Buspirone Hydrochloride

(for veterinary information only)

BRAND NAME: BUSPAR

AVAILABLE IN 
5 mg, 10 mg, 15 mg
TABLETS      

BACKGROUND

The relief of anxiety is an area of human medicine which has received a great deal of pharmaceutical attention. In the beginning, there were only tranquilizers, such as diazepam, which were helpful but also addictive and had undesirable drowsiness side effects. The development of non-addictive non-sedating medications to relieve anxiety (called anxiolytic drugs) has been an important area of pharmacology in the last 20 years. The development of buspirone, a member of the azapirone class of anxiolytics, stems from this research. Buspirone is able to relieve anxiety with minimal sedation, minimal muscle relaxation, and no addiction potential.

HOW THIS MEDICATION IS USED

In veterinary medicine, buspirone has been especially helpful in the treatment of urine marking in cats. As with people, in the beginning there were tranquilizers such as diazepam (valium®). Prior to the use of diazepam, strong female hormones (progestins) has been the favored treatment. Happily, diazepam was free from the unpleasant side effects of hormone therapy but, unfortunately, the problem behavior typically returned when the diazepam was discontinued. When buspirone was used, a sustained effect was seen such that after an eight week course, medication could be discontinued, in many cases permanently, without recurrence of urine marking.

Buspirone requires several weeks of administration to achieve effectiveness. Single doses would not be expected to be effective. It is not a helpful drug for panic-like syndromes (like thunderstorm phobias) either in humans or in animals but is effective for more generalized anxiety.

SIDE EFFECTS

The most commonly observed side effect with this medication is an increase in affectionate behavior in the cat. This may not sound problematic but some owners complain of not being able to sleep through the aggressive purring and rubbing. Any drug that modifies behavior has potential to reduce a catís inhibitions thus making other behavioral changes, including aggression, possible.

Side effects that have been reported by humans taking buspirone include: nausea, headache, dizziness, appetite loss, and restlessness.

Increases in heart rate have been an occasionally noted side effect in humans.

INTERACTIONS WITH OTHER DRUGS

Buspirone should not be used in conjunction with monoamine oxidase inhibitors such as Deprenyl. Dangerous episodes of high blood pressure ("serotonin syndrome") can result when these medications are used in conjunction.

The following medications can increase the blood levels of buspirone thus increasing the potential for side effects:

CONCERNS AND CAUTIONS

  • Buspirone is best taken on an empty stomach according to the manufacturer; however, the presence of food in the stomach with buspirone is likely not to be an important factor in how this medication is absorbed.
     
  • Buspirone tablets should be stored in a way that protects them from light exposure.
     
  • This medication should be used cautiously in patients with either liver or kidney disease.
     
  • Buspirone has not been shown to be safe for use in pregnancy. It definitely crosses into the mammary gland and can be passed to nursing young.

Page last updated: 8/9/2013