THE PET PHARMACY By Wendy C. Brooks, DVM, DipABVP Educational Director, VeterinaryPartner.com

(for veterinary information only)

Brand Name: Xanax

Available in 0.25 mg, 0.5 mg, 1 mg, and 2 mg tablets

Background

Alprazolam, like its more famous cousin diazepam (Valium®), is a benzodiazepine tranquilizer. It works by depressing activity in a number of areas of the brain, which leads to several desired effects. It works as an anti-anxiety treatment, as a sedative, as a suppressor of seizure activity, and as a muscle relaxer. The exact mechanism for creating these effects is unknown. Alprazolam represents an improvement on the original diazepam in that it lasts longer.

How this Medication Is Used

The most common veterinary use for this medication is probably the treatment of panic disorders in dogs. Panic disorders differ from other forms of anxiety in that they have a more acute basis and seem to be associated with loud noise stimuli like fireworks or thunderstorms. Typically a single dose of alprazolam could relax a dog on the evening of the Fourth of July or during a single storm, and on-going medication would not be needed to see an effect. Other anti-anxiety medications require weeks of use for results and would not be helpful in these types of unique short-term situations.

Other uses might include anxiety disorders in cats, such as with inappropriate elimination.

Alprazolam is also sometimes used to supplement seizure control medications such as phenobarbital when one medication alone is inadequate.

Alprazolam seems to exert its maximum effect within 1 to 2 hours.

Side Effects

Sedation is a possible side effect.

In cats, cases of liver failure have been reported after diazepam is used for several days, and since alprazolam is closely related, a similar reaction is possible. It would be a good idea to check a cat's liver enzymes both before beginning therapy and again a few days after starting. Any increase in enzymes precludes the use of oral alprazolam in such a patient.

Interactions with Other Drugs

Alprazolam may have a stronger than expected effect if used in conjunction with cimetidine (an antacid more commonly known as Tagamet), erythromycin (an antibiotic), ketoconazole (an antifungal drug), itraconazole (another antifungal drug), or propranolol (a heart medication).

Antacids may slow the onset of effect of alprazolam.

The use of alprazolam may increase the effect of digoxin, a heart medication.

Concerns and Cautions

• This medication should be stored at room temperature and protected from light.
• Liver disease can prolong the activity of alprazolam. Alprazolam should be used with caution or not at all in patients with liver or kidney insufficiency.
• There is a risk of using anti-anxiety medications such as this in aggressive animals as a phenomenon called “disinhibition” may be observed. What this means is that the medication may remove whatever inhibitions the animal had to suppress aggression and the situation can be aggravated now that the patient is no longer inhibited. DO NOT ADMINISTER A PET'S FIRST-EVER DOSE OF ALPRAZOLAM AND THEN LEAVE HIM UNSUPERVISED. ALWAYS SUPERVISE A TEST DOSE TO BE SURE PETS ARE NOT OVER-TRANQUILIZED OR AGGRESSIVE WITH ONE ANOTHER.
• Discontinuing alprazolam abruptly may lead to unpleasant withdrawal symptoms similar to those that occur in humans.
• Alprazolam should not be used in early pregnancy; birth defects have been reported.
• Alprazolam also crosses readily into the milk of nursing mothers and may tranquilize nursing young. Alprazolam should thus not be used in nursing mothers.

ALPRAZOLAM IS A CONTROLLED SUBSTANCE AND SPECIAL RECORDS MUST BE KEPT BY VETERINARIANS PRESCRIBING IT.

It is our policy not to give dosing information over the Internet.

Date Published: 6/18/2007 10:39:00 AM
Date Reviewed/Revised: 01/11/2010