Effect of abstinence on the blood acetaldehyde response to a test dose of alcohol in alcoholics.

Following an acute dose of alcohol (0.15 g/kg intravenously), blood levels of acetaldehyde were significantly higher in nonabstinent alcoholics than in controls. After 2 weeks of abstinence, this blood acetaldehyde response significantly decreased in alcoholics and the acetaldehyde returned towards levels comparable to those observed in nonalcoholics. These results suggest that elevated blood acetaldehyde levels in the alcoholics are secondary to the chronic alcohol consumption rather than reflecting a primary preexisting defect.