The effects of alcohol vary with age. Even small amounts of alcohol can create problems for older people because as the body ages, the effects of alcohol can become amplified. Slower reaction times, problems with hearing and seeing, and a lower tolerance to alcohol's effects put older people at higher risk for falls, car crashes, and other types of injuries that may result from drinking.
Older people also tend to take more medications than younger people. Mixing alcohol with over-the-counter or prescription medications can be very dangerous, even fatal. Alcohol may worsen the effectiveness of medications and even worsen symptoms. For example, alcohol can increase bleeding for a patient taking a blood thinner. In addition, alcohol can make many of the medical conditions common in older people, including high blood pressure and ulcers, more serious. Physical changes associated with aging can make older people feel "high" even after drinking only small amounts of alcohol. So even if there is no medical reason to avoid alcohol, older men and women should limit themselves to one drink per day.
Possibly. More than 150 medications interact harmfully with alcohol. These interactions may result in increased risk of illness, injury, and even death. Alcohol's effects are heightened by medicines that depress the central nervous system, such as sleeping pills, antihistamines, antidepressants, anti-anxiety drugs, and some painkillers. In addition, medicines for certain disorders, including diabetes, high blood pressure, and heart disease, can have harmful interactions with alcohol. If you are taking any over-the-counter or prescription medications, ask your doctor or pharmacist if you can safely drink alcohol.
It depends. If that person has been diagnosed as an alcoholic, the answer is "no." Alcoholics who try to cut down on drinking rarely succeed. Cutting out alcohol--that is, abstaining--is usually the best course for recovery. People who are not alcohol dependent but who have experienced alcohol-related problems may be able to limit the amount they drink. If they can't stay within those limits, they need to stop drinking altogether.
Source: National Institute on Alcohol Abuse and Alcoholism