Quote:
Originally Posted by mrsD
It has to do with cancer of the pancreas risk. And that parent company did not provide NEW data showing increased absorption was safe.
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That's what I gathered. The original study (and risk) applied to
gabapentin, which has not been approved for pain either, yet is still a first-line treatment for a number of neuropathic pain conditions which it has not been approved for.
Regarding the cancer risk, the paper also goes on to add:
Quote:
....Gabapentin was approved .... in part because of the serious nature of the disease to be treated (epilepsy). Moreover, particular factors provided reassurance regarding the non-clinical findings: carcinoma were observed in only one sex, they were not locally invasive, and they neither metastasized nor shortened survival.
....
One of the difficulties in extrapolating this risk to humans is the rarity of this particular tumor type: the vast majority of human pancreatic cancers are ductal in origin; acinar tumors are rare. Although the difference in tumor type was appreciated by the review team, there was inadequate information to establish that these tumors were not clinically relevant. ....
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From what I've gleaned from this article and others, it seems to boil down to
gabapentin and
gabapentin enacarbil having virtually the same risks.
Quote:
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It is only a sustained release form of gabapentin, and therefore not new, exactly.
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What I read is that
gabapentin enacarbil is a form of
gabapentin with
increased bioavailability with both immediate
and extended (sustained) release formulations.
http://jcp.sagepub.com/content/48/12/1378
Horizant® is an extended (sustained) release form of
gabapentin enacarbil.
http://www.medilexicon.com/drugs/horizant.php
I wasn't wondering so much about immediate vs. sustained release, but about the increased bioavailability (in part concerning people with absorption issues - e.g. IBD). If,
for example, someone with PN who was taking 1800 mg. of
gabapentin/day could get the same benefit from only 300 mg. of
gabapentin enacarbil, might the associated risks, side effects, tolerance, etc. be reduced as well? (Proportionally reduced risk might also sway the argument for FDA approval.) Might the more bioavailable form work for someone whom
gabapentin did not? Also, since the analgesic benefits of
gabapentin "top out" at a certain level (beyond which higher doses don't yield appreciable benefit), might that limitation be modified to the patient's advantage? (I'm lacking the words to say that properly at the moment...
)
The questions are rhetorical at this time, but yes, I'd be interested in any feedback from people who'd tried it. The whole concept of prodrugs seems intriguing on several levels.
I reluctantly agree we'll have to wait. Perhaps a similar prodrug version of
pregabalin or something else.... Anything to increase efficacy, reduce adverse effects/risks, ameliorate the suffering....
Doc