Ketamine

What is ketamine?

Ketamine (brand name Ketaset®) is an NMDA-receptor antagonist used to facilitate restraint/immobilization and to induce anesthesia for surgical procedures in cats, dogs, rabbits, rodents, birds, reptiles, and other animals. It may also be used for adjunctive pain control for post-surgical or chronic pain.

It is labeled for use as a restraint and anesthetic agent in cats; all other uses are 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 do I give my pet ketamine?

• Ketamine comes in an injectable form.
• Injections are given intravenously (into a vein), intramuscularly (into a muscle), or subcutaneously (under the skin).
• Your veterinarian will administer the medication. Ketamine is a controlled substance.
• Give this medication to your pet for the entire time prescribed by your veterinarian, even if it appears that your pet is feeling better.

This medication should take effect quickly, within minutes to 1 hour, depending on the route of administration.

What if I miss giving my pet the medication?

Contact your veterinarian for recommendations. Do not give the pet two doses at once.

Are there any potential side effects from ketamine?

Ketamine may cause the following side effects:

• Vomiting, drooling
• Prolonged recovery or agitation after anesthesia
• Muscle twitches or tremors

The following reactions are rare, but if they occur, contact your veterinarian immediately:

• An allergic reaction such as irregular breathing, rash, fever, puffiness and swelling around the face
• Seizures

Drug sensitivities can develop over time with repeated exposure. Your pet may have no reaction after the first few doses, but may develop a sensitivity later. It is important to watch for signs of an allergic reaction over the entire course of treatment. 

Other side effects may occur. If you notice anything unusual, contact your veterinarian immediately. This medication is short-acting, meaning that effects will last less than 24 hours, though effects may last longer in pets with kidney or liver disease

Are there any risk factors for this medication?

DO NOT USE ketamine in animals who:

• Are allergic to any component of the medication or similar medications (e.g., tiletamine)
• Have heart disease and/or severe hypertension
• Have severe kidney or liver disease

USE WITH CAUTION in animals who:

• Have a seizure disorder or history of seizures
• Have hyperthyroidism
• Have increased intraocular pressure (IOP)

Are there any drug interactions I should be aware of?

Certain medications should be USED WITH CAUTION when given with ketamine, including: 

• Barbiturates (e.g., phenobarbital)
• Benzodiazepines (e.g., diazepam)
• CNS depressants (e.g., gabapentin, methocarbamol)
• Fluconazole
• Ivermectin
• Opioids (e.g., buprenorphine, fentanyl)
• Other anesthetic or sedative agents (e.g., dexmedetomidine, lidocaine)
• Sympathomimetics (e.g., albuterol, phenylpropanolamine) 
• Theophylline
• Thyroid hormones

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?

• Your veterinarian will monitor vital signs throughout the immobilization or anesthetic time.
• Your veterinarian may schedule follow-up visits for monitoring. In this case, follow your veterinarian’s directions.
• At home, monitor urine output and for abnormal changes. If these occur, discontinue the medication and contact your veterinarian.

How do I store ketamine?

• Your veterinarian will store at room temperature, protected from light.
• Follow manufacturer’s directions for product specific discard times.
• Keep medication out of reach of children and pets.

Ketamine 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. The amount of medication must be carefully monitored.  

What should I do in case of emergency?

If you suspect an overdose or an adverse reaction, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility. Adverse effects should be reported to the FDA or Health Canada.