At present, it remains however unclear to what extent the evidence concerning resuscitation of the poisoned patient with lipid emulsion may reflect publication bias. To our knowledge, only one controlled human trial has been conducted at present. In a randomized crossover study, Litonius et al. investigated the effects of lipid emulsion on plasma concentrations of bupivacaine in eight healthy subjects. It was found that lipid emulsion lowered the total plasma concentrations of bupivacaine. This was attributed to an altered distribution and contradicted so the above hypothesis of a lipid sink-mechanism as the fraction of non-lipid bound bupivacaine was unchanged. The mechanism by which lipid emulsion may attenuate the effects of cardio toxic xenobiotics must therefore still be regarded as undecided. This lack of evidence calls for further human studies in order to elucidate the pharmacokinetic and pharmacodynamic consequences of intravenous lipid emulsion. The purpose of this double blind, randomized placebo-controlled crossover clinical trial is to investigate the effects of intravenous lipid emulsion on the pharmacokinetic and pharmacodynamic properties of the adrenoceptor antagonist metoprolol in a human model of beta blocker overdose.