A high performance liquid chromatographic assay for tocainide with alternate application for the determination of lidocaine, procainamide, and N-acetylprocainamide.

We describe a simple, isocratic high-performance liquid chromatographic method for measuring the oral antiarrhythmic agent tocainide in serum. The extraction requires 200 microliters of serum, is performed on a reverse-phase column, and utilizes the drug mepivacaine as the internal standard. This analytical method can also be used to assay procainamide, n-acetylprocainamide, or lidocaine with minor modifications to either the extraction protocol or the wavelength used to monitor column eluant.