Hello, I was taking generic Wellbutrin XL made by Teva 150mg 1x/daily for one month and it seemed to be working okay, not perfect but okay. I decided to try out the expensive Wellubtrin XL 150 brand name and took my first pill today and really didnt expect any side effects but it's giving me some nice headaches on day one. It really amazes me how just switching from generic to brand name is enough of a change to cause the start up side effects all over again. I'm sure in a day or two the headaches will be gone but it's so strange since technically the medication is identical right?

I feel like I'm expirmenting too much and maybe should have just stuck with the generic however I will try this for one month and see if I feel any better than I did on the generic. I should stop searching for the perfect form of WB but have read so much that the brand name is better?? Has anyone else out there made this switch and if so and comments good or bad?

I think it's important for everyone to realize that when you make any switch, even if it's the same dosage but different manufacturers, you will probably experience an adjustment period with side effects. This can happen whether you switch from name brand to generic, or vice versa. Thankfully, the transition from one brand to another is usually nowhere near the severity of first starting the drug.

Generic formulas are hoped to come as close to the original as possible, but there is some leeway allowed as far as rate of release and overall amount of the drug. There are also different "inert" ingredients involved, like what goes into the pill shell.

I made the switch from name brand Wellbutrin XL 300 to Teva's generic formula. I felt that it released faster, and I got much more of a boost early on in the day, but over time it evened out. In less than a week, I couldn't tell it apart from name brand.

Thanks for the info and what you say makes sense. Even on day two I feel better without any headaches so I'll see how I do on this for a month. If I don't notice much difference from the generic I'll switch back on the
Teva generic and cut the cost down a bit. The name brand is very expensive and should I ever up my dose to 300 mg's I suspect it gets even more expensive...

I work in the field of post-Phase 4 clinical trials which test generic medicines for bioequivalence. We have to adhere to world wide standards of what is known as 'Good Clinical Practice'.

IF the generic was tested against the original first-registered brand, the aim is for as little difference as possible, although there is still variance from person to person (just as there would be with the originator product.) Bioequivalence is considered to be established (meaning a generic may be registered as such) if the rate and extent of release is within 80 - 120% variance from the originator product; these percentages vary from country to country, as well as on the innate variability of each drug (some are just known to be highly variable.)

Further variance comes from a generic being tested against another generic (if the first drug was at 80% absorption, and the second drug is 80% of that one, they can get further and further 'out'; the implications in this case are mainly in dosage amount, so this can be corrected for.) Each generic should ideally be tested against the first such product registered in that country, (which may well be a generic and there's no problem with that), although that doesn't always happen (depends on how jacked the medicines control regulatory body is, in that country). This just means that in one country you may need 150mg and in another, 300mg. You can't always compare against countries, not even within the Brand name, as manufacturing conditions may vary.

Then, as Burgy says, variation can also come from inert ingredients (more especially the different shells or formulations used to make the product release faster or slower, like the SR and XL versions), as well as each individual person's uptake of the drug. Each person's uptake varies, depending on their metabolism and genetic make-up, and there is no such thing as an average person. When we do trials, we have to have enough enough subjects to have meaningful averages and to make a statistical analysis valid.

Also, any drug you take, may alter the blood levels of the other drugs you're taking. Currently the Epilim I'm taking approximately doubles my blood levels of Lamitor (a generic of Lamital). I've also just been switched from the SR to the XL version of WB, so who knows what that will do? You have to trust your pdoc to know what s/he's doing, as s/he has the experience.

Add to the variability mix, unscrupulous and shady companies who fudge results or just make up entire trials which were never conducted. That, fortunately, is easy enough to check - if a company is reputable, they are reputable.

Then add factories that do not adhere to 'Good Manufacturing Practice' (ie temperatures not being kept constant, cheap and faulty packaging etc). Or factories that "unfortunately" burn down just before an inspection (that is a real case!)

I know this is a barrage of information. But there are lots of factors and it's not a simple equation. All of these factors are compelling reasons to follow your doctor's instructions, and preferably to see a psychiatrist, if your needs are complex and the second or third drug you've tried hasn't worked too well. Stick with what YOUR doctor says, regardless of whether it is different from what you hear of another person's treatment.

This post has been edited by moonlightress: Nov 11 2008, 10:31 AM