Botulinum toxin (BoNT) has now been used for more than 20 years with remarkable success to treat various conditions caused by hyperactivity of muscles or exocrine glands (Scott, 1980; Moore & Naumann, 2003). Its use for treatment of pain syndromes is currently being explored. For most of its indications BoNT therapy is the therapy of choice. For some it has revolutionized therapy altogether. This, together with its exploding use in cosmetics, has generated an industry with annual sales in excess of one billion US dollars. However, 20 years into this therapy, we are still using more or less the original BoNT drugs.

As shown in Figure 24.1 the first BoNT drug was registered in 1989 as Oculinum®. In 1992 its name was changed to Botox®. In 1999 a modified formulation of Botox was marketed without a name change. In 1991 Dysport® was registered as another BoNT type A drug and in 2000 NeuroBloc®/Myobloc® became available as the first – and so far only – BoNT type B drug. When NeuroBloc/Myobloc was introduced to the neurological community it soon became apparent that it has a much stronger affinity to autonomic synapses than to motor synapses as compared to BoNT type A drugs (Dressler & Benecke, 2003) thus producing frequent autonomic side effects in the treatment of motor disorders. This, together with its high antigenicity (Dressler & Bigalke, 2004), has prevented its large-scale use. In 2005 Xeomin® was marketed in Germany.