M thru O


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a)      Classification

i)        Alpha-2 agonist

b)      General Information

i)        Potent sedative/analgesic

ii)       Moderately long duration of effect (4 - 6 hours)

c)      Advantages/Recommended use

i)        Best reserved for young healthy patients needing a reversible agent

ii)       Significant reduction in induction agent and lower MAC of inhalants

(1)   Thiopental need may drop to 0.5 mg/lb or less

iii)     10 times more selective for alpha-2 vs. alpha-1 than xylazine

iv)     Can be used with ketamine and butorphanol as an IM anesthetic protocol for short procedures in cats

d)      Cautionary Information


      (1) Label doses are as high as 0.080 mg/kg at smaller patient size

ii)   Do not use in debilitated or cardiovascularly unstable patients

iii)     Extremely stressed patients may not respond as well

(1)   Isolate in quiet, dark room if possible to facilitate effect

iv)     May cause dramatic bradycardia

(1)   This can rarely be a an unresponsive, fatal bradycardia

(2)   Anticholinergic use is not routinely recommended

(a)    Anticholinergic need is best determined by monitoring patient blood pressures

v)      Alpha-2 agonists depress insulin production

(1)   Use with caution or avoid in non-insulin dependent diabetics

e)      Dosage Information

i)        Dog & Cats

(1)   0.002 to 0.030 mg/kg (0.001 to 0.015 mg/lb) IV, IM, SC

(2)   0.005 to 0.020 mg/kg (0.0025 to 0.010 mg/lb) is usually very adequate for dogs and cats when combined with an opioid like butorphanol

ii)       IM protocol for cats

(1)   (25 ug/kg Medetomidine, 5 mg/kg Ketamine, 0.2 mg/kg Butorphanol)

(a)    For larger cats, consider lean body mass equivalent weight

(b)   Consider insulin syringes especially for smaller cats

(2)   IV catheters are still highly recommended

(3)   Intubation is highly recommended

(a)    Allows the easy addition of inhalant anesthetic agent should the patient be inadequately anesthetized for longer procedures

f)       Cost

i)        High (especially if atipamazole is used)


a)      Classification

i)        A COX2 selective NSAID

b)      General Information

i)        Effective anti-inflammatory/analgesic generally free of significant GI side effects

ii)   The oral suspension is available in 1.5 mg/ml and 0.5 mg/ml concentrations

iii)  The injectable product is a 5 mg/ml concentration

c)      Advantages/Recommended use

i)        Short term use for acute pain

ii)       Long term use in chronic pain for tolerant patients

(1)   This NSAID appears more suitable for longer term use in cats

(a)    Cats, even more so than dogs, need to be monitored closely during therapy

d)      Cautionary Information

i)        As with any NSAID, GI side-effects can be substantial

(1)   Discontinue use if GI signs develop

ii)       Avoid use in:

(1)    Combination with corticosteroids

(a)    Potentially increased ulcerogenic effect

(2)   Renal compromised patients, dehydrated or hypotensive patients, patients with hepatic disease, pregnancy, patients with pre-existing GI disease, coagulopathies

iii)     Monitor liver enzymes of canine patients on chronic therapy

e)      Dosage Information

i)        Dogs

      (1)  0.2 mg/kg (0.1 mg/lb) IV, SC, PO SID on day one then 0.1 mg/kg (0.05 mg/lb) IV, SC, PO SID

ii)       Cats

(1)   Acute perioperative pain: 0.1 mg/kg to 0.2 mg/kg (0.05 to 0.1 mg/lb) SC, PO followed by 0.05 mg/kg (0.025 mg/lb) for up to 4 days if needed

(2)  Chronic pain: 

(a)    0.1 mg/kg (0.05 mg/lb) SC, PO on day 1, followed by 0.05 mg/kg (0.025 mg/lb) for up to 4 days, then reduce to lowest effective dose (0.025 mg/kg PO once every 48 to 72 hours) if long term use is required (Lascelles 2007)

(b)    0.05 mg/kg (0.025 mg/lb) SC, PO on day 1, followed by 0.025 mg/kg (0.0125 mg/lb) or less PO every 24 to 48 hours (Robertson 2008)

(c)    0.01-0.03 mg/kg once daily PO (Gunew JFMS 2008)

(3)   The injectable Metacam product is currently labeled for a one time dose of 0.3 mg/kg (0.14 mg/lb) SC. Oral dosing following this injectable dose is not  recommended

(4)   For accurate dosing it is recommended that a Tb or insulin syringe without needle be used to draw up the exact drug volume

(5)   Exercise great caution when using NSAIDs long term in cats.

f)       Cost

i)        Moderate




a)      Classification

i)        A benzodiazepine hypnotic sedative agent

b)      General Information

i)        Overall properties very similar to diazepam

ii)       Usually combined with ketamine or an opioid

c)      Advantages/Recommended use

i)        Similar to diazepam but can be given IM without pain and with excellent absorption

d)      Cautionary Information

i)        Given alone, can cause dysphoria, agitation, and difficult restraint

e)      Dosage Information

i)        Dogs & Cats

(1)   Generally 0.2 to 0.4 mg/kg (0.10 to 0.20 mg/lb) IV or IM

(2)   Preanesthetic Use (Choose one)

(a)    With Butorphanol 0.2 to 0.4 mg/kg (0.10 to 0.2 mg/lb) IV, IM

(b)   With Hydromorphone 0.1 to 0.2 mg/kg (0.05 to 0.1 mg/lb) IV, IM

(c)    With Oxymorphone 0.05 to 0.1 mg/kg (0.025 to 0.05 mg/lb) IV, IM

(d)   With Ketamine 2 to 10 mg/kg (1 to 5 mg/lb) IV, IM

f)       Cost

i)        Moderate





a)      Classification

i)        A pure mu opioid agonist

b)      General Information

i)        Duration of effect is 4 to 6 hours

c)      Advantages/Recommended use

i)        General premed suitable for healthy animals

ii)       Most commonly used in combination with acepromazine, an alpha-2 agonist, or a benzodiazepine sedative/tranquilizer

iii)     May provide greater sedation than can be achieved with hydromorphone or oxymorphone

d)      Cautionary Information

i)        Higher dosages can cause bradycardia and respiratory depression

ii)       More likely to cause transient hypotensive than hydromorphone, fentanyl, or oxymorphone

iii)     Often causes vomiting and defecation when given IM or SC

iv)     IV use is associated with histamine release

(1)   This is generally considered to be a transient low level concern and is unlikely if administered slowly

v)      There is significant sedative synergism between morphine and acepromazine in the dog

(1)   Acepromazine doses must be reduced appropriately

vi)     Should be used with caution in the cat if no sedative/tranquilizer is used

e)      Dosage Information

i)        Dog 0.5 to 1.0 mg/kg (0.25 to 0.50 mg/lb) SC, IM, or slowly IV

(1)   Acepromazine dose would be low end 0.005 to 0.040 mg/kg (0.0025 to 0.020 mg/lb)

ii)       Cats 0.25 to 0.5 mg/kg (0.125 to 0.25 mg/lb) SC, IM, or slowly IV

(1)   Acepromazine dose must be higher end 0.06 to 0.1 mg/kg (0.03 to 0.05 mg/lb)

iii)     Other uses

(1)   Constant rate infusion see section on CRIs

(2)   Epidural see section on epidurals

f)       Cost

i)        Low






1)   NALBUPHINE   Click here for detailed Nalbuphine information

a)      Classification

i)        Opioid

(1)   A mixed agonist/antagonist with primary agonistic activity at the kappa receptor

(a)    Generally antagonistic at the mu receptor

ii)       Nalbuphine is NOT a scheduled drug

      (1) There is no paperwork associated with the order or tracking of this drug

b)      General Information

i)        Limited analgesic efficacy may be adequate for very mild pain

ii)       Free of any expected undesirable effect

iii)     More effective for visceral (soft tissue) than somatic (orthopedic) analgesic

c)      Advantages/Recommended use

i)        Most effective as a component in procedural sedation in combination with medetomidine

      (1) Click here for feline nalbuphine/medetomidine videos

      (2) Click here for canine nalbuphine/medetomidine videos

ii)       Useful as a reversal agent for unwanted mu agonist effects (dysphoria, respiratory depression, sedation, etc)

iii)   May help stabilize patient CV dynamics and survivability when used during the treatment shock

d)      Cautionary Information

i)        Little worth mentioning

ii)   Very low bioavailability when given orally

iii)     Short duration of effect

(1)   Dogs - 30 to 45 minutes

(2)   Cats 45 to 60 minutes

iii)     Very high doses can produce excitement and dysphoria

e)      Dosage Information

i)        Dog & Cats

(1)   0.2 to 4.0 mg/kg (0.1 to 2.0 mg/lb) IV, IM

f)       Cost

i)        Low per dose Nalbuphine costs much less than butorphanol





a)      Classification

i)        An opioid antagonist

b)      General Information

i)        A short acting, pure antagonist

c)      Advantages/Recommended use

i)        To reverse unwanted effects of opioid medications

(1)   Can use small doses to partially reverse opioid effects

ii)       Duration of effect is 1 to 3 hours

d)      Cautionary Information

i)        Generally of shorter duration than most opioid agonists

(1)   Reversal effect may wear off before agonist has been cleared from body

(2)   Redosing may be necessary after 1 to 3 hours if undesirable agonist influence returns

ii)       Buprenorphine effects may not be reversible due to the high binding affinity

iii)     Butorphanol may not reverse as completely as pure Mu opioid agonists

e)      Dosage Information

i)        Dog & Cats - 0.02 to 0.1 mg/kg (0.01 to 0.05 mg/lb) IM or IV

(1)   Give 1/4 of calculated dose every 3 - 4 minutes until desired effect is achieved

f)       Cost

i)        Moderately low







a)      Classification

i)        A pure Mu opioid agonist

b)      General Information

i)        Duration of effect is 4 to 6 hours

c)      Advantages/Recommended use

i)        General premed for anesthetic candidates in all categories

ii)       Hypotensive patients

(1)   Unlike morphine, should not cause transient hypotension

iii)     Higher risk patient when the risk of vomiting needs to be minimized

d)      Cautionary Information

i)        Bradycardia is common

ii)       Noise hypersensitivity may be a problem

iii)     There is moderate sedative synergism between oxymorphone and acepromazine in the dog

(1)   Acepromazine doses must kept at the lower end of the dose range

iv)     Should be used with caution in the cat if no sedative/tranquilizer is used

e)      Dosage Information

i)        Dog 0.05 to 0.1 mg/kg (0.025 - 0.050 mg/lb) IM, IV

ii)       Cats 0.025 to 0.05 mg/kg (0.01 - 0.025 mg/lb) IM, IV

(1)   Combine with acepromazine 0.01 to 0.05 mg/kg (0.005 to 0.025 mg/lb) or medetomidine 0.001 to 0.015 mg/kg (0.0005 to 0.0075 mg/lb)

f)       Cost

i)        High


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Last modified: Friday February 06, 2009.