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Dosage and administration
An appropriately graduated syringe must be used to allow accurate administration of the required dose volume. This is particularly important when injecting small volumes. Medetomidine has marked anaesthetic sparing effects. It is essential to reduce the dose of induction and maintenance agents appropriately in animals that have been premedicated with Domitor.
DOGS
Domitor alone for canine sedation and analgesia
For parenteral use by intramuscular (IM), intravenous (IV) or subcutaneous (SC) injection.
Animal
Dose
micrograms/kg
Effect
Quantity
Dog
10 - 30
Slight
sedation
0.1 - 0.3 ml/
10 kg
Dog
30 - 80
Moderate
to deep
sedation and
analgesia
0.3 - 0.8 ml/
10 kg
Dog
10 - 20
Pre-
anaesthesia
0.1 - 0.2 ml/
10 kg
Maximal effect is obtained within 10 - 15 minutes. Duration of the clinically useful effect is dose-dependent (30 - 180 minutes). The dose can be repeated if necessary. Animals should be fasted for 12 hours prior to anaesthesia.
Domitor with butorphanol for canine sedation and analgesia
Medetomidine (Domitor) and butorphanol can be administered together in the same syringe, by IM or IV injection.
Dose rate: 10-25 mcg/kg medetomidine (0.01 - 0.025 ml/kg Domitor), depending on the degree of sedation required, plus 0.1mg/kg butorphanol (0.01ml/kg of 10mg/ml solution). Allow 20 minutes for sedation to develop before commencing the procedure.
Reversal with an equal volume of Antisedan IM to that of Domitor used results in sternal recumbency approximately 5 minutes later and standing approximately a further 2 minutes later.
Domitor with butorphanol followed by thiopentone anaesthesia
Dose rate: medetomidine 10 mcg/kg (0.01 ml/kg Domitor) and butorphanol 0.1mg/kg (0.01ml/kg of 10mg/ml solution).
Medetomidine and butorphanol can be administered together in the same syringe, by IM or IV injection.
Allow 20 minutes for sedation to develop before administering thiopentone.
Atipamezole (Antisedan) administered in the post-operative phase will hasten the recovery from anaesthesia.
Canine doses (ml) for mild sedation, or premedication prior to thiopentone, IM or IV:
Domitor 1mg/ml
butorphanol 10mg/ml
kg
10mcg/kg medetomidine
0.1 mg/kg
1
0.01
0.01
3
0.03
0.03
5
0.05
0.05
10
0.10
0.10
15
0.15
0.15
20
0.20
0.20
25
0.25
0.25
30
0.30
0.30
40
0.40
0.40
Canine doses (ml) for deep sedation:
Domitor 1mg/ml
butorphanol 10mg/ml
kg
25 mcg/kg medetomidine
0.1 mg/kg
1
0.03
0.01
3
0.075
0.03
5
0.13
0.05
10
0.25
0.10
15
0.38
0.15
20
0.50
0.20
25
0.63
0.25
30
0.75
0.30
40
1.00
0.40
Domitor as a premedicant before thiopentone in dogs, anaesthesia being maintained with halothane (with or without nitrous oxide)
Medetomidine (Domitor) is administered at least 20 minutes before thiopentone (induction agent) to allow sedation to develop. Domitor may be administered at a dose rate of 10, 20 or 40 mcg/kg. The table below is a guideline for doses, however, the dose of thiopentone required may vary considerably in individual animals. The optimum dose of Domitor is in the range of 20 - 40 mcg/kg and will depend on the temperament of the dog. At higher doses of medetomdine, thiopentone may not be required for intubation, i.e. intubation may be possible under medetomidine alone.
Medetomidine
Domitor
Thiopentone
Dose in
mcg/kg
Quantity in ml/10 kg
Dose in
mg/kg
ml/ 10kg of 2.5% solution
10
0.1
6.9
2.76
20
0.2
4.5
1.8
40
0.4
2.4
0.96
Thiopentone as a dilute solution (1.25 - 2.5%) is administered by the IV route slowly to effect over a period of 30 - 45 seconds. Once jaw relaxation is considered adequate, tracheal intubation can be undertaken.
N.B. Onset of unconsciousness may be delayed for up to one minute following injection of thiopentone. Therefore, slow IV injection is required as indicated above.
After intubation, anaesthesia may be maintained with halothane in oxygen (with or without nitrous oxide) administered to effect. Recovery from anaesthesia may take from 20 to over 60 minutes.
Food should be withheld for 12 hours prior to anaesthesia.
For recoveries in excess of one hour it is advisable to administer atipamezole (Antisedan).
Domitor as a premedicant before propofol in dogs.
Medetomidine (Domitor) is administered either IV at least 10 minutes before propofol (induction agent), or IM at least 20 minutes before propofol to allow sedation to develop. Medetomidine may be administered at a dose rate of 10, 20 or 40 mcg/kg (0.01, 0.02 or 0.04 ml/kg). The following table is a guideline for doses:
Medetomidine
Domitor
Propofol
Dose in mcg/kg
Quantity in ml/10 kg
Dose in mg/kg
Quantity in ml/10 kg of 10mg/ml emulsion
10
0.1
1.5
1.5
20
0.2
1.1
1.1
40
0.4
1.0
1.0
Following premedication with medetomidine, doses of propofol of up to 4 mg/kg (e.g. 0.4ml/kg of 10mg/ml emulsion) have been safely used when a greater depth of anaesthesia is required.
N.B. The induction time is increased following Domitor premedication; propofol should be administered by slow IV injection and up to 2.5 minutes should be allowed before a further dose is given.
Once jaw relaxation is adequate, tracheal intubation can be undertaken. It is advisable to administer oxygen during anaesthesia. For maintenance of anaesthesia the dose of propofol is markedly reduced by medetomidine premedication. Infusion doses of 0.06 to 0.35 mg/kg/minute (e.g. 0.006 - 0.035ml/kg/minute of a 10mg/ml emulsion) will provide stable anaesthesia for dogs sedated with between 40 and 10 mcg/kg Domitor respectively. For intermittent bolus administration, a dose of 1 mg/kg (e.g. 0.1ml/kg of a 10mg/ml emulsion) at intervals of between 4 and 12 minutes will provide stable anaesthesia.
Recovery from anaesthesia may take from 20 to greater than 60 minutes.
Food should be withheld for 12 hours prior to anaesthesia.
Atipamezole (Antisedan) administered in the post-operative phase will hasten the recovery from anaesthesia.
CATS
Domitor alone for feline sedation
For parenteral use by IM or SC injection.
Animal
Dose mcg/kg
Effect
Quantity
Cat
50 - 100
Moderate sedation
0.25 - 0.50 ml/5 kg
Cat
100 - 150
Deep sedation
0.50 - 0.75 ml/5 kg
Maximal effect is obtained within 10 - 15 minutes. Duration of the clinically useful effect is dose related (30 - 180 minutes). The dose can be repeated if necessary. Animals should be fasted for 12 hours prior to anaesthesia.
Domitor with butorphanol for feline sedation and analgesia
Medetomidine (Domitor) and butorphanol can be administered together in the same syringe, by IM or SC injection.
Dose rate: Medetomidine 50 mcg/kg (0.05 ml/kg Domitor), depending on the degree of sedation required, plus 0.4mg/kg butorphanol (0.04ml/kg of 10mg/ml solution). Allow 20 minutes for sedation to develop before commencing the procedure.
Local anaesthetic infiltration should be used for wound suturing.
Reversal with half the volume of Antisedan to that of the previously administered Domitor results in sternal recumbency approximately 4 minutes later and standing approximately a further 2 minutes later. See table.
Feline doses (ml) for sedation with Domitor and butorphanol IM or SC:
Domitor 1mg/ml
butorphanol 10mg/ml
kg
50 mcg/kg medetomidine
0.4 mg/kg
1
0.05
0.04
1.5
0.08
0.06
2
0.10
0.08
2.5
0.13
0.10
3
0.15
0.12
3.5
0.18
0.14
4
0.20
0.16
4.5
0.23
0.18
5
0.25
0.20
Domitor with ketamine for feline anaesthesia
Medetomidine (Domitor) and ketamine are administered concomitantly, in the same syringe, by the IM route. To minimise the possibility of cross contamination, the vials of each product should have separate needles inserted for withdrawal. Medetomidine should be administered at a rate of 80 mcg/kg (0.08 ml/kg Domitor) with a concomitant dose of 2.5 - 7.5 mg/kg ketamine (0.025 - 0.075ml/kg of 100mg/ml solution). Atropine is not normally necessary when using a medetomidine/ketamine combination.
Using this regime the average onset of anaesthesia is 3 - 4 minutes and surgical anaesthesia can be expected to last between 30 and 50 minutes. If required, anaesthesia may be prolonged with halothane and oxygen with or without nitrous oxide.
Food should be withheld for 12 hours prior to anaesthesia.
Domitor, butorphanol and ketamine for feline anaesthesia
a) IM
Dosage: Medetomidine 80 mcg/kg (0.08ml/kg Domitor), butorphanol 0.4mg/kg (0.04ml/kg of 10mg/ml solution) and ketamine 5mg/kg (0.05ml/kg of 100mg/ml solution) should be given in a single syringe
Cats become recumbent in 2-3 minutes following injection. Loss of the pedal reflex occurs 3 minutes post injection.
Reversal with atipamezole 200 mcg/kg ( 0.04 ml/kg Antisedan) results in return of the pedal reflex 2 minutes later, sternal recumbency 6 minutes later and standing 31 minutes later.
Feline doses (ml) for IM Domitor/butorphanol/ketamine anaesthesia:
Domitor 1mg/ml
butorphanol 10mg/ml
ketamine 100 mg/ml
kg
80 mcg/kg medetomidine
0.4 mg/kg
5mg/kg
1.5
0.12
0.06
0.075
2
0.16
0.08
0.10
2.5
0.20
0.10
0.125
3
0.24
0.12
0.15
3.5
0.28
0.14
0.175
4
0.32
0.16
0.20
4.5
0.36
0.18
0.225
5
0.40
0.20
0.25
b) IV
Dosage: Medetomidine 40 mcg/kg (0.04 ml/kg Domitor), butorphanol 0.1 mg/kg (e.g. 0.01ml/kg of 10mg/ml solution) and ketamine from 1.25 to 2.5 mg/kg, depending on the depth of anaesthesia required (e.g. 0.0125 - 0.025 ml/kg of 100mg/ml solution).
Reversal with atipamezole 100 mcg/kg ( 0.02 ml/kg Antisedan) by IM injection results in return of the pedal reflex 4 minutes later, sternal recumbency 7 minutes later and standing 18 minutes later. See table below
Feline doses (ml) for IV Domitor/butorphanol/ketamine anaesthesia:
Domitor 1mg/ml
butorphanol 10mg/ml
ketamine 100 mg/ml
ketamine 100 mg/ml
kg
40 mcg/kg medetomdine
0.1 mg/kg
Minimum
1.25 mg/kg
Maximum
2.5 mg/kg
1.5
0.06
0.02
0.02
0.04
2
0.08
0.02
0.03
0.05
2.5
0.10
0.03
0.03
0.06
3
0.12
0.03
0.04
0.08
3.5
0.14
0.04
0.04
0.09
4
0.16
0.04
0.05
0.10
4.5
0.18
0.05
0.06
0.11
5
0.20
0.05
0.06
0.13
Approximate time scales in IV Domitor / butorphanol / ketamine anaesthesia:
Ketamine dose
1.25 mg/kg
2.5 mg/kg
Time to recumbency
32 secs
22 secs
Time to loss of pedal reflex
62 secs
39 secs
Time to return of pedal reflex
26 mins
28 mins
Time to sternal recumbency
54 mins
62 mins
Time to standing
74 mins
83 mins
Domitor followed by alphaxalone/alphadolone for feline general anaesthesia
Dosage: Administer medetomidine 80 mcg/kg (0.08ml/kg Domitor) by IM or SC injection.
15 - 60 minutes later administer 2.5 - 5.0 mg/kg alphaxalone/alphadolone ( e.g. 0.208 - 0.416 ml/kg of a 12mg/ml solution) IV.
Anaesthesia may be maintained by further IV injections of alphaxalone/alphadolone, or by administration of halothane in oxygen.
Feline doses (ml) for Domitor( IM or SC) plus alphaxalone/alphadolone (IV) anaesthesia:
Domitor 1mg/ml
alphaxalone 9mg/ml + alphadolone
3 mg/ml
alphaxalone 9mg/ml + alphadolone
3 mg/ml
kg
80 mcg/kg medetomidine
minimum dose
2.5 mg/kg
maximum dose
5 mg/kg
1
0.08
0.21
0.42
1.5
0.12
0.31
0.63
2
0.16
0.42
0.83
2.5
0.20
0.52
1.04
3
0.24
0.63
1.25
3.5
0.28
0.73
1.46
4
0.32
0.83
1.67
4.5
0.36
0.94
1.88
5
0.40
1.04
2.08