Poisoning in Which Plasma Levels Should Be Measured. NB: Always Check the Units of Measurement Used by Your Laboratory
| Poison | Plasma level at which specific treatment is indicated | Treatment |
|---|---|---|
| Aspirin and other salicylates | 250–500 mg/L (mild poisoning) 500–750 mg/L (moderate poisoning) 750–1000 mg/L (severe poisoning) >1000 mg/L (massive poisoning) | Fluids Urinary alkalinization HD HD |
| Digoxin | >4ng/mL | Digoxin-specific antibody fragments |
| Ethylene glycol | >500 mg/L | Ethanol or 4-methyl pyrazole, HD |
| Iron* | >3.5 mg/L | Desferrioxamine |
| Lithium (send sample in plain tube) | >5 mmol/L | HD |
| Methanol | >500 mg/L | Ethanol or 4-methyl pyrazole, HD |
| Paracetamol | See Appendix 36.1 | Acetylcysteine |
| Theophylline | >50 mg/L | RAC, HD |
| Carbamazepine | >40 mg/L (170micromol/L) | MDAC, consider lipid emulsion for cardiac toxicity |
HD, haemodialysis; RAC, repeated oral activated charcoal.
* Also measure plasma iron level if clinical evidence of severe iron toxicity (hypotension, nausea, vomiting, diarrhoea) or after massive ingestion (>20 mg elemental iron/kg body weight; one 20 mg tablet of ferrous sulphate contains 6 mg elemental iron).