Vitamins such as vitamin K, folic acid and pyridoxine are used to antagonise the effects of warfarin, methotrexate and INH respectively in the setting of toxicity or overdose. Drugs such as atropine and magnesium are used to counteract the end-organ effects in organophosphorus poisoning. Drugs such as N-acetyl cysteine and sodium thiocyanate reduce the formation of toxic metabolites in paracetamol and cyanide poisoning respectively.

naloxone, flumazenil) are other mechanisms by which antidotes act. oximes for organophosphorus poisoning) and competitive receptor blockade (e.g. ethanol for methanol poisoning), enhancement of enzyme function (e.g. In some situations, enhanced elimination can be achieved by urinary alkalization or hemadsorption. Specific binders include chelating agents, bioscavenger therapy and immunotherapy. The most commonly used non-specific binding agent is activated charcoal.

Mechanism of action of antidotes: Reduction in free toxin level can be achieved by specific and non-specific agents that bind to the toxin. Antidote administration may not only result in the reduction of free or active toxin level, but also in the mitigation of end-organ effects of the toxin by mechanisms that include competitive inhibition, receptor blockade or direct antagonism of the toxin. Antidotes mediate its effect either by preventing the absorption of the toxin, by binding and neutralizing the poison, antagonizing its end-organ effect, or by inhibition of conversion of the toxin to more toxic metabolites. Introduction: Antidotes are agents that negate the effect of a poison or toxin. Indian Journal of Critical Care Medicine Volume 23 | Issue Suppl 4 | Year 2019ġ,2Medical Intensive Care Unit, Division of Critical Care, Christian Medical College, Vellore, Tamil Nadu, IndiaĬorresponding Author: Binila Chacko, Medical Intensive Care Unit, Division of Critical Care, Christian Medical College, Vellore, Tamil Nadu, India, Phone: +91 9600272412, e-mail: to cite this article Chacko B, Peter JV.

Antidote warfarin overdose