters when consistency matters. I would argue that you will get no less consistency from sticking with the same generic manufacturer. This is simply more difficult than getting a "Brand name only" script.

A poster above made a certain point. The same amount of variation allowed between generic and brand name, is also allowed between different lots of the brand name.

If you are a pharmacists that preaches that generics are somehow therapeutically inferior, you better have some good EVIDENCE to back that up.

 

[KidPharmD]

AACE, American thyroid association and some other organization I forget

AACE, ATA, and TES all recommending sticking with one brand of thyroid medication. However they do not claim that brand is better than generic, or that you shouldn't use generic, only that you should stick with one.

 

[BidingMyTime]

Everyone is right in this thread. I agree 1) placebo effect is strong & the reason many people think brand works better than generics 2) higher street value for brands and some specific generics 3) companies could lie, that has been known to happen--probably not that much, 4) there is always going to be the in 1 in 10,000 (or whatever) rare person who really does do better on one over another.

Realistically, few pharmacies can afford to carry different types of generics based on pt preference. I have ordered specific generics for pt's based on their request, but this isn't always possible (or financially feasible.) Brands can always be ordered, although not all insurances will pay for brands without a PA.