Target species
Dogs and cats.
Indications for use for each target species
In dogs and cats:
Sedation to facilitate handling. Premedication prior to general anaesthesia.
In cats:
In combination with ketamine for general anaesthesia for minor surgical procedures of short duration.
Contraindications
Do not use in animals with:
- Severe cardiovascular disease or respiratory diseases or impaired liver or kidney function.
- Mechanical disturbances of the gastro-intestinal tract (torsio ventriculi, incarcerations,
oesophageal obstructions).
- Diabetes mellitus.
- State of shock, emaciation or serious debilitation.
Do not use concomitantly with sympathomimetic amines.
Do not use in cases of hypersensitivity to the active substance or to any other excipients.
Do not use in animals with ocular problems where an increase in intraocular pressure would be detrimental.
See also section "Use during pregnancy, lactation or lay".
Special warnings
Medetomidine may not provide analgesia throughout the entire period of sedation, therefore consideration should be given to providing additional analgesia for painful procedures.
Special precautions for use
Special precautions for safe use in the target species:
A clinical examination should be carried out in all animals before the use of veterinary medicinal products for sedation and/or general anaesthesia. Higher doses of medetomidine should be avoided in large breed dogs. Care should be taken when combining medetomidine with other anaesthetics or sedatives (e.g. ketamine, thiopental, propofol, halothane), because of its marked anaesthetic sparing effects. The dose of the anaesthetic should be reduced accordingly and titrated to response due to considerable variability in requirements between patients. Before using any combinations, the warnings and contra-indications in the product literature for the other products should be observed.
Animals should be fasted 12 hours before anaesthesia.
The animal should be placed in a calm and quiet surrounding to let the sedation gain its maximum effect.
This takes about 10 – 15 minutes. One should not start any procedure or give other medicines before maximum sedation is reached.
Treated animals should be kept warm and at a constant temperature, both during the procedure and recovery. The eyes should be protected by a suitable lubricant.
Nervous, aggressive or excited animals should be allowed to calm down before initiation of treatment.
Sick and debilitated dogs and cats should only be premedicated with medetomidine before induction and maintenance of general anaesthesia based on a risk-benefit assessment.
Care should be taken with use of medetomidine in animals with cardiovascular disease, or which are elderly or in general poor health. Liver and kidney function should be evaluated prior to use.
Medetomidine may cause respiratory depression and under these circumstances, manual ventilation and oxygen may be administered.
To reduce the recovery time following anaesthesia or sedation the effect of the veterinary medicinal product can be reversed by administration of an alpha-2 antagonist e.g. atipamezole or yohimbine. As ketamine alone can elicit cramps, alpha-2 antagonists should be administered not before 30-40 min. after ketamine. For dosage directions, see section "Administration routes and dosage".
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 label to the physician but DO NOT DRIVE as sedation and changes in blood pressure may occur.
Care should be taken to avoid accidental self-injection, as well as contact with the skin, eyes and mouth.
Wash the exposed skin immediately after exposure with large amounts of water.
Remove contaminated clothes that are in direct contact with skin.
In the case of accidental contact of the product with eyes, 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.
To the physician: Medetomidine is an alpha2-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.
Special precautions for the protection of the environment:
Not applicable.
Adverse events
Dogs and cats:
Common (1 to 10 animals / 100 animals treated): | Bradycardia, Heart block 1st degree, Heart block 2nd degree, Extrasystole, Vasoconstriction of coronary artery, Cardiac depression1, High blood pressure2 Bradypnoea |
Uncommon (1 to 10 animals / 1,000 animals treated): | Emesis3. Increased sensitivity to sound, Muscle tremor Increased urine volume4 Hypothermia, Cyanosis Respiratory depression Injection site pain |
Rare (1 to 10 animals / 10,000 animals treated): | Pulmonary oedema |
Very rare (<1 animal / 10,000 animals treated, including isolated reports): | Hyperglycaemia5 |
1 Decreased cardiac output. In circulatory and respiratory depression manual ventilation and an oxygen supplement may be indicated. Atropine may increase the cardiac rate.
2 Blood pressure will increase initially after administration and then return to normal, or slightly below normal.
3 Particularly in cats. This occurs within a few minutes of administration. Cats may also vomit on recovery.
4 Due to increased diuresis.
5 Reversible. In individual cases, due to depression of insulin secretion.
Dogs with a body weight of less than 10 kg may show the undesirable effects mentioned above more often.
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
The safety of this veterinary medicinal product has not been established during pregnancy and lactation. Therefore it should not be used during pregnancy and lactation.
Interaction with other medicinal products and other forms of interaction
The concomitant use of other CNS depressants should be expected to potentiate the effect of either active substance. Appropriate dose adjustments should be made.
Medetomidine has marked anaesthetic sparing effects. See also section "Special precautions for use".
The effects of medetomidine may be antagonized by administration of atipamezole or yohimbine. See also section "Symptoms of overdose".
Do not use concomitantly with sympatomimetic amines or sulfamides + trimethoprim.
Administration routes and dosage
Dogs: Intramuscular or intravenous use.
Cats: Intramuscular and subcutaneous use.
Dogs:
For sedation the veterinary medicinal product should be administered at the rate of 750 µg medetomidine hydrochloride i.v. or 1000 µg medetomidine hydrochloride i.m. per square meter of body surface, corresponding to dose of 20-80 µg medetomidine hydrochloride per kg body weight.
Use the table below to determine the correct dosage on the basis of body weight:
Maximal effect is obtained within 15-20 minutes. Clinical effect is dose-dependent, lasting from 30 – 180 minutes.
Use of an appropriately graduated syringe is recommended to ensure accurate dosing when administering small volumes.
The veterinary medicinal product dosages for sedation in ml and corresponding amount of medetomidine hydrochloride in μg /kg bw. For pre-medication use 50% of the dose indicated in the table:
bodyweight (kg) | intravenous injection (ml) | corresponding to (μg/kg bw) | intramuscular injection (ml) | corresponding to (μg/kg bw) |
1 | 0.08 | 80.0 | 0.10 | 100.0 |
2 | 0.12 | 60.0 | 0.16 | 80.0 |
3 | 0.16 | 53.3 | 0.21 | 70.0 |
4 | 0.19 | 47.5 | 0.25 | 62.5 |
5 | 0.22 | 44.0 | 0.30 | 60.0 |
6 | 0.25 | 41.7 | 0.33 | 55.0 |
7 | 0.28 | 40.0 | 0.37 | 52.9 |
8 | 0.30 | 37.5 | 0.40 | 50.0 |
9 | 0.33 | 36.7 | 0.44 | 48.9 |
10 | 0.35 | 35.0 | 0.47 | 47.0 |
12 | 0.40 | 33.3 | 0.53 | 44.2 |
14 | 0.44 | 31.4 | 0.59 | 42.1 |
16 | 0.48 | 30.0 | 0.64 | 40.0 |
18 | 0.52 | 28.9 | 0.69 | 38.3 |
20 | 0.56 | 28.0 | 0.74 | 37.0 |
25 | 0.65 | 26.0 | 0.86 | 34.4 |
30 | 0.73 | 24.3 | 0.98 | 32.7 |
35 | 0.81 | 23.1 | 1.08 | 30.9 |
40 | 0.89 | 22.2 | 1.18 | 29.5 |
50 | 1.03 | 20.6 | 1.37 | 27.4 |
60 | 1.16 | 19.3 | 1.55 | 25.8 |
70 | 1.29 | 18.4 | 1.72 | 24.6 |
80 | 1.41 | 17.6 | 1.88 | 23.5 |
90 | 1.52 | 16.9 | 2.03 | 22.6 |
100 | 1.63 | 16.3 | 2.18 | 21.8 |
For premedication the veterinary medicinal product should be administered at a dosage of 10-40 µg medetomidine hydrochloride per kg body weight, corresponding to 0.1-0.4 ml Dorbene vet 1 mg/ml per 10 kg body weight. The exact dose depends on the combination of drugs used and the dosage(s) of the other drug(s). The dose should furthermore be adjusted to the type of surgery, length of procedure and patient temperament and weight. Premedication with medetomidine will significantly reduce the dosage of the induction agent required and will reduce volatile anaesthetic requirements for maintenance anaesthesia. All anaesthetic agents used for induction or maintenance of anaesthesia should be administered to effect. Before using any combinations, product literature for the other products should be observed. See also section "Special precautions for use".
Cats:
For moderate-deep sedation and restraint of cats the veterinary medicinal product should be administered at a dosage of 50 – 150 µg medetomidine hydrochloride /kg bw (corresp. to 0.05 – 0.15 ml veterinary medicinal product / kg bw). The speed of induction is slower when subcutaneous route of administration is used.
For anaesthesia the veterinary medicinal product should be administered at a dosage of 80 µg medetomidine hydrochloride / kg bw (corresp. to 0.08 ml veterinary medicinal product / kg bw) and 2.5 to 7.5 mg ketamine / kg bw. Using this dosage anaesthesia occurs within 3 – 4 minutes and is apparent for 20 – 50 minutes. For longer lasting procedures administration has to be repeated by using ½ of the initial dose (i.e. 40 µg medetomidine hydrochloride (corresp. to 0.04 ml veterinary medicinal product / kg bw) and 2.5 - 3.75 mg ketamine / kg bw) or 3.0 mg ketamine / kg bw alone. Alternatively, for longer lasting procedures anaesthesia may be extended by use of the inhalation agents isoflurane or halothane, with oxygen or oxygen/nitrous oxide. See section "Special precautions for use".
Symptoms of overdose (and where applicable, emergency procedures and antidotes)
Overdose will cause delayed recovery after sedation or anaesthesia. In some cases circulatory or respiratory depression may also occur. For treatment of these cardio-respiratory effects of an overdose it is recommended to administer an alpha-2 antagonist e.g. atipamezole or yohimbine, provided that reversal of sedation is not dangerous to the patient (atipamezole does not reverse the effects of ketamine which may cause seizures in dogs and elicit cramps in cats when used alone). Alpha-2 antagonists should be administered not before 30-40 min. after ketamine. In dogs, the dose of atipamezole is 5 times that for medetomidine. For example, if 1ml veterinary medicinal product (1mg medetomidine) has been administered, a dose of 5 mg atipamezole is required. In cats, the dose of atipamezole is 2.5 times that for medetomidine. For example, if 1 ml veterinary medicinal product (1 mg medetomidine) has been administered, a dose of 2.5 mg atipamezole is required.
If it is imperative to reverse bradycardia but maintain sedation, atropine may be used.
In cases of delayed recovery, care should be taken to ensure that the animal remains quiet and warm.
Depending on the situation, the animal may also be ventilated with oxygen and receive intravenous fluids to prevent hypovolaemia. The maintenance of body temperature during sedation and recovery is especially important; in cases of hypothermia, increasing the body to temperature to the normal level for the particular species will hasten recovery.
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.