Primidonedrug info
primidone 125 MG Oral Tablet
What it is used for
Primidone, used alone or concomitantly with other anticonvulsants, is indicated in the control of grand mal, psychomotor, and focal epileptic seizures. It may control grand mal seizures refractory to other anticonvulsant therapy.
Text above is quoted in full from the FDA-approved drug label published by openFDA, effective January 13, 2026. Matched to this product by RxNorm code. Cross-references to other sections of the full prescribing information have been removed, since they point to a document not shown here. Nothing else is changed: no sentence is shortened, reworded or summarised.
Description
Chemical name: 5-ethyldihydro-5-phenyl-4,6 (1H, 5H)-pyrimidinedione.
Structural formula: 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. Primidone Tablets, USP 50 mg, 125 mg and 250 mg contain the following inactive ingredients: lactose monohydrate, NF; magnesium stearate, NF; hypromellose, USP; microcrystalline cellulose, NF; purified water, USP; sodium lauryl sulfate, NF; sodium starch glycolate, NF; and talc, USP/NF. _______________________________________________________________________________. Chemical Structure ACTIONS Primidone tablets 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.
Text above is quoted in full from the FDA-approved drug label published by openFDA, effective January 13, 2026. Matched to this product by RxNorm code. Cross-references to other sections of the full prescribing information have been removed, since they point to a document not shown here. Nothing else is changed: no sentence is shortened, reworded or summarised.
This page reproduces regulatory text for reference. It is not medical advice, and KenyRx is not a pharmacy or a prescriber. Talk to a doctor or pharmacist about whether a medicine is right for you.
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