Excluding statement because high on large amounts of opiates

Generally speaking, voluntary intoxication is not a defense to an offense. The key issue here is whether you made a knowing and voluntary statement.   If you are able to prove your confession was not knowing or voluntary based upon your intoxication, you are entitled to have the evidence suppressed. However, Illinois Courts have generally been unwilling to suppress a confession based upon voluntary intoxication.  Its going to depend on the exact facts of the situation.