• ZooPharm
  • ZooPharm
  • ZooPharm
  • ZooPharm
Etorphine HCI (M99) 10ml - 10mg/ml

Etorphine HCI (M99) 10ml - 10mg/ml

Category: ZOO ANIMALS

Etorphine was the first potent opiate agonist employed primarily for use in non-domestic and wild species. Prior to its development and registration in the early 1960s, the only immobilization tools available were succinylcholine, nicotine sulphate, and ropes.

 

General Information and History

Etorphine revolutionized the ability of biologists and veterinarians to safely capture and restrain many species that previously could not be handled. Its reversibility with diprenorphine (M5050), a potent opiate antagonist, made it a significant advance in zoo and wildlife medicine. Etorphine hydrochloride was registered in the United States under the trade name of M99 by American Cyanamid. It was later registered in combination with acepromazine under the trade name of Immobilon in the United Kingdom. It is currently registered and available in South Africa under the trade name Captivon.

By virtue of its long history in veterinary medicine and wildlife biology, etorphine use in numerous species is well documented in the literature. Although newer and more desirable opiates have been developed (carfentanil, A3080), etorphine is still the drug of choice for exotic equids, rhino, and other hoof stock.

 

Use in Wildlife Management

Etorphine’s potent opiate agonist activity produces rapid reversible immobilization at low dose rates. It is routinely combined with azaperone, xylazine, or medetomidine. It is rapidly reversed with naltrexone or diprenorphine.

 

Etorphine has been used in almost every wild and free-ranging group with the exception of members of the family Felidae which have severe and adverse reactions to all opiate agonists. In the United States, it has been extensively used in feral horses, deer, elk, bison and, to some extent, in bear in years past. Its availability in the late 1960s concurrent with the development of reliable dart delivery systems allowed wildlife managers and researchers to conduct projects and studies that previously were impossible In zoological collections it has been used in elephant, rhino and members of the family Equidae. Its use in other species in zoos has been replaced by carfentanil, medetomidine combinations, and Telazol in combination with alpha-two agonists (xylazine, medetomidine).

 

Use in Domestic Species

Etorphine has had limited use in domestic species in the United States due to its high opiate agonist potency and the level of DEA control on this substance.

 

Pharmacology and Chemistry

Etorphine is a full opiate agonist and binds to multiple opiate sites in the central nervous system. It is believed to produce its clinical effects through binding the µ-, δ-, and κ- opiate sites. It has a potent effect on depressing the respiratory centers of the CNS thus resulting in apnea being commonly seen in immobilized animals.

 

Etorphine is chemically related to morphine. In laboratory animals, etorphine resembles morphine by causing analgesia, catatonia, blockade of conditional reflexes, and anti-diuretic effect. It also resembles morphine by causing excitement in mice, cats and bradycardia and hypotension in rats, dogs, cats and monkeys. When given subcutane- ously, etorphine is 1000-4000 times more potent than morphine as an analgesic, depending on the test situation. Its use for immobilizing game animals results largely from its ability to cause catatonia at very low dose levels.

 

The chemical name for etorphine hydrochloride is 6,14-Ethenomorphinan-7-methanol, 4,5-epoxy-3-hydroxy-6-methoxy-ά,17-dimethyl-ά-propyl-, (5ά,7á-(R))- hydrochloride.

 

Pharmacokinetics

The information available from pharmacokinetic studies with etorphine in target species is very scant. It is believed that the pharmacokinetic pathways and distribution of etorphine are not dissimilar to those of the other morphine base agonists.

 

CONTRAINDICATIONS AND PRECAUTIONS

Do not use Etorphine hydrochloride unless antidote or antagonist is on hand.

 

WARNING:

Adequate amount of a reversal agent, i.e. Naltrexone hydrochloride or Dipren- orphine (M5050) should be immediately available. Diprenorphine should never be used to antagonize etorphine in humans. Either naloxone (Narcan) or naltrexone should be used in the event of accidental human exposure.

 

RECOMMENDED DOSE RANGE

The literature regarding effective doses of etorphine in non-domestic species are extensive and beyond this monograph to list. General guidelines in the literature give the following dose rates applicable to North American species.

 

  Feral Equidae 0.44 mg per 100 lbs
  Ursidae 0.50 mg per 100 lbs
  Cervidae 0.98 mg per 100 lbs
  Bovidae 0.09 mg per 100 lbs


Doses and protocols for individual species are readily available in the published literature.



DOSE RATE FOR AFRICAN SPECIES

 

SPECIES

MASS KG

ETORPHINE

+ XYLAZINE

+ AZAPARONE

µg/kg

Total (mg)

µg/kg

Total (mg)

µg/kg

Total (mg)

African elephant

5000

1 – 1,25

5 – 15

-

-

-

-

Sq. Lipped Rhino

2000

1 – 2

2 – 3 3

-

-

125

250

Black Rhino

1000

2 – 4

2 – 4,5

-

-

250

250

Giraffe

1000

2 – 10 2

2 – 10

30 – 50

30 – 50

50 – 150

50 – 150

African Buffalo

700

7,5 – 15

5 – 12,5

50 – 100

35 – 70

50 – 150

35 – 105

Eland

700

7,5 – 15

5 – 10,5

100 – 300

70 – 210

100 – 200

70 – 140

Blue Wildebeest

200

10 – 20

2 – 4

50 – 100

10 – 20

150 – 300

30 – 60

Black Wildebeest

150

10 – 20

1,5 – 3

50 – 100

7,5 – 15

150 – 300

22,5 – 45

Red Hartebeest

140

15 – 25

2 – 3,5

50 – 100

7 – 14

150 – 300

21- 42

Lichtenstein Hartebeest

200

15 – 25

3 – 4

50 – 100

10 – 20

150 – 300

30 – 60

Tsessebe

140

15 – 25

2 – 3,5

75 – 150

10,5 – 21

150 – 300

21 – 42

Blesbok

90

15 – 25

1,5 – 2,5

50 – 100

4,5 – 9

150 – 300

13,5 – 27

Greater Kudu

250

15 – 25

4 – 8

50 – 100

12,5 – 25

150 – 300

37,5 – 75

Nyala

100

15 – 25

1,5 – 2,5

50 – 100

5 – 10

150 – 300

15 – 30

Bushbuck

50

15 – 25

1 – 1,5

50 – 100

2,5 – 5

150 – 300

7,5 – 15

Reedbuck

70

15 – 25

1 – 2

50 – 100

3,5 – 7

150 – 300

10,5 – 21

Waterbuck

250

15 – 25

4 – 8,5

75 – 150

18 – 36

150 – 300

37,5 – 75

Roan Antelope

280

15 – 25

4,2 – 7

50 – 100

15 – 30

150 – 300

45 – 90

Sable Antelope

240

15 – 25

3,6 – 6

50 – 100

12 – 24

150 – 300

35 – 72

Gemsbok

200

15 – 25

3 – 6,5

50 – 100

10 – 20

150 – 300

30 – 60

Impala

50

15 – 25

0,8 – 1,5

100 – 200

5 – 7,5

300 – 400

15 – 20

Springbok

35

15 – 25

0,5 – 1

100 – 200

3,5 – 5,3

300 – 450

10 – 15

Steenbok

12

15 – 25

0,2 – 0,3

100 – 200

1,2 – 2,4

300 – 450

4 – 6

Common Duiker

15

15 – 25

0,2 – 0,4

100 – 200

1,5 – 3

150 – 300

2,2 – 4,5

Zebra

250

15 – 25

4 – 6,5

400 – 500

100 – 150

300 – 500

90 – 150

Warthog

80

40 – 60

3 – 7

200 – 300

16 – 22

300 – 500

24 - 40

 

ADMINISTRATION

Inject dose deep into a large muscle mass of the neck, shoulder, back or hindquarter. Intrathoracic, intra-abdominal or subcutaneous injection is to be avoided. Etorphine is commonly administered in combination with alpha-two agonists (xylazine, medetom- idine). The alpha-two pharmacodynamics lessen the “opiate rigidity” commonly seen when etorphine is given alone.

 

FDA Approved Presentation for Etorphine hydrochloride

Etorphine (M99) is not currently commercially available due to lack of production by the manufacturer. Its approved form in South Africa is at the 4.9 and 9.8 mg/ml strengths (Captivon, Wildlife Pharmaceuticals South Africa, Karino). Availability of the Immobilon product in the United Kingdom is unknown at this time.

 

Compounded Forms Available

The concentrations compounded are 10 mg/ml in a 10 ml vial.

AddThis Social Bookmark Button