Domperidone

Dopamine antagonist/prokinetic for equine grass sickness (dysautonomia) and agalactia in fescue-exposed mares; enhances GI motility and prolactin release. Dopamine D2 receptor antagonist/prokinetic agent. Mechanism: blocks D2 receptors in the GI tract (promotes gastric emptying and intestinal motility) and in the pituitary lactotrophs (disinhibits prolactin release → stimulates milk production). Poor CNS penetration (P-gp substrate) reduces extrapyramidal effects. Used in horses for agalactia and grass sickness. Key information Dopamine antagonist — prokinetic. Used for fescue toxicosis/agalactia in mares. Store at room temperature. May cause galactorrhea. Does not cross blood-brain barrier.

Oral solution or compounded preparation (horses): Administer orally via dose syringe placed at the back of the tongue, or mix into a small amount of palatable feed. — dose via syringe. Oral tablets (dogs, extra-label): Administer orally. May be given with food to improve compliance and reduce GI upset. Administer with food to reduce GI adverse effects. Administer at consistent time each day. Store at room temperature; protect from light. If a dose is missed Administer as soon as you remember. If it is almost time for the next scheduled dose, skip the missed dose and resume the normal schedule. Never double up doses to make up for a missed one.

GI: increased GI motility, diarrhea. CNS: restlessness, agitation (D2 antagonism). Prolonged QT interval (rare — cardiac risk). Galactorrhea/mammary development (intended in mares for agalactia). Headache equivalent. Horses: generally well tolerated at labeled doses.

For animals Not for use in animals with GI obstruction. Drug interaction: QT-prolonging drugs — avoid concurrent use. Horses: for agalactia treatment — monitor for adequate milk production. Use with caution in pregnant animals. — may stimulate parturition if used near term in some species. 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). Dopamine antagonist — Wash hands thoroughly with soap and water after handling. after handling. Hormonal effects (prolactin elevation) with chronic human exposure. Keep out of reach of children. Pregnant women and women of childbearing age should avoid contact.

Contact your veterinarian. Domperidone overdose may cause galactorrhea and mild neurological signs.