Human alcohol self-administration studies with oral drinking are flawed by the high
variability of resulting breath alcohol concentrations (BrAC). We seek to develop
a paradigm with better control over achieved BrAC.
We performed a pilot study to test whether healthy subjects are able to understand
and use CASE to self-administer alcohol. The CASE system involves intravenous infusion
of 6 % ethanol in Ringer's solution via a computer-controlled infusion pump. Subject
are guided through the experiment by a computer screen and can order „drinks“ any
time by pressing a button, or abstain as long as they want. The Freibier paradigm
implies that subjects get as much alcohol as they like for free, i.e. without work,
pay or other prerequisites. After a short priming period, BrAC rises by exactly 0.075
‰ upon each button press and declines by 0.01 ‰ per minute thereafter until the next
drink is requested. 11 subjects participated in 3 sessions each.
Subjects achieved a fairly stable BrAC plateau for prolonged periods of time in most
sessions, ranging between 0.25 and 1.0 ‰. The maximum and plateau BrAC varied considerably
between the 1st and 2nd test, but was stable between 2nd and 3rd session in most of the subjects.
These preliminary data suggest that CASE is a practicable method to investigate human
alcohol self-administration and produces considerable alcohol exposure. Its readout
appears to be reliable, bearing the potential of being used for scientific questions.
Disclosure: This work was supported by NIAAA Grant No. P60 AA007611-20.
