Lect 8

• Tranquilizers, Neuroleptics, and Sedatives are drugs that act on the Central Nervous System (CNS) and have a mechanism of action that affects the CNS at the basal ganglia, hypothalamus, limbic system, and brain stem.
• Azaperone is used as a pre - anesthetic agent prior to general anesthesia or caesarean section, and is occasionally used as a behavior modifying agent.
• The recommended dose of Amphetamines for dogs and cats is 1 - 5 mg/kg, IV, and for horses it is 0.5 - 1 mg/kg, IV.
• Droperidol should not be used with epinephrine, and is used in combination with fentanyl (opioid) for induction of neuroleptanalgesia.
• Droperidol is a potent D2 antagonist with some histamine and serotonin antagonist activity, and is more potent than chlorpromazine and promazine in dogs.
• Amphetamines enhance the release of DA and NE onto the synaptic gap by blocking dopamine and/or NE reuptake.
• α 2 - Adrenergic Agonists, such as Clonidine, Block central dopamine D2 receptors.
• Azaperone is a butyrophenone neuroleptic with sedative and antiemetic effects, and is a potent D2 antagonist with some α 1 - adrenergic, muscarinic - cholinergic and histamine receptors.
• Droperidol is used as a chemical restraining agent in aggressive dogs.
• Opioids, such as Morphine (μ+; κ+), Oxymorphone (μ+; κ+), and Carfentanil (μ+; κ+; δ+), stimulate opioid receptors (mu ( µ ), kappa ( κ ), and delta ( δ )).
• Tranquilizers and Sedatives, such as Benzodiazepines, enhance GABA neurotransmission.
• Adverse effects of Amphetamines include high doses may induce seizures, hypertension, arrhythmias, and hyperventilation, and hepatotoxicity.
• CNS Stimulants, also known as Analeptics, promote neurotransmission.
• Benzodiazepines (BZDs) are GABA agonists with minimal cardiovascular effects, depressed respiratory effects, and muscular relaxation due to effects in the spinal cord.
• Chlorpromazine is used before surgery or veterinary examinations and procedures (X-ray) or grooming sessions with nervous/excitable animals.
• Diazepam (Valium R) is a benzodiazepine (BZD) derivative with high lipid solubility, wide distribution throughout the body, crosses BBB, liver metabolism, and is used in Vet Med to sedate, reduce anxiety, panic, promote behavioral changes, or induce muscle relaxation.
• Promazine has higher risk of side effects than other phenothiazine derivatives.
• Chlorpromazine is a pre-anesthetic medication that appears as a yellow, odorless, bitter tasting water soluble powder and is administered by IM or IV.
• Chlorpromazine is 10-20 times more potent than chlorpromazine, producing mild to moderate sedation of shorter duration.
• The duration of acepromazine sedation is dose-dependent and can vary within 4-6 hr.
• Acepromazine is used as a sedative and anti-emetic agent in animals.
• Acepromazine has a higher risk of side effects than other phenothiazine derivatives.
• Benzodiazepines (BZDs) are used as sedatives, anti-anxiety, anti-panic disorders, anticonvulsants in all domestic species, and muscle relaxant when given together with ketamine.
• Chlorpromazine is used as a tranquilizer-sedative for controlling intractable animals and to immobilize large animals.
• Triflupromazine is used as a tranquilizer in horses.
• Chlorpromazine is highly protein bound and has a fair volume of distribution in horses.
• Promazine is used occasionally in animals for sedation and as an antiemetic agent.
• Acepromazine, structurally related to chlorpromazine, is administered by IM and IV and is 10-13 times less potent than chlorpromazine, producing mild to moderate sedation.
• Benzodiazepines (BZDs) bind to GABA receptors and enhance the inhibitory effect of GABA.
• Benzodiazepine (BZD) derivatives are prescription only tranquilizers.
• Alprazolam (Xanax) is used as a pre-anesthetic, sedative, and to increase appetite in cats and control behavior disorders.
• Catecholamines include Dopamine, Norepinephrine (NE, also called noradrenaline), and Epinephrine (E, also called adrenaline).
• Catecholamines are released in response to emotional or physical stress, also known as the 'fight-or-flight' response.
• α2-adrenergic agonists are used as powerful sedation, powerful analgesia, skeletal muscle relaxation due to effects in the CNS, emesis (cats, less in dogs), reduced both GI motility and secretion (control of diarrhea), and hypertension followed by hypotension, bradycardia.
• Midazolam (used in combination with an opioid in older dogs as a neuroleptanalgesic) is used as a pre-anesthetic, sedative, and to increase appetite in cats and control behavior disorders.
• Adverse effects of Clonazepam include lethargy.
• High doses of Doxapram may induce seizures.
• Clonazepam can be administered orally, IV, or rectally.
• Xylazine, Medetomidine, Dexmedetomidine (Dexdomitor R), Detomidine, Clonidine are used as sedative, analgesic, and immobilizing agents, as a pre-anesthetic, and as a part of the anesthetic combination.
• Clonidine is used in horses.