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(for veterinary information only)
L-DEPRENYL HYDROCHLORIDE
SELEGILINE HYDROCHLORIDE
BRAND NAME: ANIPRYL OR ELDEPRYL
AVAILABLE IN
2 mg, 5 mg, 10 mg, 15 mg, 30 mg
TABLETS
sold in 30 tablet blister packs
HISTORY AND BACKGROUND
There are two uses for L-Deprenyl in the dog: the treatment of Cushing’s disease, an adrenal hormone imbalance, and the treatment of senile mental deterioration (“Canine Cognitive
Dysfunction.”). We will discuss the applications in the treatment of Cushing’s disease first as this is what L-Deprenyl was first approved for in the dog. If you wish to skip to more discussion on Canine
Cognitive Dysfunction click here.
CUSHING’S DISEASE
Cushing’s disease is the insidious debilitating hormone imbalance that results when the adrenal glands overproduce cortisone. Most cases (85%) occur as the result of a tumor in the pituitary
gland which produces a stimulatory hormone called “ACTH.” This hormone leads both adrenal glands to enlarge and overproduce cortisone which in turn leads to to symptoms associated with Cushing’s disease.
Treatment has traditionally centered on suppressing adrenal gland production and release of cortisone but this approach has been fraught with potential for side effects.
L-Deprenyl has allowed for a new approach by suppressing the pituitary gland directly.
Monoamine Oxidases are enzymes we have in two areas: the brain (monoamine oxidase inhibitor -B) and in the liver/GI tract (monoamine oxidase inhibitor-A). In the brain, these enzymes break down used
neurotransmitters (chemicals that enable nerves to communicate). One of these neurotransmitters is called “Dopamine” and one of its functions is the regulation, specifically the inhibition, of ACTH. By using a
Monoamine Oxidase-B inhibitor, dopamine is not broken down; it persists and provides extra inhibition of ACTH. L-Deprenyl further acts on the enzymes which produce dopamine so that more dopamine is produced.
L-Deprenyl is a monoamine oxidase inhibitor specific to the brain’s monoamine oxidases; those of the liver/GI tract are not affected. This effect on ACTH inhibition allows for the treatment of pituitary dependent Cushing’s disease in dogs as well as the treatment of Parkinson’s syndrome in humans.
An additional effect of L-Deprenyl stems from an interaction with brain enzymes that destroy free radicals.
By helping to rid the brain of destructive free radicals, L-Deprenyl has proven useful in treating Alzheimer’s disease in humans as well as “Canine Cognitive Dysfunction” (senility) in dogs. L-Deprenyl was approved in the dog first for the treatment of Cushing’s disease but has since been approved for the treatment of Canine Cognitive Dysfunction.
CANINE COGNITIVE DYSFUNCTION
Pet owners have long been frustrated by age related behavior problems involving loss of house-training, apparent memory loss or disorientation, sleep disturbances (either waking at the wrong time or
sleeping unusually deeply) and loss of interest in social activities with the family. Such behavior changes are often “written off” as being normal aging. A recent study at the University of California School
of Veterinary Medicine demonstrates how common these observations are: out of 69 dogs participating, 32% of 11 year old dogs were affected by this syndrome and that 100% of dogs 16 years of age older were
affected.
Still, the high frequency with which the syndrome is seen in older dogs does not make it
normal. Other studies have shown that dogs affected by this syndrome show deposition of a protein called “amyloid” in their brains in patterns very similar to the amyloid plaques found in the brains of humans with Alzheimer’s disease.
Cognitive dysfunction is associated with depletion of dopamine, the neurotransmitter mentioned above.
As described above, also, L-Deprenyl helps prolong dopamine activity which may account for part of its efficacy in treating Cognitive Dysfunction. Further, dopamine breakdown results in harmful biochemicals known as free radicals. The use of L-Deprenyl also helps reduce amounts of free radicals in the brain.
For Cushing’s Syndrome Information Site click here
For more information on Canine Cognitive Dysfunction, here is a link to Pfizer’s web site on the subject at www.anipryl.com
HOW THIS MEDICATION IS USED
There are two main uses of this medication: the treatment of pituitary dependent Cushing’s disease in the dog and the treatment of canine cognitive dysfunction (senility). In
treating Cushing’s disease, L-deprenyl is given once a day for two months. If no response is seen in this time, the dose is doubled for an additional month. If still no response is seen, another form of
treatment should be pursued. Approximately 80% of dogs with Cushing’s disease will respond to L-Deprenyl.
A lower dose of L-deprenyl is used in the treatment of canine cognitive dysfunction. Of the 69 dogs mentioned above, approximately 76% showed improvement on L-deprenyl after one month of
therapy. Some dogs improve in the first few days or weeks, some dogs did not show improvement until the second month. Often dogs would continue to improve during the first three months. If no improvement is seen
after the first month, the dose is doubled for an additional one month before re-evaluating the patient for an underlying medical problem that could be causing the behavor problems observed.
SIDE EFFECTS
Whereas with previous treatments for Cushing’s syndrome, monitoring tests to avoid side effects were central to treatment. The beauty of treatment of Cushing’s syndrome with L-Deprenyl is
that no monitoring tests are necessary. This is because adrenal function is not directly altered.
There is a 5% incidence of unacceptable side effects with L-Deprenyl treatment. These side effects include: vomiting, diarrhea, listlessness, disorientation, diminished hearing, or
restlessness.
When three times the recommended dose was used in dogs, salivation, weight loss, panting, dehydration, pacing, and poor pupil response to light were observed. Obviously these signs should not be
observed with normal use of the medication.
INTERACTIONS WITH OTHER DRUGS
- L-Deprenyl should not be used concurrently with Amitraz (mitaban dips or Preventic tick collars). Other forms of tick control or treatment for demodectic mange should be pursued in infected dogs.
- L-Deprenyl should not be used with Prozac. Because of Prozac’s ability to last a long time in the body, a 5 week period is recommended between the discontinuation of Prozac and the
initiation of L-Deprenyl.
- L-Deprenyl has been associated with serious neurologic side effects when used in conjunction with tricyclic antidepressants or selective serotonin reuptake inhibitors. While these
medications are rarely used in dogs, it is important to be aware of this potential.
- L-Deprenyl should not be used in combination with phenylpropanolamine, a common medication used in the management of urinary incontinence in older dogs. If your dog is already on
phenylpropanolamine and you wish to try L-Deprenyl, it is important to have discontinued phenylpropanolamine for at least 2 weeks before beginning L-Deprenyl. High blood pressure can result from the use of these two medications together.
FOR MORE INFORMATION
The entire product insert for L-Deprenyl can be viewed at
www.anipryl.com/product.asp
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