Selegiline

MAO-B inhibitor for PPID in horses (historical use); canine cognitive dysfunction syndrome. Selective MAO-B inhibitor (L-deprenyl/selegiline HCl). Mechanism: irreversibly inhibits monoamine oxidase type B (MAO-B) → reduces dopamine catabolism → increases CNS dopaminergic activity. In horses (PPID): enhances dopamine-mediated inhibition of the pars intermedia → reduces ACTH hypersecretion. In dogs (CDS): neuroprotective via increased dopamine, reduced reactive oxygen species. Key information MAO-B inhibitor. Used for canine cognitive dysfunction and equine PPID. Drug interactions: do NOT combine with SSRIs, tricyclics, opioids (serotonin syndrome), or tyramine-rich foods. Store at room temperature.

Oral tablets: Administer orally. May be given with food to improve compliance and reduce GI upset. Administer on an empty stomach for optimal absorption. (best absorption) or with a small amount of food. Administer once daily in the morning. Store at room temperature; protect from light. If a dose is missed Give the missed dose as soon as you remember. If the next dose is due within a few hours, skip the missed dose and resume the regular schedule. Never give a double dose.

GI: vomiting, diarrhea, anorexia (most common). CNS: restlessness, disorientation, repetitive behaviors (high doses). Serotonin syndrome with serotonergic drugs (TCAs, SSRIs — contraindicated combinations). Salivation. Pruritus. Horses: excitability reported.

For animals Horses: for PPID — monitor ACTH levels and clinical signs (hair coat, laminitis, PU/PD). Dogs: cognitive dysfunction — allow 4–8 weeks for effect. Drug interaction: CONTRAINDICATED with SSRIs, TCAs, tramadol, meperidine (serotonin syndrome/hypertensive crisis). 14-day washout from selegiline before starting serotonergic drugs. Not approved for use in food-producing animals. For people handling this medication Wash hands thoroughly with soap and water after handling. Avoid contact with eyes; if contact occurs, flush with water for 15 minutes and seek medical attention. Keep out of reach of children. If accidental ingestion occurs, contact Poison Control (1-800-222-1222). MAO-B inhibitor — Wash hands thoroughly with soap and water after handling. after handling. Serious serotonin syndrome and hypertensive crisis possible if accidental human ingestion occurs with concurrent serotonergic or tyramine-rich foods. Keep out of reach of children.

Contact your veterinarian immediately. Selegiline overdose causes serotonin syndrome-like signs: agitation, tremors, hyperthermia. Dangerous with concurrent serotonergic drugs. Contact your veterinarian, a veterinary emergency clinic, or the ASPCA Animal Poison Control Center (888-426-4435) immediately. Do not induce vomiting unless specifically directed by a veterinary professional.