After the introduction of phenytoin, search for antiepileptic drugs with a structure similar to that of phenobarbital and phenytoin continued, and primidone was synthesized in 1949 (Bogue and Carrington 1953). It was introduced into clinical use in 1952 and found to be effective for the control of complex partial and secondarily generalized seizures (Handley and Stewart 1952). There has been some controversy as to whether it is a distinct antiepileptic drug or simply a prodrug of phenobarbital. Most investigations now suggest that primidone has pharmacodynamic properties distinct from those of phenobarbital. The manufacturer of primidone has announced the discontinuation of this drug. Primidone was withdrawn from the market in the Netherlands in 2004 but was available for some time on a limited basis (de Haan et al 2003). In the United Kingdom, the drug will be available until an alternative source of manufacture is found.