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M
1)
MEDETOMIDINE
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
i)
DO NOT USE AS SOLE AGENT AT BOX LABEL DOSES
(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)
2)
MELOXICAM
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
3)
MIDAZOLAM
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
4)
MORPHINE SULFATE
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
N
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
2)
NALOXONE
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
O
1)
OXYMORPHONE
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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