Mysoline

Controls grand mal, psychomotor, and focal epileptic seizures. NDA 9170, held by Valeant. Primidone.

As of Nov 13, 2026, NDA 9170 (Mysoline), held by Valeant, was first approved by FDA on Mar 8, 1954, with 19 approved supplements and 0 published complete response letters.

First approved: Mar 8, 1954
Review: Priority
Supplements approved: 19
Complete response letters: 0

What It's For

From the FDA-approved label (Indications and Usage)

INDICATIONS AND USAGE MYSOLINE, 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.

Full prescribing information on DailyMed ↗

Approvals and New Uses

The original application and every efficacy supplement, newest first; all 20 submissions below

Date	Submission	Status	Documents
Mar 8, 1954	Original applicationNew molecular entity · Priority review	Approved	None posted

Products

2 strengths and forms

Product	Active ingredient	Marketing
Mysoline250MG · tablet;oral	Primidone	RxReference drug
Mysoline50MG · tablet;oral	Primidone	RxReference drug

All 20 submissions, including labeling and manufacturing supplements

Date	Submission	Status	Documents
Jun 10, 2020	Supplement 40Manufacturing	Approved	Label Medication Guide Letter
Feb 19, 2016	Supplement 39Manufacturing · Priority review	Approved	None posted
Aug 10, 2011	Supplement 38REMS	Approved	Letter
Jul 21, 2010	Supplement 35Labeling · Standard review	Approved	Label Letter
May 8, 2009	Supplement 34Manufacturing	Approved	Label Letter
Apr 23, 2009	Supplement 36Labeling	Approved	Label Letter
Jan 29, 2009	Supplement 33Manufacturing · Priority review	Approved	Letter
Jun 13, 2008	Supplement 31Manufacturing	Approved	Letter
May 6, 2002	Supplement 21Manufacturing · Priority review	Approved	None posted
Dec 14, 2000	Supplement 20Manufacturing · Priority review	Approved	None posted
Apr 10, 2000	Supplement 19Labeling · Standard review	Approved	None posted
Mar 18, 1994	Supplement 18Manufacturing · Priority review	Approved	None posted
Oct 25, 1989	Supplement 17Manufacturing · Priority review	Approved	None posted
Aug 11, 1989	Supplement 13Manufacturing · Priority review	Approved	None posted
Jul 28, 1988	Supplement 16Manufacturing · Priority review	Approved	None posted
Sep 2, 1987	Supplement 14Manufacturing · Priority review	Approved	None posted
May 20, 1982	Supplement 12Manufacturing · Priority review	Approved	None posted
Jan 28, 1982	Supplement 11Manufacturing · Priority review	Approved	None posted
Feb 18, 1981	Supplement 7Manufacturing · Priority review	Approved	None posted
Mar 8, 1954	Original applicationNew molecular entity · Priority review	Approved	None posted

Identifiers

Application: NDA 9170
Drugs@FDA: Overview at FDA
Company: Valeant Pharmaceuticals

Approvals, supplements, products and documents come from FDA's Drugs@FDA data files, refreshed daily; Drugs@FDA lists approved applications only. Complete response letters are FDA's published letters. Drugs@FDA and FDA complete response letters