The same number of pills would kill you or me. When the supply runs low, he surfs for unsuspecting doctors and clinics, feigning one malady or another, allegedly in need of pain killers. As usual, they oblige. Then he sells part of his stash in the underground marketplace in order to help finance his next set of prescriptions. When money gets real low, or when it's binge time, he'll sell his television, microwave, bicycle, stereo, Timex watch, mother's picture frame, whatever can bring enough cash to sustain the vicious cycle.
Jobs are spotty, working a few weeks at a time here and there in a breakfast house kitchen.
You see, after all these years of frying his brains, he has, in fact, become disabled. His hands shake, he suffers from anxiety and panic attacks, agoraphobia, liver disease. He lives in a dark hole. All that matters is today. Tomorrow is a long way off.