This document discusses antidotes, which are substances that counteract toxins and poisons. It defines antidotes and explains that some are made by injecting toxins in animals and extracting resulting antibodies. The document classifies antidotes into physical, chemical, and pharmacological categories based on their mechanisms of action. It provides examples of specific antidotes for various toxins and poisons like paracetamol, morphine, cyanide, and more. The document aims to explain what antidotes are and how they work to neutralize different toxins.
2. • According to WHO “Antidote was defined as a
therapeutic substance used to counteract the
toxic action(s) of a specified xenobiotic.”
• Antidotes reduce the overall burden of health
service in managing of poisoning cases
3. INTRODUCTION
• An antidote is a substance thatcan
counteract a form of poisoning.The
term ultimately derives from the
Greek term (pharmakon) antidoton,
"(medicine) given as aremedy".
• Antidotes for anticoagulants are
sometimes referred to asreversal
agents.
4. INTRODUCTION
• The antidotes for some particular toxins are
manufactured by injecting the toxin into an animal in
small doses and extracting the
resulting antibodies from the host animals' blood. This
results in an antivenom that can be used to
counteract venom produced by certain species of
snakes, spiders, and other venomous animals. Some
animal venoms, especially those produced by
arthropods (e.g., certain spiders, scorpions, bees, etc.)
are only potentially lethal when they provoke allergic
reactions and induce anaphylactic shock; as such,
there is no "antidote" for these venoms because it is
not a form of poisoning and anaphylactic shock can
be treated (e.g., by the use ofepinephrine).
7. Physical Antidote:
• Agent use to interfere with poison
through physical properties, not
change their nature.
• a) Adsorbing: The main example is
activated charcoal.
• b) Coating: A mixture of egg & milk
make a coat over the mucosa.
• c) Dissolving: 10% alcohol or
glycerin for carbolic acid
8. Chemical Antidote:
Interact specifically with a toxicant,
or neutralize the toxicant. e.g.
metal chelators combine with
metals to form complexes that can
then be eliminated by the kidneys
Mainly act by twomechanisms:
Complex Formation: Antidote
make complex with the toxicant
making it unavailable to cross the
membrane or to interact with
receptors.
DMSA(dimercaprol and
dimercaptosuccinic acid are
sulfohydral compounds that bind
metal such as arsenic acid,lead.
9. Pharmacological antidote
counteract the effects of a
poison by producing the
opposite pharmacological
effects, e.g., ACHE
inhibitors,atropine.
•Pharmacologic antidotes
may neutralize or
antagonize the effects of a
toxicant.
•This type of antidote may
act by following 5
mechanism.
10. Some specific Antidotes for drugs and
chemicals
S.No. Agent causing toxicity Antidotes Dose
1. Paracetamol N-acetyl cysteine Oral =140mg/kg followed
by 70mg/kg even 4hrs,or
IV 150mg/kg infusion
over 15min. Repeated as
required.
2. Morphine andother
opoids
naloxone 1-2mg IV repeatedevery
10-15 minutes
3. heparin Protamine
sulphate
1mg iv for every100units
of heparin
4. cyanide sodium nitrate+
Sodium
thiosulfate
10 ml of 3% solutionIV
50 ml of 25% solution iv
11. Some specific Antidotes for drugs and
chemicals
S.No. Agent causing toxicity Antidotes Dose
5. Copper D-penicillamine 100mg/kg/day orally in 4
divided dose for 3-7 days
6. Iron Desferrioxamine 15mg/kg/hour IV
7. Arsenic Dimercaprol 1st day 400-800 mg deep
IM in divided dose 2nd and
3rd day 200-400mg.4th day
onwards 100-200mg.
8. Led calcium
disodium edetate
1 gram in 250mlsaline
infusion twice aday
12. Some specific Anidotes for drugs and chemicals
S.No. Agent causing toxicity Antidotes Dose
9. Insulin Glucose 50ml of 50% solution
10. Mathanol, ethylene
glycol
Ethanol 10% ethanol is givenorally
11. Carbon monoxide Oxygen 100% by high flownon-
rebreathing mask
12. Nitrites Methyline blue 0.1% solution slow IV in
the dose of 1-2 mg/kg
body weight
13. Some specific Antidotes for drugs and chemicals
S.No. Agent causing toxicity Antidotes Dose
13 Warfarin Vitamin K 1 oxide 10mg IM followed by 5mg 4
hrly asrequired
14 Benzodiazepines Flumazenil 0.2 mg IV repeatedas
required (max. 3mg)
15. Caffeine Esmolol 25-50µ/kg/min-IV
16. Atropine physostigmine 1-2mg IV slowly may be
repeated if symptoms re-
appear.