Posted by Sunnely on June 4, 2001, at 23:43:34
In reply to Wellbutrin. Sustained Release vs Imediate, posted by Stephania on June 4, 2001, at 21:39:21
Hi Steph,
The main difference, IMHO, between Wellbutrin SR (sustained release) and Wellbutrin IR (immediate release) is in the degree of their peaks in blood concentrations. In contrast to the IR, the SR formulation avoids the rapid and high peaks in blood concentrations therefore, decreasing the risk of seizures.
In the early days of bupropion (Wellbutrin) when episodes of seizures were commonly reported, it was determined that the rapid and high peaks in blood concentrations were correlated with the occurence of seizures. Wellbutrin appears to reach its peak blood concentrations in 2-4 hours, the same period of time that seizures reportedly commonly occurred. As a result, Wellbutrin SR, with lesser high blood peak concentrations, was formulated. To further minimize the risk of seizures, it is recommended that Wellbutrin doses be taken at least 6-8 hours apart, and that each single dose of Wellbutrin be no more than 150 mg., which BTW, recommendations not always heeded by prescribers. (For example, for someone on Wellbutrin SR at 450 mg/day, will need to take this dose in 3 divided doses of 150 mg each single dose, at least 6-8 hours apart, such as 150 mg at 8:00 am, 2:00 pm, and 8:00 pm.) Of course, Wellbutrin is contraindicated in people with history of seizure or eating disorders because of their risk for seizures.
Not much difference in side effect profile between IR and SR formulation although the SR may be more gentle to your stomach. Based on the concerns described above, it will be clinically prudent for a doctor to prescribe the SR rather than the IR formulation.
On a final note, Wellbutrin SR is also Zyban (for smoking cessation) and therefore, should not be taken together, again, due to seizure concerns.
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> Hi all.
>
> What is the difference of the SR vs the imediate release? Are there different sides? How does a pdoc chose which is a good choice?
>
> Be well all. It has been a rough ajustment period! I am hanging on by a thread. My agitation is so bad:(
>
> Steph
poster:Sunnely
thread:65413
URL: http://www.dr-bob.org/babble/20010530/msgs/65437.html