Tuesday, September 30, 2008

Gabitril Goes Down

ResearchBlogging.orgGabitril (tiagabine) is an antiseizure medication from Cephalon, which just forked out a cool $425 million to settle charges that it marketed several drugs for unapproved conditions, including Provigil and Gabitril. Government investigators claimed that Gabitril was marketed as a treatment for anxiety, which is too bad considering that it struck out in three clinical trials against a placebo. Each study found no evidence that Gabitril was better than a sugar pill.

Gabitril was also allegedly marketed as a treatment for pain. I was unable to locate a single controlled study examining the efficacy of Gabitril for pain, though there were a small number of uncontrolled (i.e., not very useful) studies suggesting that maybe Gabitril could be used to treat pain. Regarding sleep, the placebo-controlled trials I located did not suggest that the drug was particularly effective (1, 2). So we're looking at a drug with essentially no controlled evidence of efficacy being pushed for pain, sleep, and anxiety. Well-done, Cephalon.

Some of the supporting evidence about the off-label marketing cases came from a sales rep who wore a wire to collect evidence on the company's marketing practices. Apparently a total of four company whistleblowers were involved. Shades of Peter Rost?

Read more about the case at the Philadelphia Inquirer.

PS. Cephalon published the negative anxiety Gabitril trials in June 2008. As is well-established, companies often fail to publish negative data about their products, so why is Cephalon being so open? A skeptic might note that with the legal case againt Cephalon gaining steam, it would look even worse if Cephalon was sitting on negative data. So perhaps knowing that bad publicity was coming due to the lawsuit led Cephalon to allow the negative anxiety results to be published, as they could state "Look at how open and honest we are." I'm just saying that it's a possibility.

Reference for anxiety trials:
Mark H. Pollack, Jane Tiller, Fang Xie, Madhukar H. Trivedi (2008). Tiagabine in Adult Patients With Generalized Anxiety Disorder Journal of Clinical Psychopharmacology, 28 (3), 308-316 DOI: 10.1097/JCP.0b013e318172b45f

Update: Also read a related post at Health Care Renewal. It mainly discusses Cephalon's opiate-laced "perc-o-pops" (Actiq) approved to treat cancer pain, but marketed in a much broader manner.

Follow-up mini-rant: Let's not excuse the physicians who jumped on board. Docs need to do a much better job of checking the evidence base, though when some of the evidence base consists of publishing the same data repeatedly and when negative trials are often not published, what kind of "evidence base" are we really talking about?


Anonymous said...

I can tell you what Gabitril can cause -- anaphylaxis! As a general internist I admitted 2 pts within a 6 month period when a local psychiatrist started putting EVERYONE on Gabitril.

First, do no harm.

Anonymous said...

I have been taking this drug for nearly 3 years for anxiety and sleep. Yes, a little confusion initially but after a while the side effects mellowed. I have also tried a number of other drugs which did little or nothing and the side effects were so dastardly the drug was not worth the benefit. THIS MEDICATION HAS BEEN A GODSEND FOR ME. People with severe anxiety are often drug resistant...making efficacy very subjective!

Anonymous said...

I had a sever racing thought rection to Neurontin, so they tried Gabitril for anxiety. It took a full year for all anxiety to leave and I was never told of the pain relief part, and I wondered why my pain had gone down,only then did I read about that.
There seems to be 3 Gaba sisters, Lyrica, Gabitril and Neurontin and if you can tolerate any of them, the long term effect are amazing on anxiety for Fibromyalgia.

Anonymous said...

Gabitril sure puts me to sleep in a hurry. Dont believe everything you read. This medicine does work for anxiety and sleeplessness. At least for me.

Anonymous said...

Oh my God. That post above where it say Neurontin gave racing thoughts and after a year on Gabitril all anxiety was gone and is a Godsend for Fibromyalgia.
I couldn't have written that, but that is exactly what happened to me! Exactly. As each month passed, my anxiety lowered and lowered until it was gone. I think they need to test it on Fibro patients, since it works great for our community.

Anonymous said...

I'm sure noone will read this, since this post is very old. But I can verify that this stuff works where no other drug has. It has allowed me to sleep deeply and enter REM sleep, which I hadn't done in almost a year. It has relieved a considerable amount of pain, better than anything else I tried. And it does relive a certain amount of anxiety to boot. So everything you said it didn't work for? It did for me. And trust me, I've tried a LOT of medications.