I cannot get high on codeine because I apparently lack the CYP2D6 enzyme but will I be able to take other opiates. I took 256mg of codeine yesterday with no tolerance and I couldn't feel a thing not one bit and I mainly fall for placebo's but in this case I'm for sure it didn't effect me. Is there anyone here that can't get high on codeine but can get high on other opiates like oxycodone?