Target species
Dogs and cats.
Indications for use for each target species
Non-invasive, mildly to moderately painful, procedures and examinations which require restraint, sedation and analgesia in dogs and cats.
Deep sedation and analgesia in dogs in concomitant use with butorphanol for medical and minor surgical procedures.
Premedication in dogs and cats before induction and maintenance of general anaesthesia.
To be administered intravenously as a constant rate infusion (CRI) in dogs and cats as part of a multimodal protocol during inhalation anaesthesia.
Contraindications
Do not use in animals with cardiovascular disorders.
Do not use in animals with severe systemic disease or in animals that are moribund.
Do not use in case of known hypersensitivity to the active substance or to any of the excipients.
Special warnings
The administration of dexmedetomidine to puppies younger than 16 weeks and kittens younger than 12 weeks has not been studied.
Special precautions for use
Special precautions for safe use in the target species:
Treated animals should be kept warm and at a constant temperature, both during the procedure and recovery.
It is recommended that animals are fasted for 12 hours prior to Dexdomitor administration. Water may be given.
After treatment, the animal should not be given water or food before it is able to swallow.
Corneal opacities may occur during sedation. The eyes should be protected by a suitable lubricant.
To be used with precaution in elderly animals.
Nervous, aggressive or excited animals should be given the possibility to calm down before initiation of treatment.
Frequent and regular monitoring of respiratory and cardiac function should be performed. Pulse oximetry may be useful but is not essential for adequate monitoring. Equipment for manual ventilation should be available in case of respiratory depression or apnoea when dexmedetomidine and ketamine are used sequentially to induce anaesthesia in cats. It is also advisable to have oxygen readily available, should hypoxaemia be detected or suspected.
Sick and debilitated dogs and cats should only be premedicated with dexmedetomidine before induction and maintenance of general anaesthesia based on a risk-benefit assessment.
Use of dexmedetomidine as a premedicant in dogs and cats significantly reduces the amount of induction drug required for induction of anaesthesia. Attention should be given during the administration of intravenous induction drugs to effect. Volatile anaesthetic requirements for maintenance anaesthesia are also reduced.
When using dexmedetomidine as a constant rate infusion during inhalation anaesthesia, adequate monitoring of respiratory and cardiovascular functions, oxygen supplementation and access to mechanical ventilation should be available. Dexmedetomidine CRI reduces the dose of inhalational anaesthetic required for maintenance of general anaesthesia.
Special precautions to be taken by the person administering the veterinary medicinal product to animals:
In case of accidental oral intake or self-injection, seek medical advice immediately and show the package leaflet or the label to the physician but DO NOT DRIVE as sedation and changes in blood pressure may occur.
Avoid skin, eye or mucosal contact; the use of impermeable gloves is advisable. 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.
If pregnant women handle the product, special caution should be observed not to self-inject as uterine contractions and decreased foetal blood pressure may occur after accidental systemic exposure.
Advice to physicians: Dexdomitor is an α2-adrenoreceptor agonist, 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. The specific α2-adrenoceptor antagonist, atipamezole, which is approved for use in animals, has been used in humans only experimentally to antagonise dexmedetomidine-induced effects.
People with known hypersensitivity to the active substance or any of the excipients should administer the veterinary medicinal product with caution.
Special precautions for the protection of the environment:
Not applicable.
Adverse events
Dogs:
Very common (>1 animal/ 10 animals treated):: | Bradycardia Cyanotic mucous membranes2 Pale mucous membranes2 |
Common (1 to 10 animals / 100 animals treated): | Arrhythmia1 |
Rare (1 to 10 animals / 10 000 animals treated): | Pulmonary oedema |
Undetermined frequency (cannot be estimated from the available data): | Excitation1 Heart block1 High blood pressure3 Low blood pressure3 Premature ventricular contractions1 Supraventricular and nodal arrhythmia1 Hypersalivation1 Retching1 Vomiting4 Corneal opacity Muscle tremor Sedation prolonged1 Bradypnoea1,5 Decreased pulse oxygenation1 Decreased respiratory rate Irregular breathing1 Tachypnoea1,5 Erythema1 Decreased body temperature Urination1 |
1When dexmedetomidine and butorphanol are used concomitantly.
2Due to peripheral vasoconstriction and venous desaturation in the presence of normal arterial oxygenation.
3Blood pressure will increase initially and then return to normal or below normal.
4May occur 5–10 minutes after injection. Some dogs may also vomit at the time of recovery.
5When dexmedetomidine is used as a premedicant.
When dexmedetomidine and butorphanol are used concomitantly in dogs, brady- and tachyarrhythmias have been reported. These may include profound sinus bradycardia, 1st and 2nd degree AV block, sinus arrest or pause, as well as atrial, supraventricular and ventricular premature complexes.
When dexmedetomidine is used as a premedicant brady- and tachyarrhythmias have been reported and include profound sinus bradycardia, 1st and 2nd degree AV block and sinus arrest. Supraventricular and ventricular premature complexes, sinus pause and 3rd degree AV block may be observed in rare cases.
Cats:
Very common (> 1 animal / 10 animals treated): | Arrhythmia1 Bradycardia Heart block2 Vomiting3 Pale mucous membranes4 Cyanotic mucous membranes4 |
Common (1 to 10 animals / 100 animals treated): | Supraventricular and nodal arrhythmia1 Retching1 Decreased pulse oxygenation2 Hypothermia2 |
Uncommon (1 to 10 animals / 1 000 animals treated): | Apnoea2 |
Rare (1 to 10 animals / 10 000 animals treated): | Pulmonary oedema |
Undetermined frequency (cannot be estimated from the available data): | Extrasystole2 High blood pressure5 Low blood pressure5 Corneal opacity Muscle tremor Bradypnoea2 Decreased respiratory rate Hypoventilation2 Irregular breathing2 Agitation2 |
1When dexmedetomidine is used as a premedicant.
2When dexmedetomidine and ketamine are used sequentially.
3May occur 5–10 minutes after injection. Some cats may also vomit at the time of recovery.
4Due to peripheral vasoconstriction and venous desaturation in the presence of normal arterial oxygenation.
5Blood pressure will increase initially and then return to normal or below normal.
Intramuscular dosing at 40 µg/kg (followed by ketamine or propofol) frequently resulted in sinus bradycardia and sinus arrhythmia, occasionally resulted in 1st degree atrioventricular block, and rarely resulted in supraventricular premature depolarizations, atrial bigeminy, sinus pauses, 2nd degree atrioventricular block, or escape beats/rhythms.
Constant rate infusion
Very common (> 1 animal /10 animals treated): | Bradycardia Heart block1 High blood pressure Low blood pressure Decreased pulse oxygenation Hypersalivation Vomiting Muscle twitching Agitation Prolonged recovery Vocalisation |
1II-degree AV block
Reporting adverse events is important. It allows continuous safety monitoring of a veterinary medicinal product. Reports should be sent, preferably via a veterinarian, to either the marketing authorisation holder or its local representative or the national competent authority via the national reporting system. See the package leaflet for respective contact details.
Use during pregnancy, lactation or lay
Pregnancy and lactation:
The safety of dexmedetomidine has not been established during pregnancy and lactation in the target species. Therefore the use of the product during pregnancy and lactation is not recommended.
Fertility:
The safety of dexmedetomidine has not been established in males intended for breeding.
Interaction with other medicinal products and other forms of interaction
The use of other central nervous system depressants is expected to potentiate the effects of dexmedetomidine and therefore an appropriate dose adjustment should be made. Anticholinergics should be used with caution with dexmedetomidine.
Administration of atipamezole after dexmedetomidine rapidly reverses the effects and thus shortens the recovery period. Within 15 minutes dogs and cats are normally awake and standing.
Cats: After administration of 40 µg dexmedetomidine/kg bw intramuscularly concurrently with 5 mg ketamine/kg bw to cats, the maximum concentration of dexmedetomidine increased twofold but there was no effect on T max. The mean half-life of elimination of dexmedetomidine increased to 1.6 h and the total exposure (AUC) increased by 50 %.
A dose of 10 mg ketamine/ kg used concurrently with 40 µg dexmedetomidine/ kg may cause tachycardia.
For information on adverse reactions, see section Adverse events.
For information on target animal safety in cases of overdosing, see section Overdose.
Administration routes and dosage
The product is intended for:
- Dogs: intravenous or intramuscular use
- Cats: intramuscular use
The product is not intended for repeat injections.
Dexdomitor, butorphanol and/or ketamine can be mixed in the same syringe as they have been shown to be pharmaceutically compatible.
When the product is to be used as a CRI it must be diluted with sodium chloride 9 mg/ml (0.9 %) solution or Ringer’s lactate solution prior to administration. The diluted intravenous infusion should be delivered by a syringe pump or infusion pump.
It is recommended that the CRI is delivered via a separate syringe pump or a dedicated infusion line, in parallel with maintenance fluids. The maintenance fluid rate should be adjusted according to the CRI fluid rate to maintain the chosen total volume administered and to avoid overhydration, also in case of potential CRI fluid rate adjustment or stopping.
Accurate dilution is essential given the small drug volumes involved. Appropriately graduated syringes should be used.
Dosage: the following doses are recommended:
DOGS:
Dexmedetomidine doses are based on body surface area:
Intravenously: up to 375 µg/square metre body surface area
Intramuscularly: up to 500 µg/square metre body surface area
When administering in conjunction with butorphanol (0.1 mg/kg) for deep sedation and analgesia, the intramuscular dose of dexmedetomidine is 300 µg/square metre body surface area. The premedication dose of dexmedetomidine is 125–375 µg/square metre body surface area, administered 20 minutes prior to induction for procedures requiring anaesthesia. The dose should be adjusted to the type of surgery, length of procedure and patient temperament.
Concomitant use of dexmedetomidine and butorphanol produces sedative and analgesic effects beginning no later than 15 minutes. The peak sedative and analgesic effects are reached within 30 minutes after administration. Sedation lasts for at least 120 minutes post administration and analgesia lasts for at least 90 minutes. Spontaneous recovery occurs within 3 hours.
Premedication with dexmedetomidine will significantly reduce the dosage of the induction agent required and will reduce volatile anaesthetic requirements for maintenance anaesthesia. In a clinical study, the requirement for propofol and thiopental was reduced by 30 % and 60 % respectively. All anaesthetic agents used for induction or maintenance of anaesthesia should be administered to effect. In a clinical study, dexmedetomidine contributed to postoperative analgesia for 0.5–4 hours. However this duration is dependent on a number of variables and further analgesia should be administered in accordance with clinical judgement.
The corresponding doses based on body weight are presented in the following tables. Use of an appropriately graduated syringe is recommended to ensure accurate dosing when administering small volumes.
Dog weight (kg) | Dexmedetomidine 125 µg/m2 | Dexmedetomidine 375 µg/m2 | Dexmedetomidine 500 µg/m2 |
| (µg/kg) | (ml) | (µg/kg) | (ml) | (µg/kg) | (ml) |
2–3 | 9.4 | 0.04 | 28.1 | 0.12 | 40 | 0.15 |
3-4 | 8.3 | 0.05 | 25 | 0.17 | 35 | 0.2 |
4-5 | 7.7 | 0.07 | 23 | 0.2 | 30 | 0.3 |
5-10 | 6.5 | 0.1 | 19.6 | 0.29 | 25 | 0.4 |
10-13 | 5.6 | 0.13 | 16.8 | 0.38 | 23 | 0.5 |
13-15 | 5.2 | 0.15 | 15.7 | 0.44 | 21 | 0.6 |
15-20 | 4.9 | 0.17 | 14.6 | 0.51 | 20 | 0.7 |
20-25 | 4.5 | 0.2 | 13.4 | 0.6 | 18 | 0.8 |
25-30 | 4.2 | 0.23 | 12.6 | 0.69 | 17 | 0.9 |
30-33 | 4 | 0.25 | 12 | 0.75 | 16 | 1.0 |
33-37 | 3.9 | 0.27 | 11.6 | 0.81 | 15 | 1.1 |
37-45 | 3.7 | 0.3 | 11 | 0.9 | 14.5 | 1.2 |
45-50 | 3.5 | 0.33 | 10.5 | 0.99 | 14 | 1.3 |
50-55 | 3.4 | 0.35 | 10.1 | 1.06 | 13.5 | 1.4 |
55-60 | 3.3 | 0.38 | 9.8 | 1.13 | 13 | 1.5 |
60-65 | 3.2 | 0.4 | 9.5 | 1.19 | 12.8 | 1.6 |
65-70 | 3.1 | 0.42 | 9.3 | 1.26 | 12.5 | 1.7 |
70-80 | 3 | 0.45 | 9 | 1.35 | 12.3 | 1.8 |
>80 | 2.9 | 0.47 | 8.7 | 1.42 | 12 | 1.9 |
For deep sedation and analgesia with butorphanol |
Dog weight (kg) | Dexmedetomidine 300 µg/m2 intramuscularly (µg/kg) | Dexmedetomidine 300 µg/m2 intramuscularly (ml) |
2-3 | 24 | 0.12 |
3-4 | 23 | 0.16 |
4-5 | 22.2 | 0.2 |
5-10 | 16.7 | 0.25 |
10-13 | 13 | 0.3 |
13-15 | 12.5 | 0.35 |
15-20 | 11.4 | 0.4 |
20-25 | 11.1 | 0.5 |
25-30 | 10 | 0.55 |
30-33 | 9.5 | 0.6 |
33-37 | 9.3 | 0.65 |
37-45 | 8.5 | 0.7 |
45-50 | 8.4 | 0.8 |
50-55 | 8.1 | 0.85 |
55-60 | 7.8 | 0.9 |
60-65 | 7.6 | 0.95 |
65-70 | 7.4 | 1 |
70-80 | 7.3 | 1.1 |
> 80 | 7 | 1.2 |
Constant rate infusion
When administered as CRI under inhalation anaesthesia, the dose is 0.5–1 microgram/kg/h, iv initiated by a loading dose of 0.5–1 microgram/kg, iv given over 10 minutes.
When dogs are premedicated with dexmedetomidine, a loading dose is not needed.
The infusion of dexmedetomidine in dogs under inhalation anaesthesia will reduce the dose of drug required for maintenance of anaesthesia about 30 %. The dose of inhalational anaesthetic must be titrated to effect. The dose of other analgesic drugs administered together may require adjustments based on the procedure and on the clinical judgement.
Small dogs: prepare a 1 microgram/ml concentration:
1. For 50 or 60 ml syringe, mix 0.1 ml dexmedetomidine (0.5 mg/ml) with 49.9 ml of sodium chloride 9 mg/ml (0.9 %) solution or Ringer’s lactate solution, yielding a final volume of 50 ml.
2. For 100 ml sodium chloride bottle, replace 0.2 ml of sodium chloride solution with 0.2 ml of dexmedetomidine (0.5 mg/ml).
Administer 0.5 ml/kg/h of this dilution for 0.5 microgram/kg/h or 1 ml/kg/h for 1 microgram/kg/h dose rates.
Larger dogs: prepare a 5 micrograms/ml concentration:
1. For 50 or 60 ml syringe, mix 0.5 ml of dexmedetomidine (0.5 mg/ml) with 49.5 ml of sodium chloride 9 mg/ml (0.9 %) solution or Ringer’s lactate solution.
2. For 100 ml sodium chloride bottle, replace 1 ml of sodium chloride solution with 1 ml of dexmedetomidine (0.5 mg/ml).
Administer 0.1 ml/kg/h of this dilution for 0.5 microgram/kg/h or 0.2 ml/kg/h for 1 microgram/kg/h dose rates.
CATS:
The dosage for cats is 40 µg dexmedetomidine hydrochloride/kg bw equal to a dose volume 0.08 ml Dexdomitor/kg bw when used for non-invasive, mildly to moderately painful procedures requiring restraint, sedation and analgesia.
When dexmedetomidine is used for premedication in cats, the same dose is used. Premedication with dexmedetomidine will significantly reduce the dosage of the induction agent required and will reduce volatile anaesthetic requirements for maintenance anaesthesia. In a clinical study, the requirement for propofol was reduced by 50%. All anaesthetic agents used for induction or maintenance of anaesthesia should be administered to effect.
Anaesthesia can be induced 10 minutes after premedication by intramuscular administration of a target dose of 5 mg ketamine/ kg bw or by intravenous administration of propofol to effect. Dosing for cats is presented in the following table.
Cat weight (kg) | Dexmedetomidine 40 µg/kg intramuscularly (µg/kg) | Dexmedetomidine 40 µg/kg intramuscularly (ml) |
1-2 | 40 | 0.1 |
2-3 | 40 | 0.2 |
3-4 | 40 | 0.3 |
4-6 | 40 | 0.4 |
6-7 | 40 | 0.5 |
7-8 | 40 | 0.6 |
8-10 | 40 | 0.7 |
The expected sedative and analgesic effects are reached within 15 minutes after administration and are maintained up to 60 minutes after administration. Sedation may be reversed with atipamezole. Atipamezole should not be administered prior to 30 minutes following ketamine administration.
Constant rate infusion
When administered as CRI under inhalation anaesthesia, the dose is 0.5–3 micrograms/kg/h, iv initiated by a loading dose of 0.5–1 microgram/kg, iv given over 10 minutes.
When cats are premedicated with dexmedetomidine, a loading dose is not needed. The infusion of dexmedetomidine in cats under inhalation anaesthesia will reduce the dose of the drug required for maintenance of anaesthesia. The dose of inhalational anaesthetic must be titrated to effect. The dose of other analgesic drugs administered together may require adjustments based on the procedure and on the clinical judgement.
Cats: prepare a 1 microgram/ml concentration:
1. For 50 or 60 ml syringe, mix 0.1 ml dexmedetomidine (0.5 mg/ml) with 49.9 ml of sodium chloride 9 mg/ml (0.9 %) solution or Ringer’s lactate solution, yielding a final volume of 50 ml.
2. For 100 ml sodium chloride bottle, replace 0.2 ml of sodium chloride solution with 0.2 ml of dexmedetomidine (0.5 mg/ml).
Administer 0.5 ml/kg/h of this dilution for 0.5 microgram/kg/h or 1 ml/kg/h for 1 microgram/kg/h dose rates. For higher CRI rates (2–3 micrograms/kg/h), a stronger dilution (e.g. 3 micrograms/ml) may be prepared to keep infusion rates below typical maintenance fluid rates.
Symptoms of overdose (and where applicable, emergency procedures and antidotes)
Dogs: In cases of overdosage, or if the effects of dexmedetomidine become potentially life-threatening, the appropriate dose of atipamezole is 10 times the initial dose of dexmedetomidine (µg/kg bw or µg/square meter body surface area). The dose volume of atipamezole at the concentration of 5 mg/ml equals the dose volume of Dexdomitor that was given to the dog, regardless of route of administration of Dexdomitor.
Cats: In cases of overdosage, or if the effects of dexmedetomidine become potentially life-threatening, the appropriate antagonist is atipamezole, administered by intramuscular injection, at the following dose: 5 times the initial dose dexmedetomidine in µg/kg bw.
After concurrent exposure to a triple (3X) overdose of dexmedetomidine and 15 mg ketamine/ kg, atipamezole can be administered at the recommended dose level for reversal of effects induced by dexmedetomidine. At high serum concentrations of dexmedetomidine sedation is not increased although the level of analgesia does increase with further dose increases. The dose volume of atipamezole at the concentration of 5 mg/ml equals one-half the volume of Dexdomitor that was given to the cat.
In the event of signs of overdose when dexmedetomidine is administered as CRI, the infusion rate should be reduced or terminated. Oxygen should be supplemented as needed. Administration of atipamezole during general anaesthesia has not been evaluated.
Special restrictions for use and special conditions for use, including restrictions on the use of antimicrobial and antiparasitic veterinary medicinal products in order to limit the risk of development of resistance
Not applicable.
Withdrawal periods
Not applicable.