This drug produce an acute sensitivity to ethanol (drinking alcohol). Disulfiram works by inhibiting the enzyme acetaldehyde dehydrogenase, which cause many of the effects of a hangover to be felt immediately following alcohol consumption. Disulfiram should be used in conjunction with counseling and support.
The main use of Disulfiram is to treat chronic alcoholism. It causes unpleasant effects when even small amounts of alcohol is consumed. Effects such as flushing of the face, headache, nausea, vomiting, chest pain, weakness, blurred vision, mental confusion, sweating, choking, breathing difficulty, and anxiety. These effects begin about 10 minutes after the consumption of alcohol and last for 1 hour or more. Disulfiram is not a exact cure for alcoholism, but discourages drinking.
When alcohol is ingested after administration of disulfiram, blood acetaldehyde concentrations are increased, followed by flushing, systemic vasodilation, respiratory difficulties, nausea, hypotension, and other symptoms acetaldehyde syndrome. It acts by inhibiting aldehyde dehydrogenase.
Indications
Disulfiram Tablets is indicated for the chronic alcohol patients who want to remain in a state of enforced sobriety so that supportive and psychotherapeutic treatment may be applied to best advantage.
Pharmacology
Mechanism of action:
Disulfiram is an oral drug. The main use of this drug is to treat alcoholism. Alcohol is converted in the body into acetaldehyde by an enzyme known as alcohol dehydrogenase. Another enzyme called acetaldehyde dehydrogenase then it converts acetaldehyde into acetic acid. Disulfiram prevents acetaldehyde dehydrogenase from converting acetaldehyde into acetic acid, leads to buildup of acetaldehyde levels in the blood.
Disulfiram blocks the oxidation of alcohol at the acetaldehyde stage during metabolism of alcohol following disulfiram intake causing an accumulation of acetaldehyde in the blood producing highly unpleasant symptoms. Disulfiram works by blocking the oxidation of alcohol through its irreversible inactivation of aldehyde dehydrogenase, which acts in the second step of ethanol utilization. Disulfiram competitively binds and inhibits the peripheral benzodiazepine receptor, which is helpful in the treatment of the symptoms of alcohol withdrawal.
Pharmacodynamics:
Antialcoholic action: Disulfiram inhibits aldehyde dehydrogenase, which prevents the oxidation of alcohol after the acetaldehyde stage. It interacts with ingested alcohol to produce acetaldehyde levels five to ten times higher than are produced by normal alcohol metabolism. Excess acetaldehyde produces a highly unpleasant reaction nausea and vomiting to even a small quantity of alcohol. Tolerance to disulfiram doesn’t occur; rather, sensitivity to alcohol increases with longer duration of therapy.
Disulfiram produces a sensitivity to alcohol which results in a highly unpleasant reaction when the patient under treatment ingests even small amounts of alcohol. Disulfiram blocks the oxidation of alcohol at the acetaldehyde stage during alcohol metabolism following disulfiram intake, the concentration of acetaldehyde which occurs in the blood may be 5 to 10 times higher than that found during metabolism of the same amount of alcohol alone. Disulfiram does not appear to influence the rate of alcohol elimination from the body. Prolonged administration of disulfiram does not produce tolerance; the longer a patient continues therapy, the more exquisitely sensitive he becomes to alcohol.
Pharmacokinetics:
Absorption:Disulfiram is absorbed completely after the oral administration, approximately 3 to 12 hours may be required before effects occur.
Distribution: It is Highly lipid-soluble and initially localized in adipose tissue.
Metabolism: Disulfiram Mostly oxidized in the liver and excreted in urine as free drug and metabolites, such as diethyldithiocarbamate, diethyl-amine, and carbon disulfide.
Excretion: About 5% to 20% is unabsorbed and eliminated in feces. A small amount is eliminated through the lungs, but most is excreted in urine. It takes Several days to eliminate drug entirely.
Contraindications & Precaution:
This medication is contraindicated with psychoses, myocardial disease, coronary occlusion, or hypersensitivity to disulfiram or to other thiuram derivatives used in pesticides and rubber vulcanization; and also in the patients receiving metronidazole, paraldehyde, alcohol, or alcohol-containing preparations.
Disulfiram is Used with extreme caution in patients with diabetes mellitus, hypothyroidism, seizure disorder, cerebral damage, or nephritis or hepatic cirrhosis or insufficiency and with concurrent phenytoin therapy.
Pregnant patients: Don’t use drug in pregnant patients or during pregnancy.
Side Effects:
Very rare but the common side effects are:
● skin rash,acne
● mild headache
● drowsiness
● tiredness
● impotence
● metallic taste or garlic-like taste in the mouth
● excessive tiredness
● weakness,lack of energy
● loss of appetitie,upset stomach
● vomiting
● yellowness of the skin or eyes
● dark urine