The Acepromazine is a drug belonging to the family of phenothiazine tranquilizers. In dogs it is usually used as a mild sedative or in combination with other drugs (such as opioids) to achieve deeper sedation. It also has antiemetic effect (prevents vomiting and nausea). Its analgesic effect practically nil.
It is a drug that requires a veterinary prescription and should not be administered without the supervision of a veterinarian. If your dog has been prescribed acepromazine, you are probably wondering what side effects or contraindications it has. In this article on our site we will detail the most outstanding in this species, discover below the side effects of acepromazine in dogs:
1. Hypothermia
It is one of the main adverse effects of acepromazine, due to the peripheral vasodilation it produces. That is why its administration as a single drug is not recommended and care should be taken to keep the animal warm while the effect of the drug lasts.
two. Hypotension
There are breeds that are more sensitive to profound hypotension, vasovagal syndrome and longer sedationThis is the case of brachycephalic breeds (such as boxers or bulldogs) and other large breeds such as greyhounds. In these breeds, lower doses should be used or administration of acepromazine should be avoided.
In any case, due to its vasodilator action, any patient is susceptible to hypotension after taking this drug, which can cause an associated reflex tachycardia and weak pulse. We will avoid using it in hypovolemic animals (for example, with hemorrhages) due to high risk of shock
3. Decreased seizure threshold
In the past, acepromazine has been associated with an increased risk of seizure in sensitive animals, such as those with epilepsy. However, at the doses used in dogs, this risk is currently considered to be very low [1] In any case, it is recommended avoid using it in epileptic patients
4. Third eyelid prolapse
The third eyelid or nictitating membrane usually remains exteriorized for the duration of the effect, but returns to its natural position on its own when the effect wears off. Not clinically significant.
5. Prolonged sedation
It can occur in debilitated or senile patients, who are more sensitive to its effects, as well as the races that we have mentioned in previous points, such as brachycephalics, the sedative effect can be more prolonged and profound and we must take this into account when monitoring these patients once the drug has been administered and when adjusting the dose.
6. Hematocrit decreased
It can decrease it by an average of 17.8% [2], due to the splenic sequestration of red blood cells that occurs, for what should avoid in anemic animals, being important to measure the hematocrit before an intervention, especially in those in which it is estimated that significant blood loss may occur.
7. Incoordination
Due to its depressant effect on the Central Nervous System and decreased motor response, the animal may show instability and incoordination in the gait, especially the posterior third.
8. Disinhibition of aggressive behavior
This is the so-called "paradoxical reaction", in which the animal, instead of being relaxed and calm, becomes hyperactive and even aggressiveThis reaction is more common in cats, but can also occur in dogs. That is why we must be cautious when handling animals under the effects of acepromazine.
Contraindications
Furthermore, acepromazine is considered contraindicated in animals with decompensated heart failure (due to the aforementioned vasodilation), inhepatopathies (since the metabolism of this drug occurs mainly in this organ and hepatotoxicity may occur) and in patients with known allergy to phenothiazines, in pregnancy and lactation (because there is no certainty about its adverse effects at this stage), as well as in cases in which skin allergy tests are being carried out (due to inhibition of histamine H1 receptors).
Finally, this drug has been used frequently in the treatment of various phobias, such as loud noises, storms or firecrackers. Based on the current evidence and taking into account that the motor response is compromised but the patient's sensory perception is hardly diminished, it is considered a treatment that is not very indicated in the treatment of this type of phobia, because the animal continues to perceive everything that frightens it, while its ability to escape is reduced, so it often, the phobia worsens.
