To test the suggestion that
chlorpropamide-alcohol flushing (
CPAF) resembles the
disulfiram effect and might be mediated by
acetaldehyde, the initial metabolite of alcohol, blood concentrations of
acetaldehyde were measured after a drink of alcohol in controls and diabetics positive and negative for
CPAF. The
CPAF-positive diabetics had significantly greater blood
acetaldehyde concentrations after alcohol than the
CPAF-negative diabetics both with a single dose of
chlorpropamide and after two weeks'
chlorpropamide treatment. Concentrations in the
CPAF-positive group after
chlorpropamide were also significantly greater than after a placebo
tablet. There was also a clear separation in the increase in facial temperature after two weeks of
chlorpropamide between the
CPAF-positive and
CPAF-negative groups (although there was some overlap after a single
tablet). There was no difference in plasma
chlorpropamide or alcohol concentrations between
CPAF-positive and
CPAF-negative diabetics. These findings show that
CPAF is distinct from alcohol
flushing and that the
acetaldehyde concentration in the blood provides an objective measure of
CPAF. The difference between
flushing and non-
flushing diabetics cannot be accounted for by differences in blood concentrations of
chlorpropamide or alcohol.