FOI release

1972 CSM Sub-Committee teratogenicity studies (phenytoin and sodium valproate)

This request was refused in part, so we didn't provide some of the information the requester asked for. This may include information where we can neither confirm nor deny that we hold it.

Case reference FOI2026/00181

Received 18 February 2026

Published 8 May 2026

Request

I am requesting access to original regulatory documents created, reviewed, or held by the MHRA or its predecessor bodies, including the Committee on Safety of Medicines (CSM), relating to teratogenicity studies conducted or assessed in 1972. Information requested 1. Rat study – sodium valproate vs phenytoin Please provide: • The complete 1972 paper/report produced by the CSM Sub-Committee on Toxicity and Clinical Trials concerning rat studies comparing sodium valproate and phenytoin, beginning at pages 0/1 and continuing in full, including: o All pages without omission o Tables, figures, appendices, and statistical analyses o Marginal notes, annotations, or internal commentary o Any accompanying covering papers, briefing notes, or submissions considered alongside the study 2. Rabbit teratogenicity study Please also provide: • The full rabbit teratogenicity study report referred to in the same regulatory context, including: o Complete methodology and results o Any comparative assessment involving sodium valproate and/or phenytoin o Any internal evaluations, conclusions, or regulatory commentary generated by or for the CSM or its sub-committees ________________________________________ Clarifications to prevent misinterpretation • This request is for primary source documents, not summaries, digests, or retrospective reviews. • The age of the documents (circa 1972) strongly suggests that: o Commercial confidentiality exemptions are unlikely to apply, and o Any remaining personal data concerns can be addressed via proportionate redaction. If redactions are applied, please: • Cite the specific FOIA exemption relied upon for each redaction, and • Provide the public interest test reasoning where applicable. Format and time limits

Response

See attached

Documents

• 22 June 1972 CSM minutes-final redacted.pdf (381.2 KB)
• FOI2026_00181 (redacted).pdf (1.2 MB)
• Rabbit, rat study-redacted final.pdf (9.3 MB)

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