(Reconcile, Prozac)
Wendy C. Brooks, DVM, DipABVP
Educational Director, VeterinaryPartner.com
Fluoxetine
(Reconcile, Prozac)
Brand Name: Reconcile, Prozac
Available in 10 mg tablets; 10 mg,
20 mg, 40 mg capsules; oral liquid; and 8 mg, 16 mg, 32 mg, 64 mg
chewable tablets for dogs
Background Anxiety,
obsessive-compulsive disorder, and depression are common problems for
humans and the development of drugs that alleviate these conditions is
ongoing so currently there are many medications on the market for these
uses. A popular class of anti-anxiety medications is the selective
serotonin reuptake inhibitors, also called SSRIs for short.
Serotonin is a
neurotransmitter in the brain associated, among other things, with mood
elevation and reduced aggression. Increasing serotonin in the brain
means less anxiety and a happier attitude. By inhibiting the brain’s
system for removing used serotonin, SSRIs cause serotonin to linger,
lasting longer. The more serotonin we have in our brains, the less
anxiety, obsession, and depression we get.
Eli Lilly, a
pharmaceutical company, tested many related compounds and released
fluoxetine as the most specific SSRI of all of them. Fluoxetine,
marketed under the brand name Prozac®, was not quite the first SSRI
on the human market but quickly became the most popular.
It was not long
after that that fluoxetine found its way into veterinary use for
animals with anxiety, compulsive behavior, and other behavior issues.
When low-cost generic fluoxetine became available, its use increased in
the veterinary market, and in 2007 Eli Lilly released a version of
fluoxetine specifically labeled for animal use.
How
this Medication is Used Fluoxetine has
been used in many animal behavior issues: inappropriate urine marking
in dogs and cats; separation anxiety; compulsive chewing; circling;
self-mutilation; and even aggression. In 2007 Eli Lilly released a
product approved for dogs called Reconcile®. This product is
specifically approved for the treatment of separation anxiety.
It should be
noted that the treatment of behavior disorders requires training in
addition to simply giving the pet a medication. In the instance of
separation anxiety, Eli Lilly has trademarked the B.O.N.D. training
program. Our on-line web library also has information (see link
above). When medication and treatment were combined, 42% of dogs with
separation anxiety showed improvement by the end of the first week and
73% were improved within 8 weeks.
Fluoxetine is
usually given once daily.
Side
Effects It is important
to understand that whenever an anti-anxiety medication is used, the
phenomenon of disinhibition is possible. What this means is that an
animal’s inhibitions about aggressive behavior may be reduced when his
or her anxiety over the consequences of such behavior is removed. An
animal that was not previously aggressive could potentially become
aggressive.
The most common
side effect is drowsiness or lethargy.
Appetite
reduction is a common side effect of fluoxetine in dogs. Approximately
22% of the dogs in the Reconcile® licensing studies showed 5 to 10%
weight loss on this medication while 6% showed 10 to 15% weight loss.
In other words, these dogs lost 5 to 10% or 10 to 15% of their initial
body weight while taking fluoxetine.
Some patients
will experience an upset stomach with this medication.
Interactions
with Other Drugs Fluoxetine
should not be used in combination with drugs that could increase the
likelihood of seizures, such as acepromazine.
Fluoxetine
should not be given in conjunction with a monoamine oxide inhibitor
(MAO inhibitor) such as selegiline or amitraz. This includes amitraz
containing collars such as the Preventic® collar, dips such as
Mitaban® dip, and flea products such as Promeris® for dogs.
Concerns
and Cautions This medication
is best not used in patients with diabetes mellitus or with seizure
disorders.
