sentences:  If necessary, the drugs can be ingested via a drinking straw.The pentobarbital overdose depresses the central nervous system, causing the person to become drowsy and fall asleep within 3–5 minutes of drinking it.Anaesthesia progresses to coma and later, as the person's breathing becomes more shallow, is followed by respiratory arrest and death, which occurs within 30–40 minutes of ingesting the pentobarbital.