Vicodin/percs, any of the opiate pain killers can have that effect. Keep in mind most women don't want to get pounded on for 40 min and you get frustrated wanting to nut and it ain't happening. Some women get worried it's them and their attraction/performance if you don't nut within a reasonable time frame.
Also, opiates would be a bad idea for regular ejac control. For every action there is an opposite and equal reaction. Taking it regularly then not using it will cause hypersensitivity leading to PE.