Individual Drugs

Chapter 1 Individual Drugs



ACEPROMAZINE











PromAce Fort Dodge Laboratories
Aceproject Vetus Animal Health


Approved for



▪ Dogs, cats, horses not intended for food


Features



▪ Phenothiazine tranquilizer or sedative

▪ Alpha antagonist

▪ Antiemetic

▪ Antihistaminic

▪ Antidysrhythmic


Uses



▪ Sedation and tranquilization
□ Before general anesthesia

□ Before travel or transport

□ In patients with “thunderstorm anxiety”

▪ Addition to opiate analgesic to produce neuroleptanalgesia


Precautions



▪ No analgesia (not to be used for painful procedures unless administered with analgesic)

▪ Use with caution in hypotensive or hypovolemic patients

▪ Thought to decrease seizure threshold; avoid excessive doses in seizure-prone patients

▪ Boxers, large-breed dogs, and geriatric patients may show increased sensitivity (avoid or use low dose)

▪ Splenic engorgement via red blood cell sequestration (hematocrit may drop up to 50%)

▪ Inhibits temperature regulation

▪ Risk of priapism in male horses. Priapism has been treated successfully in two horses with IV benztropine at 8 mg/horse. Use as soon as possible after priapism occurs.*


Doses




Doses of Acepromazine by Species

image


ATIPAMEZOLE








Antisedan Pfizer, Inc.


Approved for



▪ Dogs


Features



▪ Alpha2 adrenergic receptor antagonist

▪ Reverses all effects of alpha2 agents, including analgesia

▪ Increases heart rate and respiratory rate and reduces sedation

▪ Occasionally causes vomiting, diarrhea, and salivation


Uses



▪ Reversal of medetomidine sedation

▪ Can also be used to reverse other alpha2 agents (e.g., xylazine)

▪ Drug is formulated such that the volume of atipamezole required for intramuscular (IM) injection equals the volume of medetomidine administered intravenously (IV) or IM

▪ If ineffective after 10 to 15 minutes, use another IM dose at half the volume of medetomidine

▪ Approximately 45 minutes after medetomidine is given, use of atipamezole IV at half the volume of medetomidine is acceptable


Precautions



▪ Preferable to use IM route

▪ IV injection may cause excitement or aggression; inject slowly and in increments

▪ Because the analgesia of the alpha2 drug is reversed, use other agents for continued analgesia if necessary


Doses



Doses of Atipamezole by Species























Species IM (mg/kg) IV (mg/kg)
Horses* — 0.05–0.1
Dogs Use volume equal to volume of medetomidine used Use volume equal to half of volume of medetomidine used, preferably after approximately 45 minutes
Rabbits 0.25–0.5 0.001 IV, SC, IP†
Ferrets 0.1 1 IV, SC, IP‡

* Used in horses for detomidine overdose.


† Concentration of drug is 5 mg/ml. Dose rate of 0.001 mg/kg = 0.0002 mg/kg. A 5-kg rabbit would require 0.001 ml.


‡ Dose rate of 1 mg/kg = 0.2 ml/kg.



ATRACURIUM








Tracrium GlaxoSmithKline


Approved for



▪ No veterinary species


Features



▪ Nondepolarizing neuromuscular blocker

▪ Competes with acetylcholine (ACh) molecules released at the neuromuscular junction to bind with the ACh receptors on the postsynaptic membrane of the motor endplate without triggering a response

▪ Short duration of effect (25 to 35 minutes)

▪ Metabolized via ester hydrolysis and spontaneous Hofmann elimination (degradation at normal body temperature and pH)

▪ Requires refrigeration (drug deteriorates at room temperature)

▪ Safe in patients with hepatic or renal dysfunction


Uses



▪ Adjunct to general anesthesia; patient must be anesthetized before atracurium is administered

▪ Muscle relaxation for surgical procedures (e.g., ophthalmic, orthopedic)


Precautions



▪ No analgesia (not to be used for painful procedures unless administered with analgesic)

▪ Ventilation necessary

▪ May cause histamine release

▪ Reversal agent (anticholinesterase) required for reversal

▪ Prolonged effect in hypothermic and acidotic patients

▪ Aminoglycoside antibiotics (e.g., gentamicin) and volatile agents may increase duration of neuromuscular blockade

▪ Contraindicated in patients with myasthenia gravis or other neuromuscular disorders associated with weakness


Doses



Doses of Atracurium by Species











































Species IV—Initial Dose (mg/kg) IV—Repeat Dose (mg/kg)
Horses 0.2 0.1
Cattle 0.2 0.1
Sheep 0.2 0.1
Goats 0.2 0.1
Pigs 0.2 0.1
Dogs 0.25 0.1
Cats 0.22 0.1
Rabbits 0.2 0.1
Ferrets 0.2 0.1


ATROPINE











Atropine Butler Company
Atroject Vetus Animal Health


Approved for



▪ Dogs, cats, horses, cattle, sheep, swine


Features



▪ Naturally occurring alkaloid of Atropa belladonna

▪ Competitive antagonist of muscarinic cholinergic receptors


Uses



▪ Blocks the bradycardia associated with some drugs used in anesthesia

▪ Prevention of bradycardia resulting from excessive vagal stimulation or from anticholinesterase administration during neuromuscular blockade reversal

▪ Decreases bronchial and salivary secretions

▪ Bronchodilator

▪ Antidote for organophosphate toxicosis


Precautions



▪ Crosses the blood-brain barrier (pupillary dilation)

▪ Central nervous system (CNS) stimulation at high doses

▪ Sinus tachycardia may result; use with caution in patients with cardiac disease

▪ Contraindicated in patients with narrow-angle glaucoma and paralytic ileus

▪ Approximately one third of all domesticated rabbits have a naturally occurring atropinesterase enzyme that causes them to metabolize atropine more quickly than normal rabbits; may need to repeat dose frequently or use glycopyrrolate instead

▪ Can result in gastrointestinal stasis; avoid routine use in horse; use with caution in ruminants


Doses



Doses of Atropine by Species











































Species IV (mg/kg) IM, SC (mg/kg)
Horses 0.01–0.02 0.005–0.01
Cattle 0.02–0.04 0.005–0.01
Sheep 0.02–0.04 0.005–0.01
Goats 0.02–0.04 0.05–0.01
Pigs 0.06–0.08 0.04–0.06
Dogs 0.01–0.02 0.02–0.04
Cats 0.01–0.02 0.02–0.04
Rabbits 0.04–1 0.04–2
Ferrets 0.01–0.02 0.02–0.04


BUPIVACAINE








Marcaine Abbott Laboratories


Approved for



▪ No veterinary species


Features



▪ Amide local anesthetic

▪ Produces reversible depression of nerve conduction by blocking sodium channels

▪ Prevents rapid influx of sodium ions into nerve axon and production of action potential, resulting in local muscle paralysis and analgesia

▪ Slow onset (3 to 6 minutes)

▪ Long duration of action (4 to 6 hours)

▪ Metabolized by liver and excreted by the kidneys


Uses



▪ Regional analgesia and muscle relaxation

▪ Nerve blockade

▪ Analgesia for standing surgery (e.g., castration, dehorning, enucleation)


Precautions



▪ Never use IV because of cardiotoxicity

▪ Toxic dose for most species is 2 to 3 mg/kg

▪ Cats are most sensitive to toxic effects of local anesthetics

▪ Toxic effects of overdose produce either CNS effects (seizures) or cardiovascular effects (arrhythmias or cardiovascular collapse)

▪ Treatment after overdose is supportive


Doses


For single nerve block, use 0.5 to 2 ml per nerve site.




Doses of Bupivacaine by Species

image


BUPRENORPHINE








Buprenorphine Abbott Laboratories


Approved for



▪ No veterinary species


Features



▪ U.S. Drug Enforcement Administration (DEA) Schedule III controlled substance

▪ Partial agonist at mu opiate receptor

▪ Long onset (30 to 45 minutes)

▪ Long duration (4 to 6 hours)

▪ Minimal respiratory depression compared with pure opiate agonists

▪ Minimal cardiovascular depression compared with pure opiate agonists

▪ Injectable form can be used sublingually in cats without salivation or resentment, with pharmacokinetics similar to those seen with IV or IM administration; dose is 0.01 mg/kg*


Uses



▪ Premedication before surgery

▪ Mild-to-moderate pain relief

▪ Addition to sedative or tranquilizer to produce neuroleptanalgesia


Precautions



▪ Difficult to reverse because of high affinity of drug for mu opiate receptor


Doses



Doses of Buprenorphine by Species











































Species IV (mg/kg) IM, SC (mg/kg)
Horses NA NA
Cattle 0.005–0.01 0.005–0.01
Sheep 0.005–0.01 0.005–0.01
Goats 0.005–0.01 0.005–0.01
Pigs 0.01–0.1 0.01–0.1
Dogs 0.01–0.02 0.01–0.02
Cats 0.01–0.02 0.01–0.02
Rabbits 0.05–0.1 0.05–0.1
Ferrets 0.01–0.02 0.01–0.02

NA, Not appropriate.



BUTORPHANOL











Torbugesic Fort Dodge Laboratories
Torbutrol Abbott Laboratories


Approved for



▪ Dogs (Torbutrol)

▪ Cats (Torbugesic SA)

▪ Horses not intended for food (Torbugesic, Dolorex)


Features



▪ DEA Schedule IV controlled substance

▪ Agonist-antagonist with agonist activity primarily at kappa and sigma opiate receptors

▪ Antagonizes pure agonists such as morphine, oxymorphone, and fentanyl

▪ Significant antitussive activity in dogs

▪ No histamine release in dogs when given IV

▪ Fairly rapid onset (3 minutes IV; 20 minutes IM)

▪ Short-to-moderate duration (2 to 3 hours in dogs, 4 hours in horses)

▪ Minimal respiratory depression compared with pure opiate agonists

▪ Minimal cardiovascular depression compared with pure opiate agonists


Uses



▪ Premedication before surgery

▪ Mild-to-moderate pain relief

▪ Addition to sedative or tranquilizer to produce light level of neuroleptanalgesia

▪ Partial reversal of effects of pure agonists (e.g., in animals with slow recovery from anesthesia)

▪ Effective and well tolerated when administered orally in liquid form to cats


Precautions



▪ Caution must be exercised in patients with head trauma or conditions associated with increased cerebrospinal fluid (CSF) pressure

▪ Respiratory and cardiovascular functions and body temperature must be monitored

▪ Some excitement may occur in horses (head tossing, auditory sensitivity)

▪ Decrease in gut motility is possible, especially at high doses

▪ Do not use for very painful conditions; if additional analgesia is required, other opioids will not be effective for several hours after butorphanol has been administered because of its antagonistic activity


Doses



Doses of Butorphanol by Species











































Species IV (mg/kg) IM, SC (mg/kg)
Horses* 0.02–0.04 0.02–0.04
Cattle 0.01–0.04 0.01–0.04
Sheep 0.05† 0.05–0.5
Goats NRP 0.05–0.5
Pigs 0.1–0.5 0.1–0.5
Dogs 0.1–0.4 0.1–0.4
Cats 0.1–0.8 0.1–0.8
Rabbits 0.1–0.5 0.1–0.5
Ferrets 0.1–0.5 0.1–0.5

NRP, Not reported.


* Usually used with xylazine or acepromazine for premedication.


† Excitement may occur at twice this dose or above.



DETOMIDINE








Dormosedan Pfizer, Inc.


Approved for



▪ Mature horses and yearlings


Features



▪ Alpha2 agonist

▪ Sedative and analgesic

▪ Similar to xylazine but with longer duration

▪ Decreases MAC and the requirement for other anesthetic agents (MAC is the minimum alveolar concentration of an anesthetic agent that prevents response to a noxious stimulus in 50% of patients; MAC is used for comparison of agents)

▪ Initial and transient vasoconstriction and hypertension (peripheral effect), then vasodilation and hypotension (central effect)

▪ Decreased heart rate and cardiac output

▪ Second-degree atrioventricular (AV) block commonly seen

▪ Increased blood glucose probably occurs, as with xylazine

▪ Piloerection, sweating, salivation, tremors, or ataxia may occur

▪ Reversed with yohimbine or atipamezole


Uses



▪ Sedation and analgesia for standing procedures

▪ Sedation before general anesthesia


Precautions



▪ Do not use in horses with preexisting sinoatrial (SA) or AV block

▪ Do not use in horses with chronic renal failure

▪ Do not use in horses with respiratory disease

▪ Use cautiously for treatment of colic pain, because long duration may mask progression of disease

▪ Use cautiously in horses with endotoxic shock

▪ Use cautiously in stressed horses

▪ Horses may respond suddenly to external stimuli even though apparently sedated


Doses



Doses of Detomidine by Species















Species IV (mg/kg) IM (mg/kg)
Horses 0.02–0.04 0.02–0.04
Cattle* 0.03–0.06 0.03–0.06

* Not approved for use in this species.



DIAZEPAM










Diazepam Baxter Healthcare Corporation
Abbott Laboratories


Approved for



▪ No veterinary species


Features



▪ DEA Schedule IV controlled substance

▪ Benzodiazepine

▪ Acts at gamma-aminobutyric acid (GABA) receptor

▪ Anxiolytic

▪ Muscle relaxant

▪ Hypnotic

▪ Anticonvulsant


Uses



▪ Sedation and tranquilization

▪ Premedication—add to opiate analgesic to produce neuroleptanalgesia

▪ Treatment of muscle fasciculation induced by propofol or other anesthetics

▪ Treatment of seizures


Precautions



▪ No analgesia (not to be used for painful procedures unless administered with analgesic)

▪ Not well absorbed after IM administration (midazolam recommended)

▪ May cause excitement when administered alone (especially in cats and horses)

▪ Administer slowly IV to prevent hypotension (propylene glycol vehicle)

▪ Care required in patients with hepatic or renal disease or respiratory depression

▪ Care required in debilitated patients or those in shock


Doses



Doses of Diazepam by Species











































Species IV (mg/kg) IM, SC (mg/kg)
Horses* 0.01–0.03 NA
Cattle 0.2–0.4 0.55–1
Sheep 0.2–0.4 0.2–1
Goats 0.2–0.4 0.2–1
Pigs 0.4–0.8 0.5–1.5
Dogs 0.1–0.2 0.1–0.5
Cats† 0.1–0.2 0.1–0.4
Rabbits 0.4–0.8 0.5–2
Ferrets 0.4–0.8 0.5–2

NA, Not appropriate.


* Not to be used alone; best used after premedication and as part of induction technique (e.g., with ketamine).


† Excitement may occur when used alone, especially IV; best used with other agents.



DOBUTAMINE










Dobutamine Abbott Laboratories
Baxter Healthcare Corporation


Approved for



▪ No veterinary species


Features



▪ Primarily a beta1agonist

Related posts:

  1. Blood and Blood Substitutes
  2. Case Management
  3. Fluids
  4. Drug Combinations

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Oct 14, 2016 | Posted by in SUGERY, ORTHOPEDICS & ANESTHESIA | Comments Off on Individual Drugs

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