A method for the determination of tetraethylthiuram disulphide (Antabus, Abstinyl) and diethyldithiocarbamate in blood and urine; some studies on the metabolism of tetraethylthiuram disulphide

Inhibition of copper-zinc superoxide dismutase activity by selected environmental xenobiotics

The function of Cu,Zn-SOD is to dismutate superoxide into hydrogen peroxide and oxygen. This task is fulfilled due to structural nuances of the enzyme. Many environmental xenobiotics have been proved to inhibit Cu,Zn-SOD. Those compounds could be found not only in industrial sewage, cigarettes and various chemical agents - some of them are used as drugs, drug production substrates or are the product of drug biotransformation. Cu,Zn-SOD exposition to these compounds leads to inhibition due to: copper ion chelation, unfolding the structure of the enzyme, affecting residues vital for activity maintenance. This review covers a selection of Cu,Zn-SOD inhibitors, referring to in vivo and in vitro study.

Rapid and sensitive on-line precolumn purification and high-performance liquid chromatographic assay for disulfiram and its metabolites

The disulfiram (Antabus) metabolites diethyldithiocarbamate, diethyldithiocarbamate methyl ester, carbon disulphide and bis(diethyldithiocarbamato) copper complex were quantitatively analysed from directly injected heparin plasma by reversed-phase high-performance liquid chromatography. The highly volatile metabolite, carbon disulphide, was converted to the methyl ester of dimethyldithiocarbamate before chromatography. The analytical procedure is simple and does not require sample preparation or addition of an internal standard, and the compounds are eluted from the columns in 15 min. After automated on-line precolumn enrichment, the parent compound and biotransformation products could be back-flushed and chromatographed on an ordinary reversed-phase column. The influence of plasma protein binding on the constituents in the precolumn enrichment step was also investigated. Dissociation and partition of constituents from plasma proteins gave a complete retardation on the precolumn. The time courses of diethyldithiocarbamate and its methyl ester were followed in patients receiving therapeutic doses of disulfiram.

Effect of diethyldithiocarbamate rescue on tumor response to cis-platinum in a rat model

The nephrotoxic effects of cis-dichlorodiamineplatinum(II) (NSC-119875) (DDP) in female F344 rats were effectively inhibited by administration of sodium diethyldithiocarbamate (DDTC) in doses of 750 mg/kg intraperitoneally or 100 mg/kg intravenously 2 hr after administration of DDP. Rats were inoculated with mammary tumor 13762 and treated after 10 days with DDP (2.0 or 8.0 mg/kg) with or without DDTC rescue (750 mg/kg intraperitoneally or 100 mg/kg intravenously). Initial reductions in tumor size were identical with or without rescue in all experiments. High-dose intraperitoneal rescue, however, resulted in earlier relapse and more rapid progressions at both DDP doses than was observed in the absence of rescue. Low-dose intravenous rescue led to a tumor response identical to that observed without rescue. Urinary excretion of free DDTC was increased by prior administration of acetazolamide; however, this combination was more toxic to rats after DDP administration than was DDTC alone. Intravenous administration of DDTC appeared to be the most effective route for delivery of this ligand to the kidney. These results support our earlier mechanistic hypothesis and demonstrate the feasibility of inhibition of cis-platinum toxicity by DDTC without inhibition of the antitumor effect.

Determination of disulfiram and metabolites from biological fluids by high-performance liquid chromatography

A high-performance liquid chromatographic method is described for the determination of disulfiram, diethyldithiocarbamate, diethyldithiocarbamate methyl ester, carbon disulfide, and diethylamine from a single sample of plasma or urine. The analytical procedure is based on a quantitative stepwise extraction of disulfiram and diethyldithiocarbamate methyl ester, or the conversion of diethyldithiocarbamic acid, carbon disulfide and diethylamine to diethyldithiocarbamate methyl ester for chromatographical determination. The procedure is specific, precise and simple. The application of the analytical methods developed for the determination of disulfiram and the various metabolites in plasma from mice given disulfiram intraperitoneally or humans given Antabuse orally is illustrated.

Inhibition of cis-platinum nephrotoxicity by diethyldithiocarbamate rescue in a rat model

The nephrotoxic effects of cis-dichlorodiammineplatinum(II) (NSC-119875) administered to male F344 rats at the median lethal dose (LD50; 7.5 mg/kg) were inhibited by treatment with sodium diethyldithiocarbamate (500 or 750 mg/kg) between 1 and 4 hr after cis-platinum administration. Those animals receiving cis-platinum alone had mean serum blood urea nitrogen levels of 234 mg/dl at the time of maximal toxicity (day 5); kidney sections revealed large areas of degeneration and necrosis. When dithiocarbamate rescue was carried out after cis-platinum treatment, mean blood urea nitrogen levels were in the range 56-95 mg/dl; kidney sections were grossly normal with a barely discernible band of degeneration at the corticomedullary junction. Gastrointestinal toxicity was observed in greater than 95% of the cis-platinum-treated rats but was totally absent in those receiving subsequent rescue treatment. A significant decrease in weight loss was also observed in the dithiocarbamate-rescued rats. Based on the chemistry of platinum-sulfur interactions and the observed time-dependence of the rescue treatment, it is suggested that dithiocarbamate exerts its effects via competitive chelation and removal of platinum coordinated to protein-bound sulfhydryl groups of the kidney tubule cells.

Tetraethylthiuram disulfide (Antabuse) inhibits the human malaria parasite Plasmodium falciparum

Plasmodium falciparum in culture grows optimally at 3% oxygen. Oxygen levels down to 0.5% still support growth, but anaerobic conditions do not. These findings, and the absence of the Krebs cycle in Plasmodium, suggested that in this organism oxygen may not function in electron transport but rather may act through metalloprotein oxygenases. Tetraethylthiuram disulfide (Antabuse, disulfiram) and its reduction product diethyldithiocarbamate inhibit many metalloprotein oxygenases and have a lipid/H2O partition coefficient and high binding constant for metal ions, favoring selective toxicity to the malaria parasite. These compounds exhibited active antimalarial effects in vitro in concentrations down to 0.1 microgram/ml, the lowest level tested. Tetraethylthiuram disulfide at a level as low as 1 microgram/ml inhibited parasite glycolysis with no effect on glycolysis of normal erythrocytes. Erythrocytes pretreated with this drug at 10 microgram/ml did not support growth of the parasite.

Method for the detection of diethylamine, a metabolite of disulfiram, in urine

Disulfiram is a drug used in the treatment of chronic alcoholism in man. Accurate assessment of patient compliance is important in this treatment. This paper describes a method for the detection and quantitative analysis of diethylamine, a metabolite of disulfiram, in urine. The method involves conversion of the water-soluble diethylamine in the urine to a derivative, N,N-diethyl-3,5-dinitrobenzamide, that is soluble in an organic solvent. This derivative is extracted from urine with diethyl ether and then subjected to thin-layer chromatography. A spectrophotometric procedure is used for quantification. This method provides a means of determining whether or not a patient is taking his prescribed disulfiram.