Rush Limbaugh has taken a 30-day leave of absence from his radio show to fight his addiction to painkillers. Last Friday on his show, he announced his addiction, and said he was immediately checking himself into a drub rehabilitation center. As for a report about alleged purchases of black-market painkillers, he acknowledged that authorities were conducting an investigation. Limbaugh said the accounts contained inaccuracies and he had been advised to limit public comment on the matter until the investigation was complete. He said he would clarify the stories when he could. His syndicator, Premiere, said it would use substitute hosts while Limbaugh was away.