Being aware of dexdomitor side effects in dogs is important so that you’re aware of any risks or things to watch for next time your dog is sedated for grooming or for a medical procedure. Fortunately, nowadays many medications used for sedation and anesthesia are very safe. While dexdomitor for dogs is a drug that is considered relatively safe, as with any medications, there are always risks for complications and side effects. Most veterinarians will make clients aware of these risks before their dogs are placed under sedation.
Dexdomitor for Dogs
Dexdomitor for dogs (dexmedetomidine hydrochloride) is an alpha 2 adrenergic agonist drug that is used as a sedative and analgesic (pain reliever, although not strong enough for any surgical procedure). Its main use is to facilitate veterinary examinations and certain clinical and minor surgical procedures.
This drug may also be used as a preanesthetic in dogs prior to the induction of general anesthesia. Use of this drug as a preanesthetic greatly reduces anesthetic requirements in dogs.
Dexdomitor is intended for intramuscular (injected in the muscle) and intravenous use (injected in the muscle or vein). An advantage of Dexdomitor is the fact that this sedative is fully reversible by administering an intramuscular injection of the reversal agent antisedan (atipamezole). This means that as soon as the veterinary procedure is carried out, the reversal agent antisedan can be administered and the dogs can be almost normal again within a matter of minutes.
“Our patients are fully awake and walking within 15 minutes of receiving antisedan,” explains veterinarian Dr. Michael Salkin. Of course though, every dog handles these drugs differently and individual variances may take place on a case-by-case basis. It may therefore happen that some dogs may be discharged within 30 minutes.
According to the drug’s information leaflet, dexdomitor is administered at a dose of 500 mcg/m2 intramuscularly (IM) or 375 mcg/m2 intravenously (IV) for the purpose of sedation and analgesia and at a dose of 125 or 375 mcg/m2 intramuscularly as preanesthetic. Dosages as a preanesthetic tend to vary based on the duration and severity of the procedure as outlined below.
” There are two approved dosing options for use as a preanesthetic: 125 mcg/m2 given IM for cooperative sedation that allows most dogs to remain ambulatory, a useful option for larger patients or 375 mcg/m2 given IM for deeper sedation, a useful option for patients requiring procedures of extended duration or associated with severe pain.” Dr. Grimm DVM
Things to Be Aware of
It is recommended that dogs are fasted for 12 hours before the use of Dexdomitor. Upon injected with dexdomitor, the sedation and analgesia effect tend to take place within 5 (when administered intravenously ) to 15 minutes (when administered intramuscularly), with peak effects at 15 to 30 minutes respectively.
Per the product insert recommendations, dexdomitor should not be used in dogs with cardiovascular disease, respiratory disorders and liver or kidney diseases. Dexdomitor should also not be used in dogs that are severely debilitated, in shock or in a state of stress from excessive heat, cold or fatigue.
Dexdomitor should not be administered to dogs suffering from preexisting low blood pressure, deficiency in the amount of oxygen reaching the tissues or a slow heart rate.
Dexdomitor works by initially increasing blood pressure followed by normal or slightly below normal levels. Vasoconstriction, the constriction of blood vessels in an attempt to raise blood pressure by sending blood to vital organs, may lead to pale or mildly bluish mucous membranes (gums, tongue). This response is often accompanied by a lower heart rate, weak pulse, lowered respiratory rate and decreased body temperature.
Along with these changes, there is depression of the motility of the dogs’s gastrointestinal tract along with increased blood glucose levels and increased production of urine. Twitching of muscles may also take place.
“The only time I have ever heard of a death related to Domitor, is if a pet has an underlying health problem (sometimes it’s a previously undiagnosed problem, such as a heart condition that was not detectable, but may be found on an autopsy after the death), or if a pet has a reaction to the sedative, or if the Domitor was mixed with another sedative, and the pet reacted to one of the other sedatives in the mixture. “~Dr. Dave, veterinarian.
Complications During/After the Procedure
During the procedure, dogs should be frequently monitored for correct cardiovascular function and ideal body temperature during sedation or anesthesia. According to a study involving 106 dogs ranging in age from 16 weeks and 16 years, the administration of dexdomitor for sedation/analgesia purposes resulted is the several adverse reactions.
A possible complication from use of this drug is apnea, the temporary cessation of breathing. Should this happen, additional oxygen will need to be administered. If the apnea is accompanied by low heart rate and bluish/pale mucous membranes (gums, tongue etc.) the sedation should be reversed with antisedan.
In the study, in 19 out of 106 dogs, a heart arrhythmia was detected. Sometimes such arrhythmias were detected at various points. Such arrhythmias decreased once the reversal agent antisedan was administered. One dog out of 106 developed severe low heart rate another dog out of 106 developed apnea, while two dogs developed lowered body temperature (hypothermia). To prevent hypothermia, dogs should be kept warm during the procedure until fully recovered. Such lowered temperature may persist and last longer than the actual sedation/analgesia period.
In 3 dogs out of 106, the administration of dexdomitor was ineffective. Three dogs were basically standing throughout the study. The drug had a slow onset of sedation in one dog out of 106 with the drug taking over 30 minutes to take effect. Finally, during recovery, one dog out of 106 sustained prolonged recovery times.
“The biggest risk of any medication used for sedation is respiratory and or cardiovascular depression that could lead to death. This should be understood by every client who is having their pet placed under sedation… Now with that being said, dexdomitor is a great drug for sedation because it can be very quickly reversed with a drug called antisedan.”~Dr. Whitehead, veterinarian
Dexdomitor Side Effects in Dogs
Once the dog is released to the owner’s care, dog owners may wish to monitor their dogs for possible side effects taking place during the recovery time.
Generally, when administered intravenously, the effect of dexdomitor wanes after 2 hours of its administration or by 3 hours when administered intramuscularly.
When dogs come out of the sedation, they may sometimes act out of character. Veterinarian Dr. Whitehead warns owners to be careful with their pets after sedation, avoiding quick actions, loud noises and allowing them to recover in a quiet room for the rest of the day. He mentions having witnessed dogs snap and attempt to bite their owners or other people.
Other side effects that may be noted by dog owners include a brief state of excitement or apprehensiveness and in some cases, tremors, increased salivation and diarrhea.
Many dog owners may wonder whether giving a lower dosage of dexdomitor may lower the chances for the risks of cardiovascular changes associated with this drug as explained above. The answer is no, lower dosages of dexdomitor will not prevent these cardiovascular changes but will reduce the duration of these effects, explains veterinarian Dr. Kurt A. Grimm.
So what sedatives are ideal for cardiac patients? According to Donald Brown, a board-certified veterinary cardiologist, his concoction of choice consists of diazepam (Valium) and butorphanol mixed for an IV injection, as it stings if given out of the vein. Alternatively, midazolam can be used in lieu of diazepam IM for dogs who can’t sit still for an IV.
“This class of drug (dexdomitor, an alpha 2 adrenergic agonist drug) is only an appropriate choice for relatively healthy patients and cannot be used on any patient with cardiac compromise. Alpha-2s cause vomiting in most cats and many dogs, though this is much less when given intravenously. “~ Katrina Lafferty, DVM
And What About Antisedan?
Antisedan (atipamezole hydrochloride) is the drug used for the reversal of the sedative/analgesic Dexdomitor. This drug is administered intramuscularly (IM). For the reversal of IV dexdomitor, the dose is 3750 mcg/m2, while for reversal of IM dexdomitor the dose is 5000 mcg/m2. As with dexdomitor, the mcg/kg dosage decreases the higher the dog’s body weight.
How long does antisedan take to work? According to the package insert, peak serum concentrations are reached in about 10 minutes. Awakening signs usually become noticeable within 5 to 10 minutes of its injection, but the timeframe may vary based on the depth and duration of dexdomitor. The half-life (time frame necessary for its concentration in the body to decrease by half) is less than 3 hours.
Because antisedan works so quickly, veterinary staff needs to be on the lookout for potential apprehensive or aggressive behavior especially in dogs predisposed to nervousness or fright. Caution will be needed to prevent falls if the dog is on a surgical table.
A relapse to sedation is also a possibility. Vet staff need to be on the lookout for persistent low body temperatures, lowered heart rate, and depressed respiration, until the dog appears to be recovering. Adverse reactions are more likely in dogs who are debilitated, geriatric and ill especially those with a compromised cardiovascular system.
Side effects of antisedan include occasional vomiting, excitement or apprehensiveness, increased salivation diarrhea, and tremors.
- Zoetis Dexdomitor Package Insert
- Zoetis Antisedan Package Insert