Just some thoughts relayed to me by
@Hoosierfans regarding why Abilify might stop working:
Dose level of Abilify and amisulpride is important, as these compounds in effect act as completely different drugs at high doses levels, compared to low dose levels.
At low dose levels, these drugs boost the dopamine system; but at higher doses, they go into reverse, and start to inhibit the dopamine system. See
this post.
Since we are using a low-dose regimen to treat ME/CFS, presumably the benefits for ME/CFS come from a dopamine boost. So you would want to be careful not to take too much of the drug, and turn that dopamine boost into a dopamine block.
It may be that because of the long 3-day half life of Abilify, this can throw your dosing out. You may slowly increase your Abilify dose until you find what you think is the optimum level, based on observing ameliorations in ME/CFS symptoms.
But because it takes 12 to 15 days for Abilify blood levels to reach their steady state peak (when dosing any drug it always takes 4 or 5 half lives to reach steady state), two weeks later, Abilify blood levels may have gone too high, and you may now inadvertently be at a dose level where Abilify starts to block dopamine.
So this might explain why some people observe Abilify stops working for them.
If this is the case, then the solution would be to lower your dose a bit.
The metabolite of aripiprazole is dehydroaripiprazole, which is also active. This has an even longer half-life of nearly 4 days. Ref:
here. So dehydroaripiprazole will not reach steady state until 16 to 20 days of regular Abilify dosing.
Optimum dose levels are going to be different from one person to the next, because drug pharmacokinetics will be different in each individual: even when given the same dose, different people will attain different blood concentrations of the drug, depending on factors such as body weight, and the speed of liver detoxification.
