Posted by gadman on March 12, 2005, at 21:40:14
In reply to Re: Effexor XR vs Effexor Immediate Release, posted by SLS on March 12, 2005, at 21:26:27
Thanks Scott... I just wish they made an 50 mg XR version... I wouldn't have to be messing with this...
The answer lies in the below text... I am just trying to decipher it right now. Time to max concentrations for XR is 5.5 hours and 2 hours for immediate release... I am assuming that means XR is delaying the release only by 3.5 hours?
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Administration of Effexor XR (150 mg q24 hours) generally resulted in lower Cmax (150 ng/mL
for venlafaxine and 260 ng/mL for ODV) and later Tmax (5.5 hours for venlafaxine and 9 hours
for ODV) than for immediate release venlafaxine tablets (Cmax’s for immediate release 75 mg
q12 hours were 225 ng/mL for venlafaxine and 290 ng/mL for ODV; Tmax’s were 2 hours for
venlafaxine and 3 hours for ODV). When equal daily doses of venlafaxine were administered as
either an immediate release tablet or the extended-release capsule, the exposure to both
venlafaxine and ODV was similar for the two treatments, and the fluctuation in plasma
concentrations was slightly lower with the Effexor XR capsule. Effexor XR, therefore, provides a slower rate of absorption, but the same extent of absorption compared with the immediate release tablet.
poster:gadman
thread:470163
URL: http://www.dr-bob.org/babble/20050312/msgs/470280.html