Hyperosmolar sodium bicarbonate solutions are widely used in clinical toxicology both as an antidote to drugs that impair fast sodium channel function and as an alkalinising agent to manipulate drug distribution and excretion (salicylate and phenobarbitone). It is also used in profound metabolic acidosis with cyanide, isoniazid and toxic alcohol toxicity.
Intravenous pyridoxine is used in high doses to control the metabolic acidosis and seizures associated with isoniazid overdose and poisoning from other hydrazine compounds (Gyromitra mushrooms and jet/rocket fuel). It is also used as a adjunct to ethylene glycol toxicity
Pralidoxime reactivates acetylcholinesterase only if irreversible binding to the OP has not already occurred ("ageing"). The acetylcholinesterase enzyme has two parts to it. In organophosphate poisoning, an organophosphate binds to just one end of the acetylcholinesterase enzyme (the esteric site), blocking its activity.
A reversible acetylcholinesterase inhibitor useful in the treatment of central anticholinergic delirium that is not easily controlled by benzodiazepine sedation and there is high risk for aspiration and excessive sedation. Only for those patients who have an isolated anticholinergic agent toxicity (not the polypharmacy overdose).
Potent oral chelating agent for a broad range of heavy metals. Agent of choice in very few scenarios due to poor side-effect profile and the existence of better tolerated and more efficacious agents. If possible EDTA or Succimer should be used instead.
Long-acting synthetic octapeptide analogue of somatostatin useful in the control of sulfonylurea-induced hypoglycaemia (BSL <4 mol/L) either from overdose or an iatrogenic source. It is also useful in hypoglycaemia induced from Quinine.
This opioid antagonist is a useful adjunct in the management of opioid intoxication, particularly if there is CNS or respiratory depression. Caution is advised in those who are opiate-dependant and naloxone should only be used if there is significant CNS (GCS <12) and respiratory depression (RR <8).
N-acetylcysteine (NAC) is the most widely used sulfhydryl donor in the treatment of paracetamol poisoning. Standard therapy consists of a series of three infusions given over 20 hours.
Methylene Blue is the treatment of choice for symptomatic drug-induced methaemoglobinaemia (signs of hypoxia with chest pain, dyspnoea or confusion) or consider in asymptomatic patients with methaemoglobin (MetHb) levels >20%.
Intravenous lipid emulsion (IVLE) is a sterile emulsion of soyabean oil in water, used in parenteral nutrition. It is a novel antidote which requires further study but may have a role to play in the resuscitation of patients with refractory cardiac arrest induced by local anaesthetics that are resistant to standard protocols.
Funtabulously Frivolous Friday Five 157 - Just when you thought your brain could unwind on a Friday, some medical trivia FFFF.
Short editorial comments on articles from Vol. 24 Issue 2 of Emergency Medicine Australasia (EMA Journal) published online in April 2012.