Experts from Yale University conducted a study and found: alcohol affects people with HIV differently. Patients with depressed immunity get drunk faster healthy individuals and other patients who are in remission of the disease.
The susceptibility of the organism to alcohol in HIV-patients is 25% higher. This means that such people requires a quarter less alcohol to get drunk.
The researchers also have an idea of what you described phenomenon may be linked. HIV weakens the entire body, which affects the speed of the process of intoxication - it lengthens.