Generics versus Brands: Are They Really the Same?

[David Baxter PhD]

Generics versus Brands: Are They Really the Same?
By DaveMSW
September 21, 2009

This is a topic that gets scant attention leaving the consuming public largely in the dark. Even though I work in the field, I've not hear this information except from my own reading. Fortunately, SSRIs are not as susceptible to problems crossing from brands to generics or between generics. But buproprion in other forms may not be as good as Wellbutrin.

Antidepressant and antipsychotic drugs have become blockbusters for the firms that developed them, making them hot markets for generic competition. Moreover, the effectiveness of these drugs is measured in the same way as anticonvulsants -- either they work or they don't.

Consequently, psychiatry is another specialty that has had to think about how to handle the variability in potency among generics.

Michael Thase, MD, of the University of Pennsylvania in Philadelphia, said that when problems do arise, it's usually when patients switch between different generic versions of a drug.

"There are multiple generics," Thase said, noting that broad bioavailability confidence intervals allow for substantial variation between different generics. "If the pharmacy changes generics frequently, which often they do because it's a highly competitive business ... you might have some series of 40% fluctuations," he said. "Every few months there might be such a large fluctuation."

But for antidepressants, clinical problems resulting from these fluctuations are not that common, he said. The dose-response relationships with SSRIs are not rigid, and, therefore, patients generally don't see big changes in drug effects, he said. "You might have an increase in side effects with the change, or you might feel you've lost a bit of the therapeutic effect."

But some non-SSRI antidepressants aren't so forgiving, said Jeffrey Lieberman, MD, a psychiatrist at Columbia University in New York City. He mentioned the tricyclic drug nortriptyline and bupropion (Wellbutrin) as more susceptible than most antidepressants to dosage variations. In the case of bupropion, he said, seizure risk is relatively sensitive to dosage.

Thase acknowledged that cases do occur when patients suffer serious problems following switches to or between generics. But he said those cases tend to have an outsized influence on perceptions. "You don't hear about all the times [problems] don't happen," he pointed out. "We may think it's a bigger problem than it is."

Lieberman said the common antipsychotics generally posed few problems with generics. He said anecdotal reports of problems tended to focus on clozapine. "[It] seems to be a particular compound that suffers from this kind of experience," Lieberman said. But he cautioned that these reports may result from "the kind of selective memory Michael [Thase] was talking about."

Lieberman noted that it was hard to pin down the potential for problems because -- as is the case with the antiepileptics -- systematic, controlled trials to compare different generic formulations and the branded original are generally lacking.

More information: Medical News: Generics versus Brands: How It Plays Out in Practice - in Product Alert, Prescriptions from MedPage Today

 

[NicNak]

Is this article also talking about the third generation generics too? Specifically SSRI's

I know it is selective per person, we are all different. I was on fluoxetine (prozac generic) , an SSRI, by one generic supplier. The drug store had then switched to a third generation supplier and I was told the molectural structure was identical, so I didn't even pay much mind to the switch.

Then about a month later, I went to my doctor about feeling like I had crashed. It wasn't until then while we were talking that I remembered about the third generation supplier. From tha time on, I have always stayed with name brands, to be safe.

I have to add, I have always had sensitivites to medications.

 

[Retired]

I was told the molecular structure was identical

The molecular structure is always the same, that's why it qualifies as a substitute under generic definitions. The differences are in the source of raw materials, the inert ingredients, the manufacturing processes and the tolerances of quality control.

Pharmacists are not always your best advocates in deciding which or whether generics are right for you, because some pharmacists are interested in selling the generic that costs them the least, in order to make the largest profit.

If the cost of prescriptions is an issue, then the best advice would be to find a generic that provides satisfactory effectiveness for you along with the best tolerability (least adverse effects) and insist on getting that same manufacturer's product.

If your pharmacist can't get it, go to another pharmacy and insist on the same manufacturer.

If the cost of your medication is not an issue, and you want 100% assurance of consistent performance, ask your doctor to prescribe by brand, and to write "No Substitution" on your prescription. In jurisdictions where pharmacists are allowed to substitute despite the doctor's instructions, make it clear to the pharmacist that your want the brand name, and if you don't get it, you'll take your business elsewhere.

A good pharmacist will comply with your request without trying to persuade you to accept a substitute. Occasionally, a manufacturer will be back ordered on a given product temporarily due to unexpected problems, and a temporary substitute may be required, but you should be returned to your product of choice when the situation returns to normal.

Advocating on your own behalf as an informed consumer is as important in the pharmacy as it is in other purchases, if not more important because your health care, your wellbeing and quality of life are at stake.

addendum: when your pharmacist fills your prescription, ask that the real expiry date from the manufacturer's original container be indicated on your label. Some pharmacies (especially the large chains) like to place their own arbitrary expiry date, which is sooner than the manufacturer's date. The reason? If you don't use up all your prescription, by their date, forces you to go back and renew your prescription and discard what you have. This occurs mostly with PRN or use as needed prescriptions.

 

[NicNak]

Thanks Steve, that is fantastic information.

I do that ever since the problem with the third generation generic. I get my doctors to write "no subs" on my prescription. My current pharmacy is really good with me in all ways. They always make sure they have the brand name of Effexor XR on hand.

I always try to stay on the same medication. If I start on a brand name, I stay on it. If I was first given a generic, I stay on the one first got. I am way more careful now after that incident previously.

Thanks Steve for your input, great info.

 

[Retired]

brand name of Effexor XR on hand

Good for you! At present there are three manufaturers of generic venlafaxine extended release in Canada competing with Wyeth Effexor XR.

 

[NicNak]

Good for you! At present there are three manufaturers of generic venlafaxine extended release in Canada competing with Wyeth Effexor XR.

Wow! That is a lot, but I guess once the patent expires on the origional brand name, it is an open market for manufacturing the generics.

I often wonder too, although the pharm companys do not seem to be hurting

Isn't it the origional makers the ones who finance all the research that goes into making new prescriptions?

I guess that could be why they are so expensive to start, as they get back as much as they can before the patent runs out?

 

[Retired]

There is no doubt that pharmaceutical companies are profit driven, and at times their corporate behaviour leaves much to be desired.

That being said, it is the incentive to develop new and effective medications that supports the research and development of new drugs. Millions are invested in research, which sometimes yields nothing.

When a successful product is developed, their shareholders expect their investments to pay off.

Advocates of the pharmaceutical industry will claim that in non capitalist countries pharmaceutical development does not make advancements.

The corollary to that claim is that in capitalist countries, drugs needed for conditions that afflict small percentages of the population are rarely if ever developed.

Some advocates for affordable medications will claim that multinational drug manufacturers will charge what the market will bear from one country of operation to another.

Advocates for the industry will counter by saying the industry subsidizes less affluent societies so everyone can benefit from their medication.

Perhaps there is a bit of truth in all claims, but in my opinion, even though some generic manufacturers may be producing consistent quality, for proven consistency of quality, the brand manufacturer's product can always be counted on.

That isn't to say some of the larger generic makers such as Apo and Novo may not be producing to the high standards of the brand name manufacturers, or that all generics are sub standard as some of the brand name companies produce their own generics, but I would want to be selective in any generic I would be required to purchase.

 

[arnett]

I know in my case that there is one generic version of Wellbutrin that simply does not work for me and I have to be sure the generic I get is the "right" one.