Alfaxan Multidose
Active substance
ATC code
Species
Dogs, cats and pet rabbits.
Indications
As an induction agent prior to inhalation anaesthesia in dogs, cats and pet rabbits.
As a sole anaesthetic agent for the induction and maintenance of anaesthesia for the performance of examination or surgical procedures in dogs and cats.
Dose to be administered and administration route
Dogs, cats and pet rabbits: For intravenous use (IV).
Induction of anaesthesia (dogs, cats and pet rabbits):
The induction dose of the veterinary medicinal product is based on data taken from controlled laboratory and field studies and is the amount of drug required for 9 of 10 patients (i.e. 90th percentile) to be successfully induced for anaesthesia.
Dosing recommendations for induction of anaesthesia are as follows:
|
DOGS |
CATS |
PET RABBITS |
||||
|
Unpremedicated |
Premedicated |
Unpremedicated |
Premedicated |
Unpremedicated |
Premedicated |
|
|
mg/kg |
3 |
2 |
5 |
5 |
5 |
4 |
|
ml/kg |
0.3 |
0.2 |
0.5 |
0.5 |
0.5 |
0.4 |
In dogs, cats and rabbits, an intravenous catheter should be used to administer the veterinary medicinal product (please refer to sections 3.5 and 3.6).
The dosing syringe should be prepared to contain the above dose. Administration should continue until the clinician is satisfied that the depth of anaesthesia is sufficient for endotracheal intubation, or until the entire dose has been administered. The necessary injection rate can be achieved by administration of one quarter (¼) of the calculated dose every 15 seconds, so that the total dose, if required, would be administered over the first 60 seconds. If, 60 seconds after complete delivery of this first induction dose, intubation is still not possible, one further similar dose may be administered to effect.
Maintenance of anaesthesia (dogs and cats):
Following induction of anaesthesia with the veterinary medicinal product, the animal may be intubated and maintained on the veterinary medicinal product or an inhalation anaesthetic agent. Maintenance doses of the veterinary medicinal product may be given as supplemental boluses or as constant rate infusion. The veterinary medicinal product has been used safely and effectively in dogs and cats for procedures lasting for up to one hour. The following doses suggested for maintenance of anaesthesia are based on data taken from controlled laboratory and field studies and represent the average amount of drug required to provide maintenance anaesthesia for a dog or cat. However, the actual dose will be based on the response of the individual patient.
Dosing recommendations for maintenance of anaesthesia are as follows:
|
DOGS |
CATS |
|||
|
Unpremedicated |
Premedicated |
Unpremedicated |
Premedicated |
|
|
Dose for constant rate infusion |
||||
|
mg/kg/hour |
8 - 9 |
6 - 7 |
10 - 11 |
7 - 8 |
|
mg/kg/minute |
0.13 - 0.15 |
0.10 - 0.12 |
0.16 - 0.18 |
0.11 - 0.13 |
|
ml/kg/minute |
0.013 - 0.015 |
0.010 - 0.012 |
0.016 - 0.018 |
0.011 - 0.013 |
|
Bolus dose for each 10 minutes maintenance |
||||
|
mg/kg |
1.3 - 1.5 |
1.0 - 1.2 |
1.6 - 1.8 |
1.1 - 1.3 |
|
ml/kg |
0.13 - 0.15 |
0.10 - 0.12 |
0.16 - 0.18 |
0.11 - 0.13 |
Where maintenance of anaesthesia is with the veterinary medicinal product for procedures lasting more than 5 to 10 minutes, a butterfly needle or catheter can be left in the vein, and small amounts of the veterinary medicinal product injected subsequently to maintain the required level and duration of anaesthesia. In most cases the average duration of recovery when using the veterinary medicinal product for maintenance will be longer than if using an inhalant gas as a maintenance agent.
Adverse reactions
Dogs and cats:
|
Very common (>1 animal / 10 animals treated) |
Apnoea1 |
|
Very rare (<1 animal / 10,000 animals treated, including isolated reports) |
Hyperactivity, vocalisation; Bradycardia, cardiac arrest; Convulsion, myoclonus, prolonged anaesthesia, tremor; Bradypnoea |
1Observed post induction. 44% of dogs and 19% of cats experienced post induction apnoea in clinical studies; the mean duration of apnoea in these animals was 100 seconds in dogs and 60 seconds in cats. Endotracheal intubation and oxygen supplementation should therefore be employed.
Pet rabbits:
|
Common (1 to 10 animals / 100 animals treated) |
Behavioural disorder1,2, head shake2; Ear flapping/twitching2; Apnoea3 |
1 Manifested as backing away.
2During intravenous (marginal ear vein) administration and, therefore, administration of the veterinary medicinal product via a pre-placed catheter in the marginal ear vein is recommended. Premedication may also prevent these reactions. In a field study, these reactions were not observed when rabbits had been premedicated with medetomidine in combination with either butorphanol or buprenorphine.
3Observed post-induction. The mean duration of apnoea in these animals was 53 seconds.
Endotracheal intubation and oxygen supplementation should therefore be employed.
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 the national competent authority via the national reporting system. See package leaflet for respective contact details.
