The antidote for acetaminophen is acetylcysteine. Acetylcysteine is administered intravenously and is usually more effective if given within 8 - 10 hours from the time of ingestion. Mucomyst is the oral preparation of acetylcysteine that is administered orally. Incidentally, Mucomyst can be used as a mucolytic expectorant to help with the clearance of thick mucus secretions.
Atropine is used as the antidote for anticholinesterase or organophosphate poisoning. It is usually administered intravenously with an initial dose of 1-2 mg in adults with subsequent doubling of the dose every 15 minutes if there is no response. Atropine can also be used for rapid onset mushroom poisoning especially when there is a predominance of muscarinic excess symptoms such as bradycardia, hypotension, rhinorrhea, bronchospasm, respiratory distress, hypersalivation, abdominal cramping, and diarrhea.
In the case of tricyclic antidepressants and other membrane depressant cardiotoxic drugs, bicarbonate sodium is the antidote of choice. The dose is usually 1-2 mEq/kg administered intravenously. Cautious use is advised for patients with heart failure. In addition, clinicians should closely monitor these patients for signs of sodium overload.
The antidote for calcium channel blockers is calcium administered in large doses. The initial dose is usually 15 mg/kg intravenously.
The antidote for digoxin is digoxin specific antibodies. Each vial of digoxin antibodies binds approximately 0.5 mg of digoxin. Digoxin antibodies are usually indicated in patients with arrhythmias and hyperkalemia.
Deferoxamine is used in cases of intoxication with iron salts. 100 mg of deferoxamine administered intravenously binds 8.5 mg of iron.
An overdose of caffeine and theophylline is usually treated with Esmolol. Esmolol is a short acting beta blocker, and the dose for administration is 25 - 50 mcg/kg/min intravenously.
Methanol and ethylene glycol intoxication are usually treated with ethanol administration. Fomepizole is also an antidote to methanol and ethylene glycol intoxication and is much more convenient to use than ethanol. The dose for Fomepizole is 15 mg/kg and can be repeated every 12 hours.
Benzodiazepine overdose can be reversed with Flumazenil. In adults, the dose is 0.2 mg intravenously which can be repeated up to a maximum of 3 mg. Flumazenil should not be administered in patients with seizures, benzodiazepine dependence, or in cases of tricyclic overdose.
Cyanide poisoning is treated with hydroxocobalamin which converts cyanide to cyanocobalamin which is Vitamin B12. The dose of hydroxocobalamin is 5 g over 15 minutes intravenously.
Beta blocker overdose is managed by administering glucagon which reverses the beta blocker effects. 5 - 10 mg iv of glucagon is initial dose used to reverse the bradycardia and hypotension associated with beta blocker overdose.
Naloxone (Narcan) is used as the antagonists of opioid and other narcotics. Usually, 0.4 mg of naloxone is given initially and can be repeated up to a maximum of 2 mg. Naloxone can be administered intramuscularly, subcutaneously or intravenously. Larger doses may be necessary to reverse the effects of overdose from codeine, propoxyphene or fentanyl derivatives. It is also important to note that the duration of action for naloxone is usually 2 -3 hours while that of the intoxicant narcotic may be significantly longer.
Carbon monoxide poisoning can be either accidental or intentional. It is usually treated with 100% oxygen administered via a non-rebreather mask. Hyperbaric chambers can be used in cases of severe poisoning.
Physostigmine is used to treat the delirium associated with the anticholinergic drugs. Physostigmine can cause bradycardia and can increase bronchial secretions and even cause seizures. Do not use physostigmine in the case of tricyclic antidepressant overdose. In the case of physostigmine overdose, atropine can be used as an antidote.
Pralidoxime is also used to treat organophosphate and cholinesterase inhibitor overdose; although, the benefits in organophosphate overdose are not well established.