First report on the pharmacokinetics of tramadol and O-desmethyltramadol in exhaled breath compared to plasma and oral fluid after a single oral dose.

Exhaled breath (EB) is a promising matrix for bioanalysis of non-volatiles and has been routinely implemented for drugs of abuse analysis. Nothing is known regarding the pharmacokinetics of therapeutics and their metabolites in EB. Therefore, we used tramadol as a model drug.