Posted by SLS on October 25, 2015, at 8:00:29
In reply to Re: Fluvoxamine Abilify interaction, posted by Christ_empowered on October 25, 2015, at 7:19:21
The following reference should be accurate. However, the one scenario not addressed is that of a rapid metabolizer (rather than a poor metabolizer) subject to a CYP 2D6 enzyme inhibiting comedication. Here, the dosage adjustment of Abilify may require a smaller reduction. The best approach might be to begin with a 50% reduction in Abilify and titrate clinically by 5 mg/day every week until you attain an optimal response. Since you have already begun your titration at 10 mg/day (50% of your original 20 mg/day dose), your next move is to go to 15 mg/day. If you are a 2D6 rapid metabolizer, you may end up at 20 mg/day again.
Caucasians tend to be rapid metabolizers of CYP 2D6.
I find it interesting that the recommendation of not adjusting the dosage of Abilify when it is used to treat depression probably assumes a dosage of 2 - 5 mg/day.
- Scott------------------------------------------
http://www.drugs.com/dosage/aripiprazole.html
"Dose Adjustments...
CYP450 Dose Adjustments: Oral Formulations:
-Known CYP450 2D6 poor metabolizers (PM): Administer one-half usual dose
-Known CYP450 2D6 PM receiving concomitant strong CYP450 3A4 inhibitors: Administer one-quarter usual dose
-Concomitantly receiving strong CYP450 2D6 or 3A4 inhibitors: Administer one-half usual dose
-Concomitantly receiving strong CYP450 2D6 and 3A4 inhibitors: Administer one-quarter usual dose
-Concomitantly receiving CYP450 3A4 inducer: Double the usual dose over 1 to 2 weeks
IMPORTANT NOTES:-When coadministered drug is withdrawn, aripiprazole dose should be adjusted to the original level over 1 to 2 weeks.
-Patients receiving a combination of strong, moderate, and weak inhibitors of CYP450 3A4 and CYP450 2D6 may need an initial dose reduction to one-quarter of the usual dose with adjustments to achieve a clinical response.
-When aripiprazole is administered to patients with major depressive disorder, dose adjustments are not recommended."
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Some see things as they are and ask why.
I dream of things that never were and ask why not.- George Bernard Shaw
poster:SLS
thread:1083671
URL: http://www.dr-bob.org/babble/20150929/msgs/1083676.html