An alcohol abuser claims that the intake of ascorbic acid (vitamin C) increases the excretion of An

Fråga: An alcohol abuser claims that the intake of ascorbic acid (vitamin C) increases the excretion of Antabus (disulfiram), so that one can start drinking alcohol again sooner. Is there any documentation to support this thought?

Sammanfattning: No documentation could be found concerning a possible enhancing effect of ascorbic acid on disulfiram clearance.

Svar: Disulfiram is thought to have a catalyzing action on the inactivation of the enzyme aldehyde dehydrogenase, such that after intake of alcohol, the accumulation of acetaldehyde occurs with the development of unpleasant side effects. The inhibition of aldehyde dehydrogenase develops slowly, with a maximum effect being seen at 48 hours. Restoration of enzyme activity depends on de novo synthesis which occurs over six or more days (1). Disulfiram is extensively metabolised, mainly to diethyldithiocarbamate (DDC), which also has inhibiting effects on aldehyde dehydrogenase in vivo. Fifty per cent of a disulfiram dose is excreted in the urine as DDC glucuronide (1).

We did not find any documentation indicating that ascorbic acid could enhance the elimination and/or excretion of disulfiram. According to an animal study (2) in which both alcohol and disulfiram were administered in high doses (1-2 g/kg) to rats, it was found that concomitant administration of ascorbic acid (6.7 mg/kg) did not have any significant influence on the rise of acetaldehyde levels.

Ascorbic acid may, however, increase the elimination of alcohol (3,4). In a study investigating the influence of ascorbic acid pretreatment on ethanol clearance, toxicity and behavioral impairment, 5 gram of ascorbic acid or placebo was given per os in a double-blind cross-over design to 20 male subjects for two weeks before the consumption of ethanol. The ascorbic acid dose was considered the highest possible to be safely given to healthy subjects. The ethanol dose was 0.95 g/kg and consumed in 2.5 hour. It was found that ethanol clearance was increased (p = 0.02) by 10 to 74 per cent in 10 subjects, increased by one to 10 per cent in four subjects, decreased by one to 10 per cent in five subjects and unchanged in one subject. It was hypothesized that ascorbic acid could enhance ethanol clearance by generation of a peroxide that is used by catalase in a peroxic oxidation of ethanol. Normally, the contribution of catalase to ethanol oxidation in vivo is thought to be insignificant. Another study reports a slight enhancement of ethanol clearance after ascorbic acid was administered in a dose of 1.0 gram per day for two weeks. 1 Dollery, Therapeutic Drugs, 1991; 1: D188-D190 2 Freundt KJ, Heiler C, Schreiner E: Ferrous sulfate combined with ascorbic acid does not significantly reduce acetaldehyde accumulation in the blood of alcoholized rats treated with disulfiram or betalactam antibiotics. Alcohol 1990; 7: 295-298 3 Susick RL, Zannoni VG: Effect of ascorbic acid on the consequences of acute alcohol consumption in humans. Clin Pharmacol Ther 1987; 41: 502-509 4 Hansten, Horn, Drug interactions & Updates, 1971-