Xylocain (lidocaine, lignocaine), its discovery and Gordh's contribution to its clinical use.

Hans v. Euler, while investigating how genes and enzymes were chemically related in some chlorofylldefective mutants of barley, isolated gramine, an indole. Erdtman synthetized isogramine and found it to have weak anesthetic properties. He then together with Löfgren synthetized other amino-amides, but no one of them could compete with the existing local anesthetics of the ester-type, derivatives of para-aminobenzoic acid, e.g. procaine. Later Löfgren and Lundqvist followed up these studies and found an amid compound lidocaine (2-dimethylaminoacet-2, 6-xylidide). Lidocaine represented such a significant advance over procaine in clinical tests preformed by T. Gordh that it was introduced for clinical use. It has now during a half century been the standard local anesthetic drug. All local anesthetics are neurotoxic in high enough doses. Xylocain, however, has had an excellent record of safety. Only during the last years have there been reports on possible toxic irritation and damage by Xylocain used for spinal anesthesia. The aetiology is still not clear In this connection two early observations by Gordh and his coworkers are discussed.