Veterinary Anesthesia & Analgesia Support Group
Practical Information for the Compassionate Veterinary Practitioner
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    T Drugs
    Alphabetical Drug Summaries
    Dr. Bob Stein


a)      Classification

i)        50/50 mixture of a benzodiazepine (Zolazepam) & a dissociative agent (Tiletamine)

b)      General Information

i)        Similar to Ketamine and Diazepam

ii)       Can be used for induction in dogs and cats or as the exclusive agent for short procedures in cats

iii)     Tiletamine is capable of providing the loading dose for NMDA dorsal horn windup antagonism prior to ketamine CRI use

c)      Advantages/Recommended use

i)        Healthy animals in the Good to Excellent category

(1)   More ideal for cats vs. dogs

(2)   An acceptable induction agent for sighthounds

d)      Cautionary Information

i)        Avoid if:

(1)   Intracranial disease is suspected (can raise ICP)

(2)   Renal insufficiency is present (renal clearance)

ii)       Somewhat more stormy recoveries in dogs compared to Ketamine/Diazepam

(1)   The ½ life of zolazepam is much longer than the ½ life of the tiletamine in cats

(2)   The ½ life of zolazepam is shorter than the ½ life of the tiletamine in dogs increasing the risk that the patients will be more agitated during the recovery

(a)    This is less of an issue if a longer procedure over 1.5 hours

e)      Dosage

i)        Routine induction

(1)   Dog & Cat – 2 mg/kg (1 mg/lb) IV bolus

(a)    Sedated or pre-existing CNS depression or debilitation - draw up 2 mg/kg (1 mg/lb), give 25 - 50% as bolus then additional increments to effect

ii)       Vicious, aggressive dogs

(1)   5 mg/kg (2.5 mg/lb) IM - usually reach lateral recumbancy within 10 minutes

(2)   May be combined with acepromazine for more dramatic effect

iii)     Routes of administration

(1)   IV – allows for lower telazol doses

(2)   IM more rapid in effect but more painful

(3)   SC - somewhat less painful and somewhat lower effect but SQ administration is still a rapidly acting route

f)       Cost

i)        Moderately low










a)      Classification

i)        Ultra-short acting thiobarbiturate

b)      General Information

i)        Various concentration (2.5% and 5% solutions are the most common)

c)      Advantages/Recommended use

i)        Healthy animals in the Good to Excellent category

d)      Cautionary Information

i)        It is safer to consistently use the same concentration solution within a given facility rather than stocking both 2.5% and 5% solutions

ii)       Not recommended for use with sight hounds

(1)   Lower volume of distribution and altered metabolism make for a very narrow therapeutic index

iii)     Can cause significant decrease in PCV

(1)   Thiopental (and Acepromazine) cause splenic pooling of RBCs leading to a rapid decrease in PCV of up to 30%

iv)     Can induce myocardial irritability

(1)   Usually bigeminal

(2)   Treatment not required if stable cardiac output

v)      There is an accumulative effect with this agent

vi)     Extravascular thiopental may produce tissue necrosis

(1)   Infiltrate area with saline, 0.5 to 1 mg of dexamethasone and 1 mg/kg (0.5 mg/lb) of lidocaine

(2)   Additionally, a gauze soaked in DMSO can be wrapped over the site

vii)   Unused thiopental should be discarded whenever any precipitate is noted in solution or when 4 weeks has transpired since mixing even if no precipitate is noted

e)      Dosage Information

i)        Dog & Cat

(1)   Begin with 12 mg/kg (6 mg/lb)

(a)    Administer 4 to 6 mg/kg (2 - 3 mg/lb) rapid bolus initially followed by additional small boluses to effect

(i)      Excessively slow injection may precipitate unwanted excitement

(b)   Reduce initial bolus in proportion to degree of sedation produced by premeds

(2)   Maximum dose is 16 mg/kg (8 mg/lb)

(3)   If at any point the canine patient is nearly, but not quite, able to be intubated, the addition of 2 mg/kg (1 mg/lb) lidocaine IV, may deepen the anesthetic effect and facilitate successful intubation

(a)    This strategy is useful when minimizing the induction agent for more critical patients

(b)   Cats are more sensitive to the toxic effects of lidocaine (CNS stimulation, seizures). Lidocaine is not recommended for use in cats at this time.

f)       Cost

i)        Moderate




a)      Classification

i)        A dissociative agent

b)      General Information

i)        Combined with zolazepam to produce Telazol

ii)       For more information see Telazol





a)      Classification

i)        An analgesic medication with a dual mode of action

(1)   Mu opioid receptor agonist

(2)   Monoamine reuptake inhibitor

b)      General Information

i)         An uncontrolled, oral analgesic for use in dogs and cats

c)      Advantages/Recommended use

i)       Acute or chronic mild to moderate pain management

ii)       May be combined with other classes of analgesics including pure mu agonist opioids, NSAIDs, NMDA antagonists, and calcium channel blockers

d)      Cautionary Information

i)        May decrease seizure threshold although the risk appears quite low

ii)   Do not combine with SSRIs or MAO inhibitors due to the risk of serotonin syndrome

(1)   Use caution when combining tramadol with TCAs to minimize the risk of serotonin syndrome

iii)   Metabolism is principally via hepatic biotransformation, with a small amount excreted unchanged by the kidneys. Reduce dose or discontinue if significant hepatic or renal dysfunction exists

iv)  Side effects, though rare, may include GI upset and sedation

v)   This is a bitter medication that is not well accepted by cats even when compounded in a cat friendly liquid base. 

e)      Dosage Information

i)        Dog

(1)    3 to 5 mg/kg (0.5 to 2.5 mg/lb) TID to QID (up to 6 times daily at lower dose)1

(b)   Anecdotal reports include 10 mg/kg QID for more severe pain

iii)      Cats

(1)    1 to 2 mg/kg (0.5 to 1.0 mg/lb) BID to QID

ii)       Tramadol is available in 50 mg tablets

f)       Cost

i)        Moderately low


        1 Pharmacokinetics of tramadol and the metabolite O-desmethyltramadol in dogs. KuKanich B, Papich MG. J Vet Pharmacol Ther. 2004 Aug;27(4):239-46
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Last modified: August 13, 2012 .