High agitation /Rage

My son is 30 years old with low functioning autism. He is currently in a violent rage cycle. In the few days previous to today he was cycling with 10 minutes of laughter, 10 minutes of silence, and then 10 minutes of rage only to start all over again. Today he immediately goes in to flapping , tapping, spitting  and then whacks the walls with pillows  if anyone even looks at or speaks to him.This could go on for weeks.
Right now he is on ketoconazole to address yeast issues again. Prior to this episode he was on Risperdal, Buspar, and Abilify. I thought his behaviors were increasing due to this drug combo , and putting him back on Risperdal did not seem to be helping matters. He is never depressed.His physical symptoms are severe chest pain (cardio tests all normal), tachycardia, diaphoresis, anxiety, tachypsnea, jumping  . He was wonderful during our summer and autumn of drought but the rainy weather patterns seem to have triggered this behavior and he is stuck.What to do next to help him? Any feedback is appreciated.
Eldermom

[Crystlas]

You might get better responses in the autism forum, with other folks going through similar situations.  This is the bipolar forum!  Good luck.