FDA withdraws approval of long-discontinued MYSOLINE suspension
Oct 4, 2026 edition · GC-2026-0164 · Published 2026-10-04 · Version 2 · Withdrawn
FDA withdraws approval of the specific MYSOLINE 250 mg/5 mL suspension NDA effective September 29. The notice follows a long discontinuation and microbial-contamination concerns, with the holder agreeing to withdrawal; it does not withdraw every primidone formulation.
What happened
FDA’s September 29 notice withdraws approval of NDA 010401 for FHTA’s MYSOLINE primidone suspension, 250 mg/5 mL, effective that day. The holder agreed and waived a hearing. The suspension had been discontinued in 2001 after antimicrobial-effectiveness testing raised concern about potential microbial contamination, particularly Pseudomonas aeruginosa. In January 2026 FDA had already determined that this suspension was withdrawn from sale for safety or effectiveness reasons.
The notice recounts FDA’s view that reintroduction would require reformulation, appropriate preservative criteria correlated with antimicrobial testing, and demonstration of the revised product’s safety and effectiveness. FDA asked the holder about reformulation or agreed withdrawal in June, and the holder chose withdrawal without a hearing. Distribution of the specified suspension in interstate commerce without an approved application is unlawful. This is a product-and-application-specific approval action, not an announcement of a new recall of all primidone products or a conclusion about every formulation.
Scope and timing
- Authority status
- Withdrawn
- Applicability
- Operationally relevant
- Audience
- Health systems, Provider networks
- Jurisdiction
- Federal
Why it matters
Formulary and medication-master entries should identify the affected suspension and NDA precisely. A class-wide interpretation could prompt inappropriate changes to unrelated products and obscure the actual long-discontinued formulation.
Recommended action
Check references to the 250 mg/5 mL MYSOLINE suspension and NDA 010401 in product and formulary data. Verify any apparent use or procurement against the specific approval status and keep other primidone formulations separate.
Sources
- FHTA LLC; Withdrawal of Approval of New Drug Application for MYSOLINE (Primidone) Suspension, 250 Milligrams/5 MillilitersOfficial · Health and Human Services Department, Food and Drug Administration · 2026-09-29 · Source review 2026-10-05
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