A person who is in an intoxicated condition is criminally responsible for his conduct and an intoxicated condition is not a defense to any offense and may not be taken into consideration in determining the existence of a mental state which is an element of the offense unless the defendant proves that he did not know that it was an intoxicating substance when he consumed, smoked, sniffed, injected or otherwise ingested the substance causing the condition.
Idaho Code § 18-116