The NHS recommend we consume no more than 14 units of alcohol per week. The average 70cl bottle of vodka equates to 28 units, so he could be having between 56 to 84. Way too much.
In respect of whether he is an alcoholic, carefully consider the diagnostic criteria and see what you think:
*"The Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) changed from differentiating Alcohol Abuse and Alcohol Dependence to a single category of Alcohol Use Disorder. DSM-5 criteria are as follows:
A maladaptive pattern of substance use leading to clinically significant impairment or distress, as manifested by 2 or more of the following, occurring at any time in the same 12-month period:
Alcohol is often taken in larger amounts or over a longer period than was intended.
There is a persistent desire or unsuccessful efforts to cut down or control alcohol use.
A great deal of time is spent in activities necessary to obtain alcohol, use alcohol, or recover from its effects.
Craving, or a strong desire or urge to use alcohol.
Recurrent alcohol use resulting in a failure to fulfill major role obligations at work, school, or home.
Continued alcohol use despite having persistent or recurrent social or interpersonal problems caused or exacerbated by the effects of alcohol.
Important social, occupational, or recreational activities are given up or reduced because of alcohol use.
Recurrent alcohol use in situations in which it is physically hazardous.
Alcohol use is continued despite knowledge of having a persistent or recurrent physical or psychological problem that is likely to have been caused or exacerbated by alcohol.
Tolerance, as defined by either of the following:
A need for markedly increased amounts of alcohol to achieve intoxication or desired effect.
A markedly diminished effect with continued use of the same amount of alcohol.
Withdrawal, as manifested by either of the following:
The characteristic withdrawal syndrome for alcohol
Alcohol (or a closely related substance, such as a benzodiazepine) is taken to relieve or avoid withdrawal symptoms."*