Clonazepam

What is clonazepam?

Clonazepam (brand names: Klonopin®, Antelepsin®, Clonagin®, Clonapam®, CLonax®, Clonex®, Diocam®, Epitril®, Iktorivil®, Kenoket®, Kriadex®, Neuryl®, Paxam®, Rivatril®, Rivotril®, or Solfidin®) is a benzodiazepine antiseizure medication used as a supplemental medication to treat seizures in dogs and cats.

It can also be used to treat anxiety or as a muscle relaxant.

Its use in cats and dogs to treat seizures and behavior problems is off label (extra label). Many drugs are commonly prescribed for off-label use in veterinary medicine. 

“Off label” means the drug is being used in a way that has not been reviewed or approved by the U.S. Food and Drug Administration (FDA) or Health Canada. In these instances, follow your veterinarian’s directions and cautions carefully, as they may be significantly different from those on the label.

How is clonazepam given?

• Clonazepam is given by mouth in the form of a tablet or dissolving tablet.
• Clonazepam can be given with or without food.
• If vomiting occurs after dosing on an empty stomach, give future doses with a meal or a treat.
• Give the first dose under direct supervision to monitor for serious side effects.
• For anxiety and behavior problems, give this medication an hour before the event or trigger.
• Do not stop this medication abruptly; this medication should be tapered off to avoid seizures.

This medication will take effect quickly, in about 1 to 2 hours, and improvement in clinical signs should follow.

What if I miss giving my pet the medication?

If you miss a dose, give it as soon as you remember, and then wait the recommended time as prescribed by your veterinarian for the next dose. Do not give the pet two doses at once.

Are there any potential side effects?

Clonazepam may cause the following side effects:

• Sleepiness
• Incoordination
• Drooling
• Excitement
• Increased appetite (in cats)

There is limited information regarding side effects of this medication in animals, but in humans, the following side effects have occurred:

• Gastrointestinal effects, including increased salivation, vomiting, diarrhea and/or constipation
• Blood effects (anemia, reduced platelets)
• Liver effects

Sudden liver damage may occur in cats. If any of the following signs develop, stop giving clonazepam and contact your veterinarian immediately:

• Vomiting
• Diarrhea
• Lack of appetite
• Yellowing of the skin, eyes, or gums

Other side effects may occur. If you notice anything unusual, contact your veterinarian immediately.  This moderate-acting medication should stop working in a few days, although effects can be longer in pets with liver or kidney disease.

Are there any risk factors for this medication?

DO NOT USE clonazepam in pets that:

• Are allergic to it or other benzodiazepines
• Have significant liver disease

DO NOT USE clonazepam dissolving tablets in dogs, as they contain xylitol, which is toxic to dogs.

USE WITH EXTREME CAUTION in pets that:

• Have glaucoma, liver or kidney disease
• Have myasthenia gravis
• Are sick or debilitated
• Are geriatric
• Are pregnant or lactating
• Are aggressive
• Are working animals

Are there any drug interactions I should be aware of?

The following medications should be used with caution when given with clonazepam:

• Anticholinergic agents
• Antihypertensive agents
• Azole antifungals
• Central nervous system (CNS) depressant drugs
• Cimetidine
• Diltiazem
• Erythromycin
• Phenobarbital

Certain medications may interact with clonazepam, so be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking before starting any new treatment.

Is any monitoring needed with this medication?

• Liver function should be checked regularly in cats.
• Blood levels of the medication may be monitored.
• Your veterinarian will let you know when and how they want to reassess your pet to ensure the medication is working and not causing side effects.
• At home, monitor for any side effects such as those noted above. If any occur, stop using the medication and contact your veterinarian.

How do I store clonazepam?

• Store clonazepam at room temperature (77°F or 25°C) with excursions between 59°F and 86°F (15°C and 30°C) allowed.
• Protect from light and moisture.

Clonazepam is a controlled substance, which means that it has been designated by the Drug Enforcement Administration (DEA) as having a potential for diversion to people other than the patient it was prescribed for. Use of a controlled substance in any person or animal other than that for which it is prescribed is illegal. Therefore, this medication should be stored in a locked cabinet or safe that cannot be easily moved, with access limited to only those that need to administer the medication. Monitor the amount of medication remaining to ensure the expected amount is present.

What should I do in case of emergency?

If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility. Be prepared to provide information about the product and your pet’s weight and symptoms.