Drug Monitoring

A paracetamol concentration should be done in all unconscious poisonings. Its presence increases the likelihood of ingestion of codeine or dextropropoxyphene.

Blood concentrations are generally unhelpful but should be done if there is suspicion of ingestion of lithium or anticonvulsants (carbamazepine, phenytoin, valproate).

A normal plasma cholinesterase excludes significant organophosphate poisoning but may be normal in carbamate poisoning.