Morphine withdrawal is considered less dangerous than alcohol, barbiturate, or benzodiazepine withdrawal. Zopiclone has crosstolerance with barbiturates and is able to suppress barbiturate withdrawal signs. A similar syndrome may occur with benzodiazepine and barbiturate withdrawal. It contains butalbital, a barbiturate and paracetamol (acetaminophen), an analgesic. Both alcohol, barbiturate as well as benzodiazepine withdrawal can potentially be fatal. Overdose of barbiturate drugs can cause respiratory depression and death. A diagnosis is verified by a benzodiazepine or barbiturate test. The barbiturate most commonly used for this is phenobarbital. Sodium thiopental is an ultra-short-acting barbiturate that is marketed under the name Sodium Pentothal. Tong had died from an intentional barbiturate overdose. An Associated Press agency report said that of the barbiturate pentobarbital was administered. Primidone is an anticonvulsant of the barbiturate class. Monroe was also briefly hospitalized due to a barbiturate overdose. An autopsy identified his manner and cause of death as accidental acute barbiturate intoxication. Whippets are, like other sighthounds, intolerant of barbiturate anaesthetics.