Unit 2- Sedatives Flashcards
Sedatives MOA
Depress the CNS at the basal ganglia, hypothalamus, limbic system, and brain stem through dopamine, adrenergic, serotonin, opioid, and GABA receptors
Sedative Pharmacologic Effects
Bradycardia, hypotension, tachycardia, hypoventilation, and decreased GI motility
Phenothiazine Derivative MOA
Block dopamine action and reduce action of serotonin
Benzodiazepine MOA
Enhance inhibitory effect of GABA
α2-adrenergic Agonist MOA
Stimulate α2-adrenoreceptors to inhibit norepinephrine release by negative feedback mechanism
Butyrophenone Derivative MOA
Block dopamine receptors
Opioid MOA
Stimulate opioid receptors
Phenothiazine Derivatives
Chlorpromazine, Acepromazine, Promazine, Triflupromazine
Phenothiazine Pharmacologic Effects
Depression of brain stem and connections to cerebral cortex, decrease spontaneous motor activity, no analgesia
Chlorpromazine Pharmacologic Effects
Sedation, antagonist of apomorphine emesis in dogs, block FSH and LH release, increase prolactin, reduce myocardium contractility, arrhythmia
Chlorpromazine Adverse Effects
Extrapyramidal signs, hyperesthesia and excitement of horses and penile prolapse
Extrapyramidal Signs
Movement Disorders
Chlorpromazine Contraindications
Hypovolemia or shock, hepatic disfunction, combine with atropine in dogs, severe side effects in horses
Acepromazine
More potent shorter acting than chlorpromazine, highly protein bound in horses, immobilizes large animals
Promazine
Less potent than chlorpromazine, duration dose dependent
Triflupromazine
Sedative and anti-emetic, higher risk of side effects
GABA A Receptor
Ligand-gated ion channel causing hyperpolarization
Bezodiazepines
Diazepam, Midazolam, Clonazepam, Zolazepam, Alprazolam
Benzodiazepine Pharmacologic Effects
Minimal cardiovascular effects, depressed respiratory, muscular relaxation
Benzodiazepine Uses
Sedative, anti anxiety, anticonvulsant, muscle relaxant with ketamine, not reliable in horses, dogs, or cats
Diazepam
Sedative, anxiolytic, behavior modification, muscle relaxant, and anticonvulsant in dogs and horses, increases appetite in cats
Diazepam Adverse Effects
Impaired coordination, lethargy, aggression and excitement, and hepatotoxicity for cats
Xanax
Not for use in dogs
Clonazepam
Stronger than diazepam with shorter half life
Midazolam
Neuroleptanalgesic with opioids in dogs
Zolazepam
Used with Tiletamine for anesthesia
Catecholamines
Dopamine, Norepinephrine, Epinephrine released in response to stress and acting on GPCR adrenergic receptors
α2-Adrenergic Agonists
Xylazine, Medetomidine, Dex-medetomidine, Detomidine, Clonidine
α2-Adrenergic Agonist Pharmacologic Effects
Sedation, analgesia, skeletal muscle relaxation, emesis in cats, reduced GI motility and secretion, hypertension followed by hypotension and bradycardia
α2-Adrenergic Agonist Uses
Sedative, analgesic, immobilizer, pre-anesthetic, avoid combining with ketamine in weak animals
Xylazine Hydrochloride
Wide margin of safety, poor efficacy in swine, short term anesthetic with ketamine, causes emesis in cats and dogs
Dexmedetomidine
Most potent and selective α2-Agonist, no respiratory depression, shortens time to extubation
Xylazine in Horses
Not for dosage in carotid artery, inhibits insulin leading to hyperglycemia, cardiac aberration, renal insufficiency, hepatic damage, and epilepsy, should only be combined with ketamine in young healthy animals, not for late pregnancy
Butyrophenone Derivatives
Azaperone and Droperidol
Azaperone
Sedative and anti-emetic effects in pigs and swine, pre anesthetic, D2 agonist
Droperidol
More potent than promazine and chlorpromazine in dogs, restrains aggressive dogs, combined with fentanyl, contraindicated for use with epinephrine
Opioids
Morphine, Oxymorphone, Fentanyl, Cerfentanil
Analeptics
Stimulate the brain, speeding up mental and physical processes
Amphetamine MOA
Enhance release of dopamine and norepinephrine into the synapse by blockign reuptake
Amphetamine Pharmacologic Effects
Used in emergency situations, increases heart rate, blood pressure, metabolism, and temperature
Amphetamine Adverse Effects
Seizure, hypertension, arrhythmia, hyperventilation, and hepatotoxicity
Doxapram
Stimulates respiration by stimulating medullary respiratory centers and activating carotid and aortic chemoreceptors to arouse from anesthetic overdose
Doxapram Adverse Effects
Seizure, hyperventilation, respiratory alkalosis, hypertension, and arrhythmia
Signs of Amphetamine Toxicity in Dogs
Agitation, tachycardia, panting, tremors, increased temperature, vomiting, drooling, seizures
Cocaine
Blocks reuptake of dopamine from the synapse
