Tardoxal

**Tardoxal** is a naturally occurring small molecule formulation of pyridoxal 5'-phosphate, the active form of vitamin B6, developed by Medicure Inc. for the treatment of tardive dyskinesia (TD), a movement disorder induced by long-term antipsychotic use. It acts as a **purinergic P2 receptor antagonist**, potentially reducing involuntary movements such as grimacing, tongue protrusion, and lip smacking by modulating neuroleptic-induced extrapyramidal symptoms. Medicure conducted a Phase IIa TEND-TD trial (NCT00917293) showing a non-significant trend toward improvement in Abnormal Involuntary Movement Scale (AIMS) scores, with nausea as a noted side effect; the program received FDA Fast Track designation but remains experimental and unapproved, with development paused or reformulated to address tolerability.[1][2][3][9][10][14]

Brand names

Tardoxal

Other names

Pyridoxal 5'-phosphatePyridoxal phosphateP5PP-5PP 5PMC-1MC1MC 1TARDOXAL