How Do Other Antidotes Work?

Antidotes are medications administered to counter the effects of poisons and drugs, and also to treat certain diseases. Other antidotes are medications that are not categorized into any specific classes of antidotes. Other antidotes include several drugs which work in unique ways to neutralize the harmful effects of diverse types of toxic substances.

Other antidotes include the following:

• Acetylcysteine (antidote): Acetylcysteine is used to treat and prevent liver damage from acetaminophen (analgesic) overdose. Acetylcysteine is an antioxidant that scavenges free radicals, and it also helps increase the liver’s levels of glutathione, a natural antioxidant in the body. Acetylcysteine is also used to break up mucus in the respiratory tract.
• Activated charcoal: Activated charcoal is administered as an antidote for poisoning and drug overdose. Activated charcoal binds to (adsorbs) a variety of chemicals and drugs in the gastrointestinal tract and is excreted naturally.
• Ethanol: Ethanol (ethyl alcohol), used to make drinking spirits, is an antidote for poisoning from methanol and ethylene glycol, toxic types of alcohol used in industries. Ethanol saturates the liver enzyme, alcohol dehydrogenase that breaks down alcohols, and prevents the breakdown of methanol and ethylene glycol into their toxic metabolites.
• Obiltoxaximab: Obiltoxaximab is a lab-made monoclonal antibody used as an antidote for anthrax toxins secreted by Bacillus anthracis, after an inhalational anthrax infection. Obiltoxaximab binds to the protective antigen, the protein component that activates the anthrax toxins, and prevents the production of toxins.
• Anthrax immune globulin: Anthrax immune globulin is a purified blood product with antibodies, prepared from plasma collected from healthy adults vaccinated for anthrax. Anthrax immune globulin binds to the protective antigen of Bacillus anthracis and neutralizes the anthrax toxins. 
• Botulinum antitoxin, heptavalent: Botulinum antitoxin, heptavalent (BAT) is a sterile solution of antibodies prepared from the plasma of horses immunized against seven types of botulinum toxins (A, B, C, D, E, F, and G). BAT provides immediate immunity against botulinum toxins produced by Clostridium botulinum, C. butyricum and C. baratii bacteria. 
• Botulism immune globulin IV: Botulism immune globulin is a purified blood product containing antibodies, prepared from plasma collected from healthy adults immunized against botulinum neurotoxins A and B. Botulism immune globulin antibodies bind to and neutralize A and B types of botulinum neurotoxins.
• Calcium chloride: Calcium chloride is a compound of calcium and chlorine and is used as an antidote to magnesium toxicity, an overdose of certain blood pressure medications such as calcium channel blockers and beta-blockers, and to treat conditions associated with hypocalcemia (low blood calcium level) and hyperkalemia (high potassium).
• Calcium gluconate: Calcium gluconate is a calcium salt used for similar conditions as calcium chloride. Both calcium gluconate and calcium chloride are used to restore the proper balance between the three minerals calcium, potassium, and magnesium, essential for the normal functioning of cardiovascular, muscular, and nervous systems. 
• Digoxin immune FAB (antidote): Digoxin immune FAB is a sterile preparation of antibody fragments obtained from sheep immunized with a digoxin derivative and is used to treat digoxin overdose. Digoxin is a drug prescribed to treat heart failure and abnormal heart rhythms (arrhythmias) and digoxin immune FAB is used to reverse its effects.
• Prussian blue: Prussian blue is an insoluble blue pigment produced from the oxidation of ferrous ferrocyanide salts, used as an antidote to contamination from heavy metals cesium and thallium. Prussian blue binds to cesium and thallium in the gastrointestinal tract after ingestion, reduces their reabsorption, and facilitates their elimination in feces.
• Fomepizole: Fomepizole is an antidote for poisoning from methanol and ethylene glycol, toxic types of alcohol used in industries. Fomepizole inhibits alcohol dehydrogenase, the liver enzyme that breaks down alcohols, and prevents the breakdown of methanol and ethylene glycol into their toxic metabolites.
• Glucarpidase: Glucarpidase is an enzyme used as an antidote to nephrotoxicity from methotrexate, a chemotherapy drug. Glucarpidase converts methotrexate into its inactive metabolites, providing a nonrenal elimination route in patients with impaired kidney function, who are undergoing high-dose methotrexate treatment.
• Hyaluronidase: Hyaluronidase is a protein enzyme used to reverse the effects of leakage of injected medications from blood vessels (extravasation), which can damage the tissue. Hyaluronidase modifies the permeability of connective tissue and improves dispersion and absorption of locally injected drugs and prevents extravasation.
• Idarucizumab: Idarucizumab is a humanized monoclonal antibody fragment (FAB) used to reverse the effects of dabigatran, an anticoagulant medication. Idarucizumab binds to dabigatran and its metabolites and neutralizes their anticoagulant effects. 
• Potassium iodide: Potassium iodide is a salt of stable iodine and is used during environmental radiation emergencies to protect the thyroid gland from radiation injury. Potassium iodide saturates the thyroid and prevents the absorption of radioactive iodine, but it cannot protect other parts of the body. Potassium iodide reduces thyroid hormone secretion and is used to treat hyperthyroidism and thyrotoxic crisis (thyroid storm).
• Ipecac syrup: Ipecac syrup is made from the root of the ipecac plant and was used in the past to empty the stomach contents after poisoning. Ipecac is a gastric irritant and stimulates the brain to induce vomiting. Ipecac syrup is no longer available or recommended for poisoning, activated charcoal is the current treatment of choice.
• Leucovorin: Leucovorin is an analog of vitamin B9 (folate) essential for DNA/RNA synthesis. Leucovorin is used to protect healthy cells from the harmful effects of chemotherapy drugs such as methotrexate and 5-fluorouracil (5FU), and enhance their toxic effects on cancer cells. Leucovorin is also used in methanol poisoning to eliminate formic acid, its toxic metabolite, and to treat anemia due to vitamin B deficiency. 
• Levoleucovorin: Levoleucovorin is also a form of folate and works similar to leucovorin. Levoleucovorin is used to counter chemotherapy effects but is not used in the treatment of methanol poisoning or vitamin B deficient anemias.
• Magnesium (antidote): Magnesium is used as an antidote to digitalis toxicity, hypomagnesemia, or torsades de pointes, a heart rhythm disorder. Digitalis is a chemical found in plants such as foxgloves and is used to produce digoxin, a drug used to treat cardiac arrhythmia and congestive heart failure. Digitalis toxicity causes arrhythmia and magnesium stabilize the heartbeat impulse generation.
• Methylene blue: Methylene blue is used to treat methemoglobinemia acquired from exposure to certain chemicals or drugs. Methylene blue converts methemoglobin, a form of hemoglobin that doesn’t effectively transfer oxygen to the cells, into normal hemoglobin. Methylene blue is also used off-label to treat encephalopathy (brain disease) from neurotoxicity caused by ifosfamide, a chemotherapy drug.
• Protamine: Protamine is a drug used to prevent postoperative bleeding by reversing the anticoagulant effects of heparin, a drug administered during cardiovascular surgeries, dialysis, and treatment of ischemic strokes to prevent blood clotting. Protamine, which is alkaline, combines with acidic heparin and forms a complex, reversing the anticoagulant effects of both drugs.
• Pyridoxine (antidote): Pyridoxine is a form of vitamin B6, an essential nutrient that has multiple functions in the body. Pyridoxine is used to counter the side effects of certain drugs and prevent drug-induced nerve damage. In ethylene glycol poisoning, pyridoxine helps in shunting the breakdown of glycolic acid from toxic to its nontoxic metabolites.
• Raxibacumab: Raxibacumab is a human immunoglobulin G1-gamma (IgG1-gamma) monoclonal antibody used to treat inhalational anthrax, caused by Bacillus anthracis. Raxibacumab works as an antibody against the bacterium’s protective antigen, the protein component that activates the anthrax toxins.
• Sodium bicarbonate (antidote): Sodium bicarbonate, commonly known as baking soda, is an alkaline salt. Sodium bicarbonate is administered as an intravenous solution to treat metabolic acidosis, a condition of high acidity in body fluids. Dehydration, many diseases, and excess ingestion of certain drugs or alcohol can cause acidosis. Sodium bicarbonate increases the pH values of blood and urine.
• Uridine triacetate: Uridine triacetate is a manufactured form of a naturally occurring enzyme uridine monophosphate which is essential for DNA and RNA synthesis. Uridine triacetate is used to treat hereditary orotic aciduria, a disorder that impairs the body’s ability to synthesize adequate uridine, and to prevent cell damage and death caused by chemotherapy drugs fluorouracil and capecitabine.

Other antidotes may be administered through various routes including:

• Oral:
  • Tablets
  • Dissolvable tablets
  • Capsules
  • Liquids, suspensions, and syrups
• Nasogastric tube: A tube inserted through the nose to deliver medication or nutrition directly into the stomach.
• Injections:
  • Intravenous (IV) injections into the vein
  • Intravenous infusions
  • Intradermal into the skin
  • Subcutaneous (SC) into the tissue under the skin
• Topical application: Gel, or powder mixed with jelly applied on the skin

The FDA-approved uses of antidotes include:

• Acetylcysteine (antidote):
  • Acetaminophen overdose
  • Acute hepatic failure (Orphan designation)
• Activated charcoal:
  • Drug overdose
  • Poisoning
• Ethanol:
  • Methanol toxicity (Off-label)
  • Ethylene glycol poisoning (Off-label)
  • Venous and lymphatic malformations (Orphan designation)
• Obiltoxaximab:
  • Prevention of inhalation anthrax
  • Treatment of inhalation anthrax in combination with antibacterial drugs
• Anthrax immune globulin:
  • Treatment of anthrax exposure, in combination with antibacterial drugs
• Botulinum antitoxin, heptavalent:
  • Noninfant botulism caused by A, B, C, D, E, F, and G types of botulinum toxins
• Botulism immune globulin IV:
  • Infant botulism is caused by A and B botulinum toxins, in babies below one year of age.
• Calcium chloride:
  • Emergency treatment of hypocalcemia (low calcium in the blood)
  • Hypocalcemic tetany (intermittent muscle spasm) in children
  • Treatment of arrhythmias (irregular heartbeat) associated with hypocalcemia, hyperkalemia (high potassium in the blood), and hypermagnesemia (high magnesium in the  blood)
  • Hypermagnesemia
  • Calcium channel blocker overdose
  • Beta-blocker overdose, refractory to glucagon and vasopressor
  • Diagnosis of thyroid medullary cancer
• Calcium gluconate:
  • Calcium supplementation in people with hypocalcemia
  • Treatment of conditions arising from hypocalcemia, such as:
    • Hypocalcemic tetany
    • Hypoparathyroidism
• Off-label uses include:
  • Management of cardiac arrest only in the presence of hypocalcemia, hyperkalemia, and hypermagnesemia
  • Hydrofluoric acid burn on the skin (topically applied)
  • Calcium channel blocker overdose
  • Hyperkalemia
  • Hypermagnesemia
• Digoxin immune FAB (antidote):
  • Digoxin overdose with potentially life-threatening cardiac toxicity, from accidental or suicidal ingestion, or from chronic therapy
• Prussian blue:
  • Known or suspected internal contamination with radioactive cesium and/or radioactive or nonradioactive thallium to increase their rates of elimination
• Fomepizole:
  • Methanol and ethylene glycol poisoning
• Glucarpidase:
  • Methotrexate toxicity in patients with delayed methotrexate clearance due to impaired renal function
• Hyaluronidase:
  • Extravasation
  • Skin test for hypersensitivity reaction
  • Hypodermoclysis (subcutaneous fluid infusion for hydration)
  • Urography (test to evaluate the urinary tract function), to improve the resorption of radiopaque agents
• Idarucizumab:
  • Dabigatran reversal in patients treated with dabigatran when reversal of anticoagulation effects are needed for emergency surgery or in the event of uncontrolled or life-threatening bleeding
• Potassium iodide:
  • During environmental radiation, emergency to prevent the thyroid gland from absorbing radioactive iodine and reduce the risk of thyroid cancer
  • Graves’ disease (hyperthyroidism) and thyrotoxic crisis
  • Preoperative preparation for thyroidectomy
  • As an expectorant to increase respiratory secretions
• Ipecac syrup:
  • Overdose/poisoning (discontinued)
• Leucovorin:
  • Methotrexate overdose
  • High-dose methotrexate rescue
  • Megaloblastic anemia due to folate deficiency
  • Adjunct to chemotherapy drug 5-fluorouracil (5FU) for advanced colorectal cancer treatment 
  • Methanol poisoning
  • Trimethoprim toxicity
• Levoleucovorin:
  • Rescue after high-dose methotrexate in osteosarcoma
  • Overdose or impaired elimination of folic acid antagonists
  • Adjunct to chemotherapy drug 5-fluorouracil (5FU) for metastatic colorectal cancer treatment
• Magnesium (antidote):
  • Digitalis toxicity in adults
  • Hydrofluoric acid burns in adults
  • Hypomagnesemia (low magnesium) in children
  • Torsades de pointes, a type of ventricular tachycardia (rapid heartbeat) in children
• Methylene blue:
  • Acquired methemoglobinemia (high blood level of methemoglobin, a form of hemoglobin that does not release oxygen to the cells)
  • Ifosfamide-induced encephalopathy, a brain disease caused by chemotherapy (off-label)
• Protamine:
  • Neutralization of unfractionated heparin, an anticoagulant drug used during cardiovascular procedures and dialysis
  • Reversal of overdose of low molecular weight heparin group of drugs dalteparin, tinzaparin, and enoxaparin (off-label)
• Pyridoxine (antidote): 
  • Isoniazid (an antibiotic used for tuberculosis treatment) overdose
  • Prevention of drug-induced neuritis (nerve inflammation)
  • Ethylene glycol toxicity
  • Gyromitrin (toxin present in Gyromitra species of fungi) poisoning
• Raxibacumab:
  • Treatment of inhalation anthrax in combination with appropriate antibacterial drugs
  • Prevention of inhalation anthrax when alternative therapies are not available or not appropriate
• Sodium bicarbonate (antidote):
  • Metabolic acidosis due to any reason
  • Cocaine toxicity
  • Cyanide toxicity
  • Salicylate toxicity
  • Barbiturate toxicity
  • Methyl alcohol intoxication
  • Tricyclic antidepressant toxicity
  • Cardiac arrest
• Uridine triacetate:
  • Hereditary orotic aciduria (a rare genetic metabolic disorder that causes megaloblastic anemia, neurological and developmental problems due to impaired functioning of uridine enzyme)  
  • Fluorouracil or capecitabine (chemotherapy drugs) overdose

Side effects of other antidotes vary with each type of drug. A few of the most common side effects may include:

• Acetylcysteine (antidote):
  • Nausea and vomiting
  • Fever and chills
  • Urticaria (hives) and pruritus (itching)
  • Pharyngitis (throat inflammation)
  • Anaphylactoid (anaphylaxis-like severe allergic) reactions
• Activated charcoal:
  • Constipation
  • Black stool
  • Slowing and blocking of the intestinal tract
  • Regurgitation into the lungs
  • Dehydration
• Ethanol:
  • Intoxication and agitation
  • Flushing and hypotension (low blood pressure)
  • Nausea and vomiting
  • Polyuria (excessive urination)
  • Hypoglycemia (low blood glucose level)
• Obiltoxaximab:
  • Hypersensitivity and anaphylaxis
  • Upper respiratory tract infections
  • Cough and nasal congestion
  • Urticaria and pruritus
  • Infusion site pain, swelling, and bruise
• Anthrax immune globulin:
  • Headache
  • Nausea
  • Infusion site pain and swelling
  • Back pain
  • Botulinum antitoxin, heptavalent:
  • Headache, fever, and chills
  • Nausea
  • Urticaria and pruritus
  • Hypersensitivity
  • Infusion reactions
• Botulism immune globulin IV:
  • Transient increase or decrease in blood pressure
  • Fever or drop in body temperature
  • Cardiac murmur
  • Skin reactions
  • Gastrointestinal effects
  • Respiratory tract issues
• Calcium chloride:
  • Hypomagnesemia (low magnesium in the blood)
  • Hypophosphatemia (low phosphorus in the blood)
  • Hypotension and vasodilation
  • Hypercalcemia
  • Tissue necrosis (death) at the injection site
  • Nausea and weakness
• Calcium gluconate:
  • Bradycardia (slow heartbeat)
  • Hypomagnesemia/hypophosphatemia
  • Hypotension
  • Headache
  • Constipation or diarrhea
  • Nausea and vomiting
• Digoxin immune FAB (antidote):
  • Exacerbation of heart failure and postural hypotension
  • Rapid ventricular response in patients with atrial fibrillation
  • Hypokalemia (low potassium level in the blood)
  • Allergic reactions and serum sickness
  • Phlebitis (inflammation of a vein)
• Prussian blue:
  • Constipation
  • Asymptomatic hypokalemia
• Fomepizole:
  • Headache
  • Nausea
  • Bad/metallic taste
  • Dizziness
  • Drowsiness
• Glucarpidase:
  • Paresthesias (abnormal skin sensations)
  • Flushing
  • Nausea and vomiting
  • Headache
  • Hypotension
  • Hyaluronidase:
  • Injection site reactions
  • Edema
  • Angioedema (swelling in the tissue under the skin or mucous membranes)
  • Urticaria (hives)
  • Allergic reactions
• Idarucizumab:
  • Hypokalemia
  • Delirium
  • Constipation
  • Pyrexia (fever)
  • Pneumonia
  • Headache
• Potassium iodide:
  • Arrhythmia (irregular heart rhythm)
  • Gastrointestinal irritation and bleeding, diarrhea
  • Goiter and swelling of neck/throat
  • Hyperthyroidism or hypothyroidism
  • Allergic reactions
• Ipecac syrup:
  • Prolonged vomiting and associated complications
• Leucovorin:
  • Nausea and vomiting
  • Diarrhea
  • Stomatitis (inflammation of the oral mucous membranes)
  • Thrombocytosis (excessive platelets in the blood)
  • Wheezing
  • Urticaria (hives) and anaphylactoid reactions
• Levoleucovorin:
  • Stomatitis
  • Diarrhea
  • Nausea and vomiting
  • Weakness, malaise, and fatigue
  • Dermatitis and alopecia (hair loss)
  • Decrease in or loss of appetite
• Magnesium (antidote):
  • Flushing
  • Hypotension
  • Hypothermia (drop in body temperature)
  • Central nervous system depression
  • Motor and respiratory paralysis
  • Heart block and abnormal ECG
• Methylene blue:
  • Pain in extremities
  • Chromaturia (abnormal urine color) and skin discoloration
  • Dysgeusia (taste disorder) and nausea
  • Feeling hot
  • Dizziness
  • Hyperhidrosis (excessive sweating)
• Protamine:
  • Anaphylaxis (severe allergic reaction)
  • Hypotension
  • Nausea and vomiting
  • Uncontrollable bleeding
  • Circulatory collapse
  • Pulmonary hypertension and edema
• Pyridoxine (antidote):
  • Ataxia (impairment of balance, coordination, and speech)
  • Headache
  • Somnolence (drowsiness)
  • Neuropathy (nerve damage)
  • Seizures
  • Increase in liver enzyme AST
• Raxibacumab:
  • Rash
  • Pruritus
  • Pain in extremities
  • Somnolence
  • Sodium bicarbonate (antidote):
  • Tetany (muscle spasms, cramps, or tremors)
  • Hypernatremia (high sodium level in the blood)
  • Alkalosis (excess alkalinity of blood)
  • Hypocalcemia (low calcium in the blood)
  • Gastric distension
  • Pulmonary edema
• Uridine triacetate:
  • Vomiting
  • Nausea
  • Diarrhea

Information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of some of the other antidotes include:

• Acetadote
• acetylcysteine (Antidote)
• Actidose-Aqua
• activated charcoal
• alcohol (ethyl)
• Amphadase
• Anthim
• Anthrasil
• anthrax antitoxin
• anthrax immune globulin
• Antizol
• BabyBIG
• botulinum antitoxin, heptavalent
• botulism immune globulin iv
• CaCl or CaCl(2)
• calcium chloride
• calcium gluconate
• Cetylev
• charcoal (activated)
• CharcoalAid
• Digibind
• DigiFab
• digoxin immune FAB (Antidote)
• ethanol
• ferric hexacyanoferrate
• fomepizole
• Fusilev
• glucarpidase
• Gluconate, Ca
• HBAT
• hyaluronidase
• Hylenex Recombinant
• idarucizumab
• Insta-Char
• iosat
• ipecac syrup
• Khapzory
• leucovorin
• levoleucovorin
• Liqui-Char
• magnesium (Antidote)
• methylene blue
• N-acetylcysteine (Antidote)
• obiltoxaximab
• Pima Syrup
• potassium iodide
• Praxbind
• protamine
• Provayblue
• Prussian blue
• pyridoxine (Antidote)
• Radiogardase
• raxibacumab
• sodium bicarbonate (Antidote)
• SSKI
• Superchar
• ThyroSafe
• ThyroShield
• uridine triacetate
• Vistogard
• vitamin B6 (Antidote)
• Vitrase
• Voraxaze
• Xuriden