( CNN ) Ohio is changing the drugs used in lethal injections , a move that will delay at least one execution scheduled for next month , the Ohio Department of Corrections and Rehabilitation said Thursday . The state will stop using the two-drug regimen of midazolam and hydromorphone , the department said in a press release . The drug combination was last used in January 2014 on convicted murderer Dennis McGuire . Witnesses said he convulsed and gasped about 10 minutes before he died . The McGuire execution was closely watched because midazolam , a sedative , and hydromorphone , a painkiller , had never been used in a U.S. execution . Ohio , like many states , was forced to find new execution drugs after European-based manufacturers banned U.S. prisons from using their drugs in executions -- among them , Danish-based Lundbeck , which manufactures pentobarbital . Ohio will add thiopental sodium , a drug the state used for lethal injections from 1999-2011 , the department said . Thiopental sodium and pentobarbital will be the only drugs used . JoEllen Smith , spokesman for the corrections department , confirmed that Ohio has 40 vials of midazolam set to expire April 1 . The release said the the February 11 execution of Ronald Phillips , and possibly others , will be postponed while Ohio secures a supply of pentobarbital and thiopental sodium . CNN is trying to reach Ohio officials for details about their decision . McGuire was convicted in 1994 of the rape and murder of 22-year-old Joy Stewart , who was seven months pregnant . CNN 's Dave Alsup contributed to this report .
Ohio will stop using midazolam and hydromorphone and start using thiopental sodium . The drugs were used in January 2014 on an inmate who gasped and convulsed before death .