Who are you to this manic person? Shouldn't the psychiatrist be consulted?

If the person's current medication(s) isn't/aren't working, then I'd think higher doses or additions or changes to the medication(s) should be made. This should be up to the person's psychiatrist. The last resort, in some cases, could be ECT. I think in the case of severe mania, therapy has only very limited benefits. That's just my personal opinion as a patient whose been manic several times. I'm not a doctor or therapist. They should be consulted on this.

Quitting meds is not a good idea. I think that for many people with bipolar disorder that it is easier to control mania when medications are already in place rather than none at the start. Some bipolar medications require time and dosage/cocktail experiments to work.