Fluphenazine Decanoate

Long-acting phenothiazine tranquilizer for fear, anxiety, and stereotypic behaviors in horses. Long-acting phenothiazine antipsychotic (fluphenazine decanoate). Mechanism: dopamine D2 receptor antagonist; also blocks alpha-1 adrenergic and histamine H1 receptors → sedation and behavioral suppression. Decanoate ester provides 2–4 week duration of action after IM injection (depot formulation). Used in horses for long-term behavioral management. Key information Long-acting antipsychotic/phenothiazine. DEA: not scheduled. Use with extreme caution — prolonged sedation. Extrapyramidal side effects. Not reversed by yohimbine.

Injectable depot (decanoate): administer deep IM into large muscle mass. Horses: administer as single IM injection; effects last 2–4 weeks. Monitor closely for adverse effects — no reversal available for depot formulation. Store at room temperature; protect from light. If a dose is missed This medication is administered by a veterinarian or veterinary staff in a clinical setting. Missed doses are managed by your veterinary team — contact your veterinarian to reschedule.

Extrapyramidal reactions: dystonia, akathisia, tardive dyskinesia (prolonged use). Persistent penile prolapse (horses). Sedation. Hypotension (alpha-1 block). Long duration of action with depot formulation — difficult to manage adverse effects once injected.

For animals Horses: depot formulation — cannot be reversed; if adverse effects occur (persistent penile prolapse, severe neurological signs), supportive care only. Monitor for extrapyramidal effects. Not approved for use in food-producing animals. For people handling this medication Wear gloves when handling. Wash hands thoroughly with soap and water after handling. Phenothiazine — contact dermatitis with skin exposure. Avoid eye contact. Keep out of reach of children. Pregnant women and women of childbearing age should avoid contact. Long-acting depot — once administered to the animal, human exposure risk is minimal.

Contact your veterinarian immediately. Long-acting phenothiazine overdose causes prolonged deep sedation, cardiovascular depression, and extrapyramidal effects. Effects may last days to weeks. Supportive care required.