http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0000666/
Amitriptyline is used to treat symptoms of depression. Amitriptyline is in a class of medications called tricyclic antidepressants
Amitriptyline is also used to treat eating disorders, post-herpetic neuralgia (the burning, stabbing pains, or aches that may last for months or years after a shingles infection), and to prevent migraine headaches Amitriptyline (Brand names: Elavil, Endep, Vanatrip)
What is Amitriptyline?
Amitriptyline is a tricyclic antidepressant. It’s used to treat certain behavioral problems, such as separation anxiety, fear of noises, and anxiety in dogs, and urinating out of the litter box, spraying, and anxiety in cats. Amitriptyline requires a prescription from your veterinarian. For:
Cats and Dogs
http://www.1800petmeds.com/Amitriptyline-prod10480.html
http://www.horsesring.com/forums/showthread.php?12009-Fainting-Foals-Sleepy-Horses
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What Is Narcolepsy?
Narcolepsy in horses is characterized by excessive daytime sleepiness and episodes of cataplexy--the sudden but usually brief loss of muscle tone that results in partial or complete collapse.
As in humans, true
narcolepsy in horses is characterized by deep sleep or REM (rapid eye movement) sleep that occurs at an unusual time. Horses get most of their sleep on their feet, thanks to a unique physical structure known as the stay apparatus. This system of tendons and ligaments in the hind legs, and to a lesser degree the front legs, locks the limbs in extension, allowing the horse to sleep while he is standing. Even with this ability, horses typically lie down at least once a day to achieve deep sleep. Normal horses that are provided with comfortable, familiar surroundings can obtain sufficient REM sleep during short periods of recumbency.
Treatment?
Once a definitive diagnosis is made, several treatment options are available. Although imipramine--a tricyclic antidepressant widely used in human medicine--is the standard treatment for narcolepsy in horses,
another tricyclic antidepressant that can be used is amitriptyline. Tricyclic antidepressants work to block the re-uptake of serotonin and norephinephrine. Nick Dodman, BVMS, Dipl. ACVA, ACVB, a professor, section head, and program director in the Animal Behavior Department of Clinical Sciences at Tufts Cummings School of Veterinary Medicine in North Grafton, Mass., believes "it is this catecholamine surge (the block of serotonin and norephinephrine) that buoys the level of consciousness/awareness and prevents the horse literally from falling asleep on his feet." According to Dodman, amitriptyline is slightly more potent than imipramine, so when horses are first introduced to the drug, they should be on colic watch to see how they react to it. Dodman says that he has used amitriptyline 100% successfully on one narcoleptic horse at 300 mg once daily given in a mixture of sweet feed and molasses. "The horse ate it as willing as an aperitif (appetizer)," says Dodman.
