March 25, 2007

Etorphine Hydrochloride

Just ran into this stuff today (the write-up, not the actual chemical). Holy crap does it ever sound dangerous. Check out: Etorphine Hydrochloride
Technical Information
M99 (Etorphine)

M99 (etorphine hydrochloride) was synthesised by Bentley & Hardy (1963) and is chemically related to morphine. When given subcutaneously, M99 is 1,000 to 80,000 times more potent than morphine as an analgesic. Its use for immobilising game animals results largely from its ability to cause catatonia at very low dose levels (for example, the total dose for a rhino may be as low as 5 mg). Because of the great risk involved to man and animal in handling this substance, the possession and use of M99 is strictly controlled by law in almost all countries. Novartis enforces this and ensures that M99 and M5050 is only supplied to registered veterinarians.

The approved generic name of this compound is etorphine hydrochloride, and the chemical name is 6,14-endoetheno – 7 a (1-(R)-hydroxy-1 methylbutyl)-tetrahydro-nororipavine hydrochloride.

M99 is chemically related to morphine. This compound was synthesised by Bentley & Hardy (1963). The acute pharmacology was described in detail by Blane, Bora, Fitzgerald and Lister (1967). In laboratory animals M99 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 subcutaneously M99 is 1,000 - 80,000 times more potent than morphine as an analgesic, depending on the test situation. Its use for immobilising game animals results largely from its ability to cause catatonia at very low dose levels.

M5050
The approved generic name for this compound is diprenorphine, and the chemical name is N-cyclopropylmethyl-6, 14-endoetheno-7-(1-hydroxy-1-methylethyl)tetrahydro-nororipavine. It is a potent morphine antagonist with an action similar to nalorphine. Its potency, however, was stated by Bentley et al. (1965) to be up to 35 times greater than nalorphine and to have a duration of action two to three times as long. In game animals it produced a rapid and complete reversal of the immobilisation produced by M99. Although it appears that there may be some degree of species variation in the response in practice it has been found that a dosage ratio M5050 to M99 of 1:1 is perfectly satisfactory i.e. 1.3mg diprenorphine produces reversal of the immobilising action of 1mg etorphine.
5mg is enough to immobilize a rhino? Yikes! Check out the required handling procedure:
Safety Precautions
  1. Keep M99 and M5050 together.
  2. Ensure that there is sufficient M5050 to reverse the effects of M99.
  3. Load the M5050 syringe first and keep it to hand throughout the procedure.
  4. Load the M99 syringe well clear of the patient or assisting persons.
  5. Use a disposable syringe.
  6. Discard empty M99/M5050 vials - never reuse containers for other drugs.
  7. Always ensure that a syringe loaded with an appropriate antidote for human use is at hand (Narcan).
  8. DON’T confuse different preparations.
  9. DON’T use a syringe that has previously been used for M99 or any other drugs.
  10. DON’T carry a syringe loaded with M99 in your pocket. Syringes loaded with M99 should carry a needle guard.

    Further advice on handling Large Animal M99
  11. Once the required dose of M99 has been withdrawn from the vial it is strongly recommended that the needle be removed from the syringe and discarded into a closed container. A sterile needle should then be inserted into the injection site and the syringe connected to it.
  12. Wear gloves.
  13. Do not pressurise the contents of the vial.
  14. An eye and skin wash should be made available.
  15. An assistant capable of giving an injection of reversing agent should be present whenever Large Animal M99 is used.
  16. The veterinary surgeon should fully brief the assistant on the procedure and indicate whether M5050 is to be considered as an antidote in the event of personal accident.
  17. To minimise risk of accident when injecting M99 i.v., the Portex Minivein or similar equipment can be used.
  18. Immobilise only one animal at a time and keep it under constant supervision at all stages. In cases of respiratory failure, inject M5050 immediately and maintain artificial ventilation.
Posted by DaveH at March 25, 2007 6:45 PM