Posted by Sunnely on August 15, 2000, at 1:11:23
In reply to Wellbutrin vs Wellbutrin SR, posted by TomV on August 14, 2000, at 21:52:41
> Anyone tried both? Is SR superior to immediate release Wellbutrin. I've tried immediate release in the past and had very limited success. Any info would be appreciated.
TomV,
There are differences and similarities between the traditional immediate release (IR) and sustained release (SR) Wellbutrin (bupropion).
First, for the simlarities:[1,2]
1. The SR Wellbutrin is bioequivalent to the IR formulation and therefore, expected to have similar antidepressant effectiveness given in comparative doses.
2. As with the IR formulation, the SR formulation of Wellbutrin has minimal impact on sexual function. In fact, both formulations may have a "pro-sexual" effect.
3. Both the IR and the SR formulations are contraindicated in patients with seizure disorder, in patients with eating disorder (anorexia and bulimia), or in patients on monoamine oxidase inhibitors (MAOIs) such as phenelzine (Nardil), tranylcypromine (Parnate), and isocarboxazid (Marplan).
4. No matter what the formulation is (IR or SR), Wellbutrin may not be the best antidepressant for patients with anxiety. It is actually a very bad anti-anxiety drug - it has no anti-anxiety effect. If anything, it tends to increase anxiety symptoms.
5. Both formulations seem to work well for patients with atypical type of depression - those who are sleeping and eating too much. In fact, both formulations may decrease appetite and induce weight loss.
Now for the differences:[1,2]
1. Frequency of dosing: With the SR formulation, it only has to be taken twice a day, although one reknown psychopharmacologist would disagree with this, i.e., depending on the total daily dose.[2]
2. Side-effect profile: The SR formulation seems to have fewer negative side effects such as insomnia, restlessness, and gastrointestinal distress compared to the IR formulation. It was suggested that the degree of side effects with Wellbutrin is related to the (blood) peak levels. The SR formulation decreases those peak levels, so the negative side effects described above would be less. Similarly, lessening the peak levels of Wellbutrin (using SR) also lessens the chance of seizures.
3. You can substitute Wellbutrin SR for Zyban (smoking cessation), but not Wellbutrin IR for Zyban. Wellbutrin SR is the spitting image of Zyban. The manufacturer, Glaxo Wellcome, gave Zyban a different name than Wellbutrin SR to distinguish the two uses of the drug. Another reason for the name change is just because of the stigma of depression, unfortunately.
To lower the risk of seizures from Wellbutrin, as an antidepressant, the following guideline is recommended:
1. The dose should be carefully titrated (increased) to achieve the lowest effective dose.
2. Daily doses (except for starting doses) are to be divided into at least every 6 or 8 hours interval.
3. The dose should not exceed 450 mg/day.
4. The dose should not exceed 150 mg in any single dose.
5. The doses should not be given closer than every 6 hours.
6. Further dose increases should not occur any more frequently than every 3 days, and for no more than 100 mg.
References:
1. Benefits of new sustained-release bupropion: less-frequent dosing, fewer side effects. In: Psychopharmacology Update, November 1997.
2. Preskorn SH: Bupropion. Journal of Psychiatric Practice, January 2000.
poster:Sunnely
thread:42902
URL: http://www.dr-bob.org/babble/20000811/msgs/42921.html