Automatism induced by alcohol or drugs is, as a matter of public policy, incapable of being a legal defence.  This is generally because there is a high number of crimes committed under the influence of alcohol, and increasingly nowadays drugs, which would otherwise go unpunished.  In R v Lipman [1969] the defendant was convicted of the manslaughter of a girl who he had killed whilst under the influence of LSD.  In confirming the conviction, the Court of Appeal held that mental states induced by drink or drugs are no defence to a charge of manslaughter, which, in any event, is an offence that does not require specific intent. 

Although automatism induced voluntarily through alcohol or drugs may indeed cause the defendant to act involuntarily or be unaware of what he was doing, it cannot normally be a complete defence.  However, there may be a partial defence in such circumstances if the accused is charged with an offence that requires a specific intent which the alcohol or drugs negated.  Often, however, serious charges which require specific intent are often coupled with lesser charges which do not. 

 http://www.inbrief.co.uk/court-proceedings/automatism-as-a-criminal-defence.htm

Automatism, in toxicology, refers to a tendency to take a drug over and over again , forgetting each time that one has already taken the dose.

Pharmacists may be alerted to drug automatism as a potential problem in patients who they suspect have memory problems (hinted by other prescriptions known to be for such problems), or attempts to re-fill prescriptions early (before next regularly scheduled due date for re-filling).

Automatism induced by alcohol or drugs is, as a matter of public policy, incapable of being a legal defence.  This is generally because there is a high number of crimes committed under the influence of alcohol, and increasingly nowadays drugs, which would otherwise go unpunished.  In R v Lipman [1969] the defendant was convicted of the manslaughter of a girl who he had killed whilst under the influence of LSD.  In confirming the conviction, the Court of Appeal held that mental states induced by drink or drugs are no defence to a charge of manslaughter, which, in any event, is an offence that does not require specific intent. 

Although automatism induced voluntarily through alcohol or drugs may indeed cause the defendant to act involuntarily or be unaware of what he was doing, it cannot normally be a complete defence.  However, there may be a partial defence in such circumstances if the accused is charged with an offence that requires a specific intent which the alcohol or drugs negated.  Often, however, serious charges which require specific intent are often coupled with lesser charges which do not. 

 http://www.inbrief.co.uk/court-proceedings/automatism-as-a-criminal-defence.htm

Barbiturate automatism—myth or malady?

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2466130/

an old article but interesting

Automatism is a mechanical repetitive indirect behavior that is unconsciously controlled, this is why it is also called automatic behavior. It is usually classified to: 1) sane automatism , and  2) Insane automatism that is associated with psychiatric disease.

The etiology can be due to cerebral disease, epilepsy, hypoglycemia or toxic due to drugs like sedatives and barbiturates, this type is called drug automatism ( repetitive intake of a drug due to drug induced drowsiness or amnesia ).

APC Textbook of Forensic Medicine and Toxicology - Anil Aggrawal

Automatism, in toxicology, refers to a tendency to take a drug over and over again , forgetting each time that one has already taken the dose. Barbiturates are an example of that.

Dear Ali! Dear all! I propose to compare the scientific understanding over the years about the side effects of barbiturates. Please open the article in the attachment.