#antidote
Antidotes are agents that negate the effect of a poison or 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. 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.
Mechanism of action of antidotes:
Reduction in free toxin level can be achieved by specific and non-specific agents that bind to the toxin.
The most commonly used non-specific binding agent is activated charcoal. Specific binders include chelating agents, bioscavenger therapy and immunotherapy.
In some situations, enhanced elimination can be achieved by urinary alkalization or hemadsorption. Competitive inhibition of enzymes (e.g. ethanol for methanol poisoning), enhancement of enzyme function (e.g. oximes for organophosphorus poisoning) and competitive receptor blockade (e.g. naloxone, flumazenil) are other mechanisms by which antidotes act.
Drugs such as N-acetyl cysteine and sodium thiocyanate reduce the formation of toxic metabolites in paracetamol and cyanide poisoning respectively.
Drugs such as atropine and magnesium are used to counteract the end-organ effects in organophosphorus poisoning. 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.
This review provides an overview of the role of antidotes in poisoning.
In this video and its affiliated parts in the miscellaneous section, multiple-choice questions about drugs and poisoning, are very important questions that you may encounter in many exams.
#toxic #drug #mcq
videos links:
MCQs of drugs used in disorders of coagulation part-1
[ Ссылка ]
MCQs of drugs acting on hematopoietic system part-1
[ Ссылка ]
MCQs of anxiolytics agents part-1
[ Ссылка ]
MCQs of pharmacology very important questions part-6
[ Ссылка ]
MCQs of Antihypertensive drugs part-1
[ Ссылка ]
MCQs of Antiparkinsonian drugs part-1
[ Ссылка ]
MCQs of Gastrointestinal diseases part-1
[ Ссылка ]
MCQs of CNS (Antiepileptics) part-1
[ Ссылка ]
MCQs of Antibiotics part-1.1
[ Ссылка ]
NAPLEX pass rate MCQs part-1
[ Ссылка ]
Killing Time by Kevin MacLeod is licensed under a Creative Commons Attribution 4.0 License. [ Ссылка ]
Source: [ Ссылка ]
Artist:
[ Ссылка ]
