Question from a Learning Circle member:
How would you transition from 900 mgs of quetiapine to clozapine. I know that both are sedating but never did this one.
Rajnish Mago, MD:
I see two issues here: what dose of clozapine would be equivalent to 900 mg of Seroquel and how to do the transition.
Dose equivalence of second generation antipsychotics is provided at https://simpleandpractical.com/second-generation-antipsychotics-dose-equivalents/
The clozapine dose would probably be a little less than the quetiapine dose, i.e., theoretically about 800 mg/day. Of course, with clozapine you will probably need less than that and will be guided by the clozapine level rather than simply by dose equivalence.
Re: cross-titration, since clozapine has to be titrated up slowly, I would delay reducing the quetiapine dose especially if the if the quetiapine has been even partially beneficial. So, start clozapine and only start reducing the quetiapine once the clozapine is above a certain dose. IF the person can tolerate taking 900 mg of quetiapine and clozapine 100-200 mg, it would be best to delay reducing the quetiapine.
If the quetiapine has not been helpful at all, you could start reducing it slowly after clozapine is at, say, 100 mg.
Of course, the specifics of doses would have to be tweaked based on response and tolerability.
Copyright 2016, Rajnish Mago, MD. All rights reserved. May not be reproduced in any form without express written permission.
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