Ambien is a commonly used sleep aid. What isn’t commonly known is that there are a significant number of reported cases of people “sleep driving” after taking Ambien. In the recent case of People v Mathson a California Court of Appeal, for the first time, has ruled on a defense of sleep driving while under the influence of Ambien.
Mr. Mathson took Ambien at bedtime and later was found guilty by a jury of driving under the influence of drugs, a violation of California Vehicle Code (CVC) Section 23152(a). On appeal, the Court noted that voluntary intoxication is not a defense to driving under the influence. However, if after voluntary ingestion of a drug such as Ambien there is an unconscious act, like sleep driving, is it a crime? The Court stated the non-controversial rule that involuntary intoxication is a defense to CVC 23152(a). The controversial part of the ruling is that the Court suggested there be a jury instruction that states: “A person is involuntarily intoxicated if he or she willingly and knowingly ingested a prescribed drug and did not know or reasonably could not have known of the drug’s intoxicating effects”.
In essence the Court ruled that if the Defendant was aware or should have been aware of the side effect of Ambien, sleep driving, then it isn’t involuntary intoxication (which is a defense). However, if he didn’t know or have reason to know that Ambien could cause sleep driving, then even though Mathson voluntarily took the drug it was involuntary intoxication which is a defense to driving under the influence. Many factual differences occur in every case and while it is now clear that sleep driving can be defended successfully every case will turn on it’s own particular facts.