Routine methods in toxicology and therapeutic drug monitoring by high-performance liquid chromatography. IV. A rapid...

A fast, simple, and sensitive method for the simultaneous determination of total and free propranolol and its active metabolite 4-hydroxypropranolol in plasma by high performance liquid chromatography is described. Both propranolol and 4-hydroxypropranolol are detected by fluorescence at one wavelength detector setting. The limit of sensitivity of the method is 2 ng/ml for 4-hydroxypropranolol and 1 ng/ml for propranolol. The method is fast since it involves a single extraction step followed by evaporation of organic solvent and chromatography of the residue. The method takes only 10 min per sample and thus can be set up in a therapeutic drug-monitoring laboratory for monitoring propranolol levels routinely.