Hello and welcome.
I think that it is great that you have consuted your doctor about
weaning off your Sertraline Rx. So many people attempt to do it themselves, or simply stop...and this is never a good idea.
It sounds like you have a plan in place, and if you tolerated the 50% initial cut well (lightheadedness can be expected)...you should continue to do fine with the reductions.
I can't answer your other question regarding your Dantroline. I know nothing about
this med, or how it will be to wean in combination with your A/D.
Please consult your prescribing doctors, as well as your pharmacist. They can all direct you in how to proceeed.
Wishing you the best in your cessation process. Post anytime!
Scaredy Cat
p.s. just to be on the safe side...keep an eye on your BP if your lightheadedness continues.:)