Primidone chemical structure

A number of compounds bearing different miscellaneous basic chemical structures have been found to possess significant anticonvulsant properties. A few such compounds are dealt with in this section, namely Primidione, Phenacemide, Carbamazepine, Sultiame, Valproic acid, Clonazepam. A. Primidone INN, BAN, USAN,... 

Special mention must be accorded to iatrogenic effects, where the usefulness of novel synthetic drugs is impaired by untoward side effects of obscure etiology. In some, if not many of them, these side effects may find their explanation in the inhibitory action of the drug upon a vitamin, as in the case of primidone vs. folic acid (B3a). These relationships appear to be fortuitous until the structural chemical kinship of drug and vitamin is recognized. 

Primidone is chemically and structurally similar to phenobarbital with the exception that the carbonyl group on Cj is replaced by a methylene group. This modification leads to the production of a drug with strong anticonvulsant properties without expressed soporific effects. 

The useful antiepileptic agents belong to several chemical classes. Most of the drugs introduced before 1965 are closely related in structure to phenobarbital, the oldest member of this therapeutic class. These include the hydantoins, phenytoin, mephenytoin, and ethotoin the deoxybarbiturate, primidone the oxazolidine-diones, trimethadione, and paramethadione and the succinimides, ethosuximide, methsuximide, and phensuximide. The agents introduced after 1965 include the benzodiazepines clonazepan and clorazepate, an iminostilbene, carbamazepine, and a branched-chain carboxylic acid, valproic acid. 

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