Warning to those taking generic topiramate

If you are taking topiramate, just a warning. Make sure you get your medication from the same generic manufacturer every time you fill your prescription.

I have been on topiramate for about 6 months. I recently moved, and there are no Rite-Aids in my new area so I changed to CVS. Well, the CVS had a different generic supplier of topiramate. I had been getting one made by Camber, but this one was made by Glenmark Generics.

This very quickly became a big problem. At first I thought I was just feeling a placebo effect because I knew the pills were different. But within about 10 days it was obvious to me that there was a real problem going on. I was having all kinds of head pressure and light sensitivity issues, though thankfully no MAV reoccurrance. It felt very similar to when I was initially ramping up back when I was about at 75mg. I talked with a pharmacist and he said that the generics can differ in dosage from the brand name as much as 20%. So if the Camber is high by 20% and the Glenmark is low by 20%, the difference between the two could be as much as 40%!!! So switching from one to the other could be effectively like going from 120mg to 80mg overnight. I don’t think it was that dramatic–it felt more like I went from 100mg to about 80mg, but it still felt like something was wrong.

Calling around to several pharmacies in the area I was able to find one that carried the Camber generic. It cost me a fortune to chuck my half-used Glenmark pills and replace them with Camber pills out of pocket (insurance won’t cover them because they say I can’t get a new prescription for at least another week still) but at least I’m back on the medication that was helping me. I’m a bit bummed that something as small as changing the generic brand of topiramate set me off that much. Considering I was practically 100% I thought maybe I could even come off of the topiramate entirely, but obviously that isn’t the case at all, which is discouraging. But the main point I wanted to get out there to others is, make sure you are consistent with what generic form of topiramate you use, as going from one brand to another can mess you up. And don’t assume that just because you use one pharmacy all the time that they will always have the same generic brand. Some pharmacies change the kind that they use randomly. So check with your pharmacist and find out how they go about ordering their generics so that you know exactly what you will be getting before hand.

Do you think this applies to all meds? I noticed a difference with the amitriptyline made by different manufacturers but thought I was imagining it

Oh no, I have a different brand of nori for my latest prescription, hope it’s ok. It is quite hard to know what they will give you. Donna - have you upped the ami to 30mg yet? Have you decided what to do about Dr S? x

Hi Jem
Im on 30mg now I am hopefully going to see him but my Dad has to take the time off so I wont know till a few weeks when I will be going but I think Im improving fingers crossed X I noticed one brand works better for me so Im defo asking for it from now on I knew I noticed a difference but thought It was me just thinking it X what are you doing about meds in the meantime jemma? X

I still on 25mg nori at the moment. I am due to see Dr S next weekend I hope so am waiting til then to see what he says. I don’t really want to take any more of the metoprolol or the gabapentin until I see him as they both made me feel worse x

So weird what did Trish say about the gaba? Does she feel thats improved her or the pitz? Ive really been researching this migraine thing this past couple of weeks and its believe low serotonin is the cause of it and more prevalent in people who have suffered depression in the past.
I had really bad PND after my first son was born I do think thats probably a big cause for me my Dad also has bipolar disorder so could be a genetic element with low serotonin with me. What do you think about it?

Trish said Gabapentin made her feel bad for a good few weeks before it started helping. I think she was on Pizo for a year or so before she saw Dr S and got the Gabapentin about 2 months ago. I don’t think the Pizo can have helped her a lot from what she said about how she was feeling before she saw Dr S. I think she started on a lower dose of Gabapentin and has just seen Dr S again and is increasing it.

I read too that low serotonin can be linked to migraines. I think it’s possible in my case that is the cause although I am sure there are others causes too and that is why some people react differently to different meds. I think I may be prone to depression, I definitely feel like I could be even though I never got diagnosed with it or asked any doctors about it. Certainly with this condition it has made me very depressed. I also believe hayfever is a trigger for me and Becks told me that she heard that high histamine levels in the brain can make MAV worse.

I would be happier targeting the serotonin first and seeing if it helped as throwing too many meds into the mix at once is confusing x

I do not know if this is as much of a problem across all medications. I know that small dosage changes in topiramate affect me FAR more than they do in other medications. So it may be a much bigger problem with topiramate than with other medications.

I read some forums online about people specifically having trouble with topiramate generics and migraine who had trouble when switching generic forms, and the CVS pharmacist said he definitely recommended people on generic topiramate to try and stay with the same manufacturer if at all possible. If you are on a different medication I wouldn’t work yourself all up over it as we have enough to worry about all ready. But I definitely had a problem switching between the Camber and Glenmark topiramate generics so I wanted to share my experience. My MAV symptoms did not come back, but I had increased migraine symptoms and light sensitivity, and I could definitely tell that my medication dosage had been changed in some way. Normally I am very med tolerant, but changes in topiramate dosage are pretty noticable.

GREAT info…thanks for sharing!

Also note, if you absolutely cannot get the same manufacturer, you can probably adjust the dosage of the new manufacturer to get back to where you were. In my case, going up to 125mg of the Glenmark generic probably would have done the trick. But given how well I was doing on the Camber generic, I didn’t really want to go thorugh the process of figuring out what dosage of the Glenmark I needed to be at to be OK.


It’s so frustrating that first we have to go through hell by trialling all sorts of medicines until one works. Then once u stabilize and believe that u can start to come off the meds, u try to come off and your symptoms come back. I hate being on meds but I have no choice. I always pray that one day I can come off them

I’m very surprised the pharmacist told you there was a possible difference of 20%. That is definitely not the case in Australia. The TGA would kill the manufacturer if they screwed up like that.

One thing that has caused me to freak out when I swapped meds was the change in packing agents or excipients. I went from the main brand of Cipramil years ago to another brand called Telohexal. Disaster. Anxiety came back like a freight train within 2 days. As soon as I switched back, BOOM, back to normal.

I know that my ex was told that he must always get the same brand of Carbamazepine for epilepsy and this was extremely important as it can change the doseages, and ultimately lead to a seizure due to poor seizure control.

Obviously if the drug concerned is controlling something like epilepsy, the consequence of the doseage adjustment becomes more serious.

I don’t know whether this problem is seen more often in anti convulsants, but it was definately the same advice for Carbamazepine.

Yes, I should have pointed out that this was a USA issue. This 20% problem is an FDA rule. So those of you outside of the US may have tighter regulations on your medications and may not have this issue.

You have to understand, here in the US, we have half of our government devoted to the mantra that any and all regulations on business are bad and must be removed in the name of maximizing profits. So who cares if medications vary by 20% of the dosage they are supposed to be? They are probably a lot cheaper to make that way so the CEO of the company can get way richer. And the only thing important in life is making rich people richer.

That’s interesting Jamie, god knows what the position is here in the UK. I did wonder though whether the neurologists have any incentive for pushing one particular med over another, maybe they get financial or other benefits if they prescribe the big drug company’s meds above others, I don’t know if that is illegal?
For instance, I noticed some consultants don’t seem to be as keen to prescribe nortriptyline or amitriptyline and I wondered if that is because these are old medications and the incentives are not there like they would be with newer meds. Or if they really do just prescribe solely based on their opinion of the efficacy of the med for that particular patient…

Jem- I thought that docs, (particularly those on the NHS) just issue under the rule of ‘whatever is cheapest’…

When I went to my GP to say Sumatriptan wasnt working as an abortive, she prescribed me Zomig, and a warning actually pinged up on her screen telling her this drug was costing the NHS a lot of money and told the doc to question whether the patient really needed it…!!

Really!! Yes that doesn’t surprise me at all actually. I guess it’s all about cost one way or another. I think nori and ami are quite cheap drugs but some of the others like topamax and flunarizine etc i bet are more costly x

The FDA is really OK with being off by 20%?? That’s insane!! How is that OK???

I’m on generic topiramate, and I’ve had to go up from 100mg to get better symptom control, but I wonder how much my dose really is since I’m on the generic instead of “real” Topamax…


Well, looking into it, it is not quite that simple. Here is an article to try and explain it:


It isn’t quite that the FDA allows the dosage to be off by 20%. But they allow the bioavailability parameters of the medication to be off by 20%. This can lead to dosage differences. How much of a difference? Hard to know exactly. But it is clear there is SOME difference. Probably not as much as 20%, but probably enough that what I was noticing with the topirimate wasn’t my imagination.

Im having this same issue!!! My topiramate was through a different pharmaceutical company and it was the ZD 14 100mg and i was on it for yrs all was great with this one. I move out of state and i get refill and the pills are yellow here and say 100 and G on back im having serious anxiety issues, weight gain, angry for no reason, my doc is just telling me i just need therapy and anxiety meds wth!! Fix my pills!