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A
1) ACEPROMAZINE
a)
Classification
i)
phenothiazine tranquilizer
b)
General Information
i)
Very inexpensive, effective tranquilizer for healthy animals
ii)
Clinically more effective in dogs than cats
iii)
Duration of effect is 6 to 8 hours
(1)
Some pets appear sedate for more than 12 hours
iv)
Acepromazine can be used alone, as a premedicant. However, it is
more effective to use Acepromazine in combination with an opioid narcotic
agent
(1)
The addition of an opioid reduces the acepromazine dose, and
therefore also reduce the likelihood of hypotension or sustained,
excessive sedation that can occur
c)
Advantages/Recommended use
i)
Decreases patient stress and anxiety
ii)
Helps protect against catecholamine induced arrhythmias
iii)
Decreases amount of induction and maintenance anesthetics
iv)
The injectable product can be given orally @
1.0 to 2.0 mg/kg (0.5 to 1.0 mg/lb) for tough animals
(1)
For extremely difficult patients, acepromazine at above dose can be
combined with 5 to 20 mg/kg (2.5 to 10 mg/lb) telazol solution and given orally
on an empty to produce effective chemical restraint
(a)
At the upper dose range expect laterally recumbent animals within
30 to 45 minutes
d)
Cautionary Information
i)
Use of acepromazine as a sole agent is not recommended
ii)
Can have profound and prolonged effects when used on older or
debilitated patients
iii)
There are still references to acepromazine lowering the seizure
threshold for epileptic patients (increased seizure risk)
(1)
Many anesthetists feel this is not a significant risk at the doses
currently recommended
iv)
May decrease seizure potential
in myelogram cases (decreased seizure risk)
v)
May decrease PCV (up to 30%)
(1)
Avoid in anemic patients
vi)
Avoid in splenic disease patients
(1)
Induces splenic enlargement/engorgement
vii)
Not well tolerated by patients with liver disease
viii)
Many feel that Boxers require lower doses than other dogs of
similar size and disposition
e)
Dosage Information
i)
Dogs
(1)
Dose ranges from 0.005 mg/kg to 0.1 mg/kg (0.0025 mg/lb to 0.05
mg/lb) IV, IM, SC
(a)
Combine with an opioid
(b)
Most commonly used at 0.010 to 0.040 mg/kg (0.005 to 0.02 mg/lb)
when combined with an opioid
(2)
Dosing is more appropriately considered based upon body surface
area
(a)
The heavier the patient, the lower the dose per unit of body weight
(3)
Maximum total dose is 2 mg regardless of weight
(a)
Some go as high as 3 mg total dose
ii)
Cats
(1)
Dose ranges from 0.020 to 0.10 mg/kg (0.01 mg/lb to 0.05 mg/lb) IV,
IM, SC
(a)
Combine with an opioid
(2)
Smaller, younger patients usually require 0.06 to 0.10 mg/kg (0.03
to 0.05 mg/lb)
(3)
When combined with a mu agonist opioid give 0.06 to 0.10 mg/kg
(0.03 to 0.05 mg/lb)
(a)
Inadequate acepromazine dose associated with undesirable excitement
f)
Cost
i)
Very low
2)
AMANTADINE
a)
Classification
i)
Developed initially
as a human antiviral drug,
also used to treat Parkinson’s disease
b)
General Information
i)
An oral prescription medication capable of NMDA antagonism useful
in managing the central sensitization component of chronic pain management
ii)
The dopamine selectivity of amantadine’s
monoamine reuptake inhibition appears to allow for coadministration with
other less selective monoamine reuptake inhibitors (tramadol, TCAs, SSRIs,
MAO inhibitors).
c)
Advantages/Recommended use
i)
Chronic pain management
d)
Cautionary Information
i)
Amantadine is excreted, primarily unchanged, in the urine
(1)
Consider reduced doses, if used at all, for patients with impaired
renal function
ii)
May potentiate the effects of sedative medications
iii) Use with caution in nursing animals
iv) Side effects are rare, but can include agitation or
diarrhea
e)
Dosage Information
i)
Dogs & Cats
(1)
3 to 5 mg/kg (1.25 to 2.5 mg/lb) SID PO
(2)
Can be given continually or as a 7 to 14 day pulse therapy
ii)
Available in 100 mg gelcaps and 10 mg/ml liquid
f)
Cost
i)
Low
3)
AMITRIPTYLINE (TCAs)
a)
Classification
i)
Tricyclic antidepressant prescription drug
b)
General Information
i)
Monoaminergic reuptake inhibition (serotonin, norepinephrine)
enhances central pain inhibition
ii)
Possible opioid receptor activity as well or, at least, enhanced
effectiveness of concurrently administered opioids
c)
Advantages/Recommended use
i)
Chronic pain management
d)
Cautionary Information
i)
Do not combine with other TCAs, SSRIs, MAO inihibitors, or
tramadol
due to the risk of serotonin syndrome.
ii)
May potentiate the effects of sedative medications
iii)
Has anticholinergic effects
e)
Dosage Information
i)
Dogs
(1)
1 to 2 mg/kg (0.5 to 1.0 mg/lb) SID to BID PO
ii)
Cats
(1)
2.5 to 12.5 mg/cat SID
iii)
Available in 10, 25, 50,
75, 100, and 150 mg tablets
f)
Cost
i)
Moderate
(1)
May need to be compounded to allow for proper dosing
4)
AMIDATE
a)
Abbott’s brand name for Etomidate
5)
ATIPAMAZOLE
a)
Classification
i)
Alpha-2 antagonist
b)
General Information
i)
Reversal agent for medetomidine or xylazine
c)
Advantages/Recommended use
i)
Completely, permanently reverses medetomidine effects
(1)
Can be used at partial dose for partial effect
d)
Cautionary Information
i)
Reversing all of medetomidine’s sedative effects will also lead
to loss of analgesic effect
e)
Dosage Information
i)
Dogs
(1)
Normally match route and volume of medetomidine given
(a)
Reduce dose according if sedative effects of medetomidine have warn
off
(b)
Reduce dose accordingly if you prefer to retain some analgesic and
sedative effect
ii)
Cats
(1)
Normally give 1/2 the volume of the medetomidine given as a
starting point
(a)
Reduce dose according if sedative effects of medetomidine have warn
off
(b)
Reduce dose accordingly if you prefer to retain some analgesic and
sedative effect
f)
Cost
i)
High
6)
ATROPINE
a)
Classification
i)
Anticholinergic
b)
General Information
i)
Decreases salivary secretions
(1)
Can make them thicker, more ropey
(a)
Only reduces serous portion of salivary secretions leaving the
thicker mucoid portion
ii)
Increases heart rate
c)
Advantages/Recommended use
i)
Prior to procedure that stimulate strong vagal effect
(1)
Bronchoscopy
(a)
May need to postpone until after respiratory diagnostics have been
completed
ii)
Prior to dental procedures to decrease salivary secretions
(1)
Most would argue against routine use here
iii)
Prior to brachycephalic anesthesia
(1)
Brachycephalics tend to have higher vagal tone making routine
anticholinergic use a consideration
(2)
To decrease salivary secretions
(a)
Most would argue against routine use here
iv)
C-sections
(1)
Atropine does cross placenta making it preferred for use in this
situation should the bitch become clinically bradycardic
v)
Cardiac emergencies involving bradycardia or cardiac arrest
(1)
A more rapid, forceful effect
(2)
Glycopyrrolate is a definite second choice in emergency cases
(a)
Slower onset
(3)
Hypothermia results in decreased depolarization of cardiac
pacemaker cells, causing bradycardia. Since this bradycardia is not
vagally mediated, it can be refractory to atropine.
d)
Cautionary Information
i)
Partial dosing can lead to a centrally mediated bradycardic effect
ii)
Use with caution in tachycardic patients
(1)
Tachyarrhythmias can be an undesirable effect
(2)
Increased heart rate increases myocardial oxygen demand
iii)
Pupilary dilation may be undesirable for certain ophthalmic
procedure
iv)
Duration of effect is much shorter than glycopyrrolate
(1)
Only about 45 minutes
v)
Be especially cautious when used with patients on
amitriptyline as that behavioral medication possesses anticholinergic
properties
e)
Dosage Information
i)
Dogs & Cats
(1)
0.02 to 0.04 mg/kg (0.01 to 0.02 mg/lb) IV, IM, SC
(a)
This works out to 1 cc per 10 to 20 kg (20 to 40 lb)
f)
Cost
i)
Very low
B
1)
BENZODIAZEPINE
a)
This is the name of the family of drugs that includes diazepam,
midazolam, and zolazepam
2)
BUPIVACAINE
a)
Classification
i)
Local anesthetic
b)
General Information
i)
Slower onset of action (20 - 30 minutes) but longer duration of
effect (3 -5 hours) when compared to lidocaine
(1)
Combine with either 0.075 mg/kg (0.035 mg/lb) morphine or 0.003
mg/kg (0.0015 mg/lb) buprenorphine to extend the analgesic duration of
local blocks to approximately 20 hours 1,2
(2)
Epidural effect is longer
ii)
With local anesthetics, volume is more important than concentration
(1)
Dilute with sterile water when blocking larger areas
(a)
Commonly diluted to 50% to 33% bupivacaine (1:1 to 2:1 ratio of
sterile water to bupivacaine)
c)
Advantages/Recommended use
i)
Local nerve blocks
ii)
Epidural anesthesia
(1)
May cause a lengthy motor block
iii)
Intra-articular after joint closure
d)
Cautionary Information
i)
More potential for toxicity than lidocaine
(1)
Calculate doses very carefully
(2)
Never administer IV
(3)
Toxic signs can be CNS or cardiac
(a)
Cardiac toxicities are potentially fatal
(4)
There is some debate about the use of intrapleural bupivacaine if a pericardiectomy has been
performed due to the increased potential for cardiac toxicity
e)
Dosage Information
i)
Local blocks
(1)
Dog - generally 1.0 mg/kg up to a maximum dose of 2 mg/kg (1 mg/lb)
(2)
Cats – maximum of 1.0 mg/kg (0.5 mg/lb)
ii)
Intra-articular
(1)
Generally whatever will fit after joint closure
(a)
Dogs - up to the maximum of 2 mg/kg (1 mg/lb)
(b)
Cats – up to the maximum of 1 mg/kg (0.5 mg/lb)
iii)
Epidural
(1)
Dogs and Cats – 1 mg/kg (0.5 mg/lb)
iv)
Other uses
(1)
Intercostal blocks
(2)
Brachial plexus blocks
(3)
Ring blocks
(4)
Dental Blocks
f)
Cost
i)
Moderate
3)
BUPRENORPHINE
a)
Classification
i)
Opioid
(1)
Partial mu agonist of extremely high affinity
(2)
Some kappa antagonism
(3)
Class III
b)
General Information
i)
Good all around analgesic for mild to moderate pain free of any
expected undesirable effect
(1)
Anecdotal reports of dogs receiving 0.2 mg/lb IV on a QID basis for
several doses without negative consequences (M. Richey, DACVA)
ii)
Minimal, if any, sedative effect
iii)
Buprenorphine has a delayed onset
(1)
30 minutes to peak effect when given IV
(2)
45 to 60 minutes to peak effect when given IM
iv)
Duration of effect is influenced by dose
(1)
3 to 4 hours at 0.010 mg/kg (0.005 mg/lb) dose
(2)
6 to 8 hours at 0.020 mg/kg (0.010 mg/lb) dose
(3)
8 to 10 hours at 0.030 mg/kg (0.015 mg/lb) dose
(4)
10 to 12 hours at 0.040 mg/kg (0.020 mg/lb) dose
c)
Advantages/Recommended use
i)
General soft tissue surgery
ii)
Light orthopedic surgery
iii)
In cats, studies have shown that
bioavailability is the same whether given IV, IM, or via buccal oral
mucosa (bioavailability is poor from GI tract – give sublingually or in
lateral cheek pouch)
(1)
This transmucosal absorption is influenced by the alkaline pH of
feline saliva
(a)
There is, as yet, no support for effective oral absorption by the
dog
(2)
Excellent option for home analgesic management in cats
d)
Cautionary Information
(1)
Difficult to reverse if undesirable effects arise
(2)
Would be expected to antagonize other pure mu agonists like
morphine, hydromorphone, fentanyl, and oxymorphone
e)
Dosage Information
(1)
Dogs – 0.010 to 0.040 mg/kg (0.005 – 0.02 mg/lb) IM or IV
(2)
Cats - 0.010 to 0.040 mg/kg (0.005 – 0.02 mg/lb) IM, IV, or Tramsmucosally
f)
Cost
i)
Moderate at low end of dose range - high at upper dose range
4)
BUTORPHANOL
a)
Classification
i)
Opioid
(1)
A mixed agonist/antagonist with primary agonistic activity at the
kappa receptor
(a)
Generally antagonistic at the mu receptor
b)
General Information
i)
Good all around analgesic for mild pain free of any expected
undesirable effect
ii)
Little, or no respiratory depression at clinical doses
iii)
Duration of effect is 30 minutes to 1 hour in dogs and 1 to 3 hours
in cats
c)
Advantages/Recommended use
i)
General soft tissue surgery
ii)
More effective for visceral (soft tissue) than somatic (orthopedic)
analgesic
d)
Cautionary Information
i)
Short duration of effect
(1)
Dogs - 30 minutes to 1 hour
(2)
Cats - 1 to 3 hours
ii)
Higher doses can produce excitement and dysphoria
e)
Dosage Information
i)
Dog & Cats
(1)
0.2 to 0.4 mg/kg (0.1 to 0.2 mg/lb) IV, IM, SC
(a)
0.2 mg/kg (0.1 mg/lb) is the most commonly selected dose
f)
Cost
i)
Moderate (to high if given every few hours)
C
1)
CARPROFEN
a)
Classification
i)
A COX2 selective NSAID
b)
General Information
i)
Effective anti-inflammatory/analgesic generally free of significant
GI side effects
c)
Advantages/Recommended use
i)
Short term use for acute pain
ii)
Long term use in chronic pain for tolerant patients
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 – 2.20 mg/kg (1.0 mg/lb) SC, PO BID or 4.4 mg/kg (2.0 mg/lb)
SC, PO SID
ii)
Cats – 1 to 4.0 mg/kg (0.45 to 1.8 mg/lb) SC one time only
f)
Cost
i)
Moderate |
