A 51-year-old Reno doctor faces a maximum of up to 20 years in prison after pleading guilty to conspiring to illegally distribute opioids. Eric Math of Reno changed his earlier plea of not guilty Monday in U.S. District Court in Reno. A federal grand jury indicted Math and seven co-defendants on charges unsealed in May related to distribution of hydrocodone and oxycodone in the Reno area between October 2018 and May 2019. The others are scheduled to go to trial May 12.