Alcohol is a drug that is produced by natural fermentation mechanisms. It is legally available in the United Kingdom from licensed outlets to people aged over 18 years and is enjoyed and used safely by many people. However, alcohol is a major cause of health and social problems, and, after tobacco, causes more deaths in the United Kingdom than any other drug.

Alcohol relaxes the brain and body, and is normally drunk for its pleasant effects. Many people find that moderate drinking helps relieve stress, encourages relaxation and acts as an appetite stimulant. However, long-term heavy alcohol consumption can cause ill health, affecting the liver, heart and brain, and may worsen the brain impairment seen in some patients with HIV^[1][2]. Heavy alcohol use can also lead to physical and psychological dependence.

There is no evidence that moderate drinking does any harm to people with HIV. However, patients with hepatitis or high levels of blood fats may have to reduce their alcohol take or stop drinking alcohol altogether. Heavy drinking can also affect the immune system and may slow down recovery from infections.

A study in macaques has also suggested that alcohol abuse can lead to elevated viral loads, possibly increasing disease progression^[3][4]. While this relationship has not been observed in HIV-positive patients who are not taking antiretroviral therapy, heavy drinking has been linked to higher viral loads in those taking treatment, possibly due to problems with adherence^[5][6].

The liver damage that can occur with long-term heavy alcohol use can also interfere with the break-down of some antiretroviral drugs and can increase the likelihood of patients experience side-effects from anti-HIV drugs, particularly protease inhibitors^[7]. The blood fat increases caused by some anti-HIV drugs can also be made worse by heavy drinking.