Use Google and you will easily locate articles discussing cases of overdose-like symptoms in patients taking Methadone who were then started on Fluvoxamine. In one case, the overdose symptoms popped up around day 5 of Fluvoxamime induction.
I can say that it works. I've done it. It is in a different league than things like Grapefruit or even Cimetidine (Tagamet).
The only problem is that you would then be taking an SSRI. The effects of SSRIs can be difficult to deal with, especially the libido issues.