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Dear readers
We want to conduct biostudy for venlafaxine 100 mg tablets. The most
common
adverse effect encountered with this drug is nausea and vomiting. and
once
volunteer vomits out within 2 times of Tmax period, we have to drop him
from
study. so, how biostudy can be designed for this formulations? Is it
require to administer drug product with antiemetic drug?
Thanks and regards
Mitesh Gandhi
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Dear Mr Gandhi,
Supposing a Bioequivalence/Bioavailability study, the best choice would
be
the inclusion of an extra number of volunteers (or spare subjects) to
accomplish the correct size population for the study statistics. You can
calculate missing subjects and extra volunteers required from
literature or
your data.
Of course, avoiding use of any antiemetic because in that case you could
have an interaction drug study, but not a pure BEQ study.
Kind regards
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Dear Mr.Gandhi,
You will not get the vomiting in all the volunteers within stipulated
time period. So, to take care the proper sample size at the end of the
study you may take some extra volunteers. After dosing, engage the
volunteers in some activities, it may delay the chances of side
effects. To administer anti-emetic is not advisable because it may
cause drug interactions.
Dr. Nirav Gandhi
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Dear Mitesh,
You can plan a fed study instead of fasting. Venlafaxin is recommended
to be admistered with food. This will certainly reduce the number of
dropouts due to emesis. As mentioned by the others members in the
group, administration of antiemetic drugs is not recommended and will
not serve the purpose of BE study.
Kind Regards
Himanshu
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Dear Dr Nirav
Thanks for ur kind inputs. As you said, making volunteers engaged in
other
activities might delay chances of vomiting, but not reduce the chances
of
vomiting.
Is it acceptable if we do study with venla 50 mg CF instead of 100 mg
CF and
can we get biowaiver of 100 mg ? is it acceptable by FDA?
Thanks and regards
Mitesh Gandhi
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Dear Mitesh,
Please refer to the clinical toxicological review available ( the link
below, under adverse event section). It clearly states that nausea can
be minimised either by starting the therappy with low dose or by taking
the drug with food.
http://www.maripoisoncenter.com/ctr/9903venlafazine.html
Kind regards,
Himanshu
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Dear Mitesh,
I have been following the discussion with interest. While it is not
very common to administer anti-emetic drugs to prevent vomiting, it is
done in some cases. Classic example being Bromocriptine...where it is
nearly impossible to do the BE without anti-emetic. I would suggest you
look in to the FOI data of innovator to check his strategy,and you may
consider a controlled correspondence with FDA to ensure regulatory
compliance of your strategy.
Regards,
Sunil Vandse
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Dear Mitesh,
I doubt whether FDA would accept a BE study on venlafaxine 50mg tables;
because the RLD strength for venlafaxine tablets in the orange book is
100mg.
regards
kaushal prajapati
torrent pharmaceuticals limited
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