Updates in Anesthesia

Indiana VMA February 2015

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Updates in Anesthesia and

Analgesia

James S. Gaynor, DVM, MS, DACVAA, DAAPM Breckenridge, CO USA 719-330-5608 www.PeakVets.com

Goals •  Identify newer approaches •  What makes them any better? •  What makes an older drug worse? •  Can I use them in a cost effective

manner next week? •  Should I discontinue their use?

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Current Concepts for Anesthesia and Analgesia

•  CONTROL •  Short acting •  Reversible

•  Need to abandon old concepts

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Propoflo28® •  28 day shelf life •  Good for most

anesthetic inductions

•  Greater # indications than diazepam / ketamine

•  Why not use it? Time to abandon made up shelf lives

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Propoflo28

•  Benzyl alcohol 20mg/ml

•  “may be toxic to cats”-?

•  Toxic dose 300-400 mg/kg

•  Approved for use in cats in the UK

•  Not a problem for routine use

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Now here…Alfaxalone

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Alfaxalone –Alfaxan® •  Not new •  Previously Saffan® = Alfaxalone +

alfadalone in cremophor – Histamine release – Anaphylaxis

•  Never approved in the US

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Progesterone

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Alfaxalone

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Neurosteroids Alfaxalone Progesterone

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Alfaxalone – Alfaxan® •  Neurosteroid •  Water soluble vs

prior formulation •  Solubilized in beta

cyclodextrin •  Rapid liver

metabolism

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Mechanism of action - GABA receptors

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Alfaxan® •  Rapid acting •  Short duration •  Minimal side

effects •  Similar to propofol

but little to no cardiovascular effects

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Alfaxan® •  Induction agent •  Repeat boluses •  Continuous

infusion •  Rapid recovery –

faster than propofol

•  Safely combined with premeds

Intramuscular- Fractious animals with minimal effects ©2015 PPVG

Alfaxan® SLOWLY to avoid adverse effects

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Alfaxan®- Systolic BP - dogs

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Alfaxan® Respiratory - Dog

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Alfaxalone vs Propofol •  Both are non-cumulative •  Less apnea and respiratory depression at

reasonable doses •  Less myoclonus without premed •  Wider dose range with good hemodynamics: BP,

CO •  Replacement for Etomidate •  Less delayed hypotension (cats > dogs) •  Higher APGAR scores post C-section in dogs •  Better for short term procedures withouf gas

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Alfaxan®- No drug is perfect •  Some improvement over propofol

•  Possible apnea- who cares?

•  Possible rough recovery with appropriate premedication

•  Cats are sensitive to stimulation ©2015 PPVG

Alfaxalone •  Neurosteroid •  IV/IM •  Canine / Feline •  Slow

administration •  Any benefit over

propofol?

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Butorphanol •  Kappa agonist- mu

antagonist •  Mild to moderate

analgesia: NEVER the same as mu agonist

•  45 minute duration in dogs 0.8 mg/kg

•  4 hr duration in cats

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Butorphanol •  Oral •  Dosing needs to

be 5x greater than IV

•  Cost effective?

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Buprenorphine •  Partial mu agonist -

antagonist •  Mild - moderate

analgesia •  NOT good for severe

pain •  Long duration 6-12

hrs •  Feline differences -

better analgesia? Pending changes in Feline Dosing?

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Buprenorphine •  Current dose

0.01-0.03 mg/kg

•  Possible new dose >0.2 mg/kg lasting 24 hrs

•  Based on objective data

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Buprenorphine –Changing worlds •  Partial mu agonist –

antagonist – Species specific

•  Mild - moderate analgesia

•  NOT good for severe pain

•  Long duration 6-12 hrs

•  Feline differences - better analgesia?

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Introducing the first and only FDA-Approved buprenorphine for surgical pain control in cats

SIM-2042 © Abbott Laboratories July 2014


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Features Benefits

•  Postoperative pain control day and night for the patient

•  FDA approved formulation based on extensive clinical efficacy and safety data in cats

Convenience of multidose vial for the clinic

•  One dose of SIMBADOL™ (buprenorphine injection) works for 24 hours

•  Proven efficacy and safety with over 200 cats treated with Simbadol

•  SIMBADOL is supplied in a 10 mL multidose vial that can be used for 28 days after the first puncture

•  Schedule III •  Concentration = 1.8 mg/mL •  21 month expiration dating •  28 day shelf life after first

puncture •  Approximately 15 doses per

vial

Simabdol

SIMBADOL™ (buprenorphine injection) Indication and Dosing

Indicated for the control of postoperative pain associated with surgical procedures in cats.

0.24 mg/kg (0.11 mg/lb) SQ once daily, for up to 3 days. Administer the first dose approximately 1 hour prior to surgery.

Buprenorphine SR

•  Weak clinical data

•  Pharmacokinetic data for dogs and cats

•  3 days •  If it was that

easy….. ©2015 PPVG

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Morphine •  Very inexpensive •  Premed 0.2-1.0 mg/kg SQ, IM •  Post-op 0.1-0.2 mg/kg/hr •  Relatively long lasting •  Most likely to cause vomiting as

premed

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Morphine and Cats •  Morphine – 6 –

glucuronide necessary for analgesia

•  Cats produce very little even when given IV

•  Sedation and dysphoria but analgesia?

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Methadone •  Similar potency as

morphine •  Similar dose as

morphine •  Virtually ZERO

vomiting •  NMDA antagonist •  Feline EUPHORIA

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Methadone •  Dogs •  0.5-1.0 mg/kg SQ,

IM •  0.1 - 0.25 mg/kg IV

•  Cats •  0.25 mg/kg SQ, IM

•  0.05-0.1 mg/kg IV

•  BUCCAL 0.1-.2 mg/kg Q 4-8 hrs

•  Oral 1 mg/kg Q 8-12 hrs

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Nalbuphine •  Kappa agonist / mu

antagonist •  Equivalent or

better analgesic than butorphanol

•  Usable in all species

•  Last longer •  No sedation by

itself ©2015 PPVG

0.1-0.5 mg/kg SQ, IM, IV ©2015 PPVG

Fentanyl Patches •  Theoretical

efficacy •  Good data in

multiple species •  Must maintain

good patch adherance

•  Clinical effectiveness?

84% of clinical dogs have sub-therapeutic plasma levels


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Tramadol •  Opioid like •  mu agonist effects •  Good for mild –

moderate pain •  Best with an NSAID •  2-4 mg/kg PO BID-QID •  Compound in something

sweet for cats

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Transdermal Fentanyl Solution •  96 hr duration •  Postoperative pain

in dogs •  Apply 2-4 hrs prior

to sx

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INDICATION: RECUVYRA is indicated for the control of postoperative pain associated with surgical procedures in dogs

WARNING: Abuse Potential: RECUVYRA contains fentanyl, a high concentration µ-opioid receptor agonist (50 mg/mL) and is a Class II controlled substance with high potential for abuse. Risk Minimization and Action Plan: This product is distributed under a Risk Minimization Action Plan (RiskMAP) and its use is limited to certified veterinarians. Human Safety: SECONDARY EXPOSURE TO FENTANYL IN CHILDREN AND ADULTS: Strict adherence to the requirements of the RiskMAP and the INSTRUCTIONS FOR USE provided in this product insert is imperative in order to reduce the potential of secondary exposure to fentanyl from RECUVYRA treated skin. Animal Safety: Individual dogs may be especially sensitive to the effects of fentanyl. See Contraindications, Warnings: Human and Animal Safety, and Precautions for detailed information.

Before using this product, it is important to read the entire product insert. The following is an excerpt from the Boxed Warning which highlights important safety information.

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Unique Delivery -Medistend™ 1.  Solution is applied to the skin 2.  Volatile liquid (alcohol) rapidly evaporates 3.  Penetration enhancer (octyl salicylate) &

active ingredient (fentanyl) become supersaturated

4.  Active ingredient is driven into the skin (stratum corneum) by concentration gradient

5.  Once in the skin, a slow rate of active ingredient is delivered into the bloodstream

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Solution is applied to the skin

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Volatile liquid (alcohol) rapidly evaporates

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Penetration enhancer and active fentanyl become supersaturated

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Active ingredient is driven into the skin (stratum corneum)

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Once in the skin, a slow rate of active ingredient is delivered into the bloodstream

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Recuvyra® Uses – Dogs •  OHE •  Stable trauma

patients •  Routine

orthopedics •  ASA I, II

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Recuvyra® Uses- Cats •  Do NOT use in cats •  Different absorption •  Huge doses •  Dysphoria •  Mania

•  Remember MORPHINE MANIA?

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Recuvyra® (Transdermal fentanyl solution) Issues

•  Sedation!!!! –  Reversible with

naloxone and nalbuphine

–  Prevent by adjusting dose based on expected pain

•  Integration into anesthesia –  Do what you do –  Pure mu agonists

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Don’t Forget to Try the On Line Consultation Service

50% off for 1 month

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Further Information

For Consultation

719-330-5608 www.PeakVets.com

©2015 PPVG

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