Zenalpha 0.5 mg/ml + 10 mg/ml Solution for Injection for Dogs

Nervous or excited dogs with high levels of endogenous catecholamines may exhibit
a reduced pharmacological response to alpha-2 adrenoceptor agonists like
medetomidine (ineffectiveness). In agitated animals, the onset of sedative/analgesic
effects could be slowed, or the depth and duration of effects could be diminished or
non-existent. Therefore, the dog should be given the possibility to calm down before
initiation of the treatment and rest quietly after administration of the product until
evidence of sedation has occurred.

Special precautions for use in animals
In the absence of available data, treatment of puppies less than 4.5 months of age
should be based on a benefit-risk assessment by the responsible veterinarian.
It is recommended that dogs should be fasted in accordance with currently
recommended best practice (e.g. 4 – 6 hours for healthy dogs), prior to treatment
with this veterinary medicinal product. Water can be given.
Animals should be frequently monitored for cardiovascular function and body
temperature during sedation and recovery.
Some cardiovascular effects (e.g. bradycardia, cardiac arrhythmias such as second-
degree AV block or ventricular escape complexes) may be observed after treatment.
Over the period of 15–45 minutes post treatment, blood pressure is likely to decrease
by approximately 30–50 % from pre-treatment levels. Tachycardia with normal blood
pressure may be observed from approximately one hour post-treatment and lasting
up to six hours. Therefore, frequent monitoring of cardiovascular function should
preferably be performed until tachycardia has resolved.
A decrease in body temperature of approximately 1–2°C is likely to occur after
administration.
Once established, hypothermia may persist longer than sedation and analgesia.
To prevent hypothermia, treated animals should be kept warm and at a constant
temperature during the procedure and until fully recovered.
Medetomidine can cause apnoea and/or hypoxaemia. This effect is likely to be
potentiated if used in combination with opioid medicines. Frequent monitoring of
respiratory function should be performed in all cases. It is also advisable to have
oxygen readily available, should hypoxaemia be detected or suspected.
Analgesia provided by the veterinary medicinal product may be shorter than the
sedative effect. Additional pain management should be provided as needed.
Spontaneous muscle trembling or twitching can be expected in some dogs.

Issued: December 2021
AN: 00414/2020
Special precautions to be taken by the person administering the veterinary medicinal
product to animals
Accidental exposure may cause sedation and changes in blood pressure. Caution is
required during treatment administration to avoid accidental self-injection, or skin,
eye or mucosal contact. Adequate restraint of the animal is recommended, as some
animals may react to the injection (e.g., defence reaction).
Pregnant women should administer the veterinary medicinal product with special
caution to avoid self-injection since uterine contractions and decreased foetal blood
pressure may occur after accidental systemic exposure.
People with known hypersensitivity to the active substance or any of the excipients
should administer the veterinary medicinal product with caution.
In case of accidental self-injection or ingestion, seek medical advice immediately and
show the package leaflet to the physician but DO NOT DRIVE.
In case of skin or mucosal contact, wash the exposed skin immediately after
exposure with large amounts of water and remove contaminated clothes that are in
direct contact with skin. In case of eye contact, rinse abundantly with fresh water. If
symptoms occur, seek the advice of a physician.
To the physician: The veterinary medicinal product contains medetomidine, an alpha-
2 adrenoceptor agonist, in combination with vatinoxan, a peripherally selective alpha-
2 adrenoceptor antagonist. Symptoms after absorption may involve clinical effects
including dose-dependent sedation, respiratory depression, bradycardia,
hypotension, a dry mouth, and hyperglycaemia. Ventricular arrhythmias have also
been reported. Respiratory and haemodynamic symptoms should be treated
symptomatically.