SPL Set ID: af593171-dabb-4ea3-b44c-89ed457b2c46

Chemical name: 5-ethyldihydro-5-phenyl-4,6 (1H, 5H)-pyrimidinedione. Structural formula: MYSOLINE (primidone) is a white, crystalline, highly stable substance, M.P. 279-284°C. It is poorly soluble in water (60 mg per 100 mL at 37°C) and in most organic solvents. It possesses no acidic properties, in contrast to its barbiturate analog. MYSOLINE 50 mg and 250 mg tablets contain the following inactive ingredients: lactose monohydrate, NF; magnesium stearate, NF; methylcellulose, USP; microcrystalline cellulose, NF; purified water, USP; sodium lauryl sulfate, NF; sodium starch glycolate, NF; and talc, USP. MYSOLINE 250 mg tablets also contain ferric oxide yellow, NF. _______________________________________________________________________________ ACTIONS MYSOLINE raises electro- or chemoshock seizure thresholds or alters seizure patterns in experimental animals. The mechanism(s) of primidone’s antiepileptic action is not known. Primidone per se has anticonvulsant activity as do its two metabolites, phenobarbital and phenylethylmalonamide (PEMA). In addition to its anticonvulsant activity, PEMA potentiates the anticonvulsant activity of phenobarbital in experimental animals. Chemical Structure