Causes of death in someone who has died while intoxicated:
(1) acute alcohol poisoning (from excessive alcohol ingestion in a short period)
(2) mixed alcohol and drug intoxication
(3) "swallowed" tongue while on lying supine
(4) obstructed airway (from food bolus)
(5) massive aspiration
(6) diabetic ketoacidosis
(7) seizure
(8) trauma, especially head injury
(9) acute myocardial infarction
(10) cardiac arrhythmia
(11) acute hepatic failure
(12) sepsis
(13) homicide (smothering, poisoning, etc)
(14) suicide
Toxicology studies can be very helpful in identifying:
(1) a high blood alcohol concentration (this is more significant in a non-alcoholic than in a chronic alcoholic)
(2) sedatives or other drugs
(3) unexpected medications
It is also important to realize that a person thought to be intoxicated by onlookers might be suffering from something completely unrelated to drugs or alcohol.