possible drug interaction report

April 6, 2012 4:28 PM

How do I report a suspected drug interaction? To my doctor? The FDA? Long deduction inside....

About six years ago I was put on Drospirenone. A year later I was put on Topiramate to treat headaches. Immediately I began losing weight - my stomach was upset and I didn't want to eat a thing. It was nice in the beginning to shed a few extra pounds, but I soon barely had enough energy to get out of bed. The doctor said that was sometimes a side effect of Topiramate and switched me to Propranolol. Problem solved!

Then, about four years ago, I moved to Nebraska where Drospirenone was $60/month. So I took myself off it :-/ I moved to a different state shortly after, but did not bother going back onto Drospirenone.

Last year I started allergy shots - which negatively interact with Propranolol. So my new Dr. suggested Topiramate again. I hesitated, remembering how awful the side effects had been....but it was either that, the headaches, or continue being allergic to my dogs so I went back onto Topiramate (besides, I wanted to take off some of my Nebraska weight....) and....nothing. Not a single bit of stomach upset. Not a tiny bit of appetite suppression. Not a pound shed! Hooray! ...ish, I suppose. :-)

Anyway, so a while later, another doctor wanted to put me on Claravis...which requires you to be on Drospirenone (or similar) a month before beginning treatment, so I go back on Drospirenone and....SAME symptoms as five years ago. *Massive* appetite loss and stomach upset, all day, every day, can barely get out of bed.

Now, the Drospirone isn't actually required for Claravis to work effectively (it's only required because someone at the FDA thinks all women are stupid and irresponsible) and I still need to take Topiramate for my headaches, and can't switch because I'm still doing allergy treatments. So I stop taking the Drospirone and bam, symptoms are gone again.

So. Bottom line, I think there's a drug interaction between Drospirenone and Topiramate - because when I take each alone, I'm fine. The only current interactions I can find it that Topiramate reduces the effectiveness of Drospirenone, but nothing about these weight loss and severe stomach upset side effects. I know Topiramate is sometimes used off-label for weight loss, and now I'm wondering if it doesn't work that way unless the woman's on this other drug. (Out of curiosity, has anyone experienced anything similar?)

So to make a long story longer, how would I actually let someone know about this? I was planning to talk to both my doctors (the one that prescribed Topiramate and the other that prescribed Drospirenone) but should I contact the FDA? I saw there was a form on their site, but it seemed to be only for "serious" side effects, and the ticky-boxes were really for "death" or "hospitalization" .....considering I did not let it get that bad, I don't have that information!

posted by Lt. Bunny Wigglesworth to Health & Fitness (16 answers total)

Best answer: Given your information about the FDA's form for reporting drug interactions, it seems logical that the only thing you can do in this instance is tell your doctors. I imagine they have the appropriate means of communication with the drug manufacturers and/or the FDA, should they notice this interaction to be a pattern among their patients.
posted by Specklet at 4:43 PM on April 6, 2012

Your pharmacist is also almost always an awesome resource for stuff like this! They may have heard similar stories from other customers, which is great (in a bad way i guess) because then you're not an isolated incident, and they will likely know the best way to make any necessary reports.
posted by elizardbits at 4:45 PM on April 6, 2012 [1 favorite]

This is kind of a weird question, my understanding is that hormonal birth control is already contraindicated for anyone taking Topiramate.

I would make sure you tell all of your doctors as well as your pharmacist. This is exactly what pharmacists are theoretically for and, from my experience, they love putting their educations to work.
posted by Blasdelb at 4:49 PM on April 6, 2012

I am not sure the situation is entirely analogous, but when I had an allergic reaction to a prescribed medication, my doctor reported it to the drug company ("Wow, only 3% of the people who take this drug have allergic reactions to it...mind if I get pictures of those [*enormous*] hives to send to the company?"), so my thought is that there is an in-place mechanism for your doctor(s) to report these things. My doctor may just be a nerd (there is some evidence)...your nerdish-doctors-mileage may vary.

Telling the pharmacist about it is also not a bad idea.
posted by faineant at 4:59 PM on April 6, 2012

Response by poster: Blasdelb - the contraindication is for the decreased effectiveness of the birth control, not for actual physical side events. Although I was not told of Topiramate decreased effectiveness of Dropirenone, I was put on Drospirenone for non-contraceptive reasons (just hormonal regulation), and that could be why my doctor thought it would be all right to put me on both. It may also be why this interaction hasn't been recorded, because people are rarely put on both.

Though, on a similar note, the use with Claravis was supposed to be for contraception....part of me thinks I should tell/remind my doctor about the decreased effectiveness when patients are taking topiramate (since I was not informed)....but the other part of me doesn't want to make it any ridiculously (compared to men) harder for women to get this drug than it already is.
posted by Lt. Bunny Wigglesworth at 5:02 PM on April 6, 2012

Definitely tell your doctor. After evaluating you, if they are nerdy enough, they may want to write a case report about your experience.
posted by en forme de poire at 5:02 PM on April 6, 2012

Response by poster: Faineant - I don't think it's entirely analogous - anyone can be allergic to a drug, and if I were simply allergic to one or the other, I'd simply chalk it up as a bad reaction and not feel the need to take it any further. But it's when both are taken together that the reaction comes about, which makes it think that it's *probably* not me (although I suppose there could still be a slight chance my body's just breaking them down weirdly and it's these strange byproducts that are interacting or something....)

But my doctor's pretty good! I'm glad everyone is suggesting this - I was feeling a bit weird being all, "oooh, look at me, doctor, I'm doing your job!" XD
posted by Lt. Bunny Wigglesworth at 5:06 PM on April 6, 2012

You're not doing their job, you're just reporting symptoms and the cirumstances that you've noticed around them. If you'd been seeing one doctor all along, and he had been prescribing you all the stuff you'd been on, then it might be reasonable that he'd notice this pattern. But seeing two different doctors and getting prescriptions from both of them means neither of them has enough information to realise that this even happened.
posted by jacalata at 5:18 PM on April 6, 2012 [1 favorite]

Yeah, no...I didn't mean your body's reaction to the combination of drugs is analogous to an allergic reaction, I meant that the situation I had with an adverse reaction and my doctor's comment, makes me think that your doctor(s) may (probably?) already have a mechanism for reporting side effects/adverse reactions to drugs.

In any case, good luck!
posted by faineant at 5:28 PM on April 6, 2012

Tops max is known to not have the weight loss side effects if you go off of it and then back on. So, factor that into your analysis somewhere
posted by atomicstone at 5:42 PM on April 6, 2012

FDA medwath form. Your doctor and your insurance company to see if a daw override is needed to know cover brand med without cost skyrocketing for your copayment
posted by Bun Surnt at 6:05 PM on April 6, 2012

** FDA medwatch form.
posted by Bun Surnt at 6:05 PM on April 6, 2012

Response by poster: Jacalata - I do always check in with my PCP for everything - when the second doctor recommended Drospirenone (and gave me a sample pack), I talked it over with my PCP (who had prescribed the topiramate) before starting treatment. She also thought it would help with the resurfacing issues I was having (that I'd started taking it for six years ago). So my PCP was aware I was on both, as was my pharmacy, which has been very good about notifying me about drug interactions.


Atomicstone - Interesting, because I DID experience the weight loss again...but *only* in conjunction with Drospirenone (because I was so sick to my stomach I couldn't eat....which is *exactly* why I experienced weight loss the first time)
posted by Lt. Bunny Wigglesworth at 6:07 PM on April 6, 2012

You can email the manufacturers of either or both drugs. They are required by the FDA to track adverse events. I used to manage this kind of reporting as part of my job for a drug manufacturer.
posted by kamikazegopher at 8:18 PM on April 6, 2012

Work in Big Pharma:

Your doc definitely has the means to tell drugs companies about suspected interactions with their drugs. They(Pharma) take this process very seriously
posted by Patbon at 6:36 AM on April 7, 2012

I have worked in drug safety for several years. This is what I do all day long. You have several avenues to report this. You can use the FDA's MedWatch form even if you did not experience a serious adverse event ("serious" is defined by things like hospitalization, death, life-threatening, etc., as you mentioned). Just don't check any of the boxes if none apply. You can also report this to your doctor(s) or a pharmacist, but there is no guarantee that they will then report it to the pharmaceutical companies in question and/or the FDA on your behalf. It is voluntary for physicians and pharmacists as well as it is for you. Your best bet, in my opinion, is to call the number of each of the pharmaceutical companies that make the drugs you've been taking. The numbers to call will be found at the bottom of the package inserts (your pharmacist can give you these if you don't normally get them). I would look up the numbers for you, but I am not sure whether you're taking generics or not. In any case, if you report directly to the companies that make the drugs, they are obligated to report this to the FDA, as well as any other regulatory agencies in which the drugs are marketed. It may take a year or more, depending on whether the event is assessed as serious by the companies' physicians, whether it is expected (i.e. present in the package insert of one or both of the drugs), and a few other factors. However, all companies are obligated to submit periodic reports for all of their drugs, and these periodic reports contain all the adverse events that have been received, even if they are not "serious." So if you consider this interaction to be something the regulatory authorities need to know about, you should report it directly to the drug companies since they are the only ones who are actually required to do anything with the information. Be prepared with your physician's contact information if you are okay with providing it, and let your doctor know you've reported it and that you would appreciate it if they would respond to the drug companies' requests for further information. After that, you've done all you can do as a consumer. But yes, drug companies take this sort of thing very seriously, because they are required to by law.
posted by feathermeat at 6:14 PM on April 7, 2012 [2 favorites]