Lect 15

• DRUGS Acting on the Central Nervous System (CNS) REVIEW Session Anait S. Levenson, M.D., Ph.D.
• The major pharmacological and psychological effects produced by CNS acting drugs include: analgesia, sedation, euphoria, and altered mental state.
• The major types of CNS acting drugs include: analgesics, tranquilizers, anticonvulsants, antiemetics, pre-anesthetics, and anesthetics.
• Neurons communicate through action potential, neurotransmitters, synapses, and receptors.
• Depolarization and hyperpolarization are key concepts in understanding neuronal communication.
• Major Classes of CNS Drugs include Anesthetics, Barbiturates, Non-barbiturates, and Dissociative drugs.
• Barbiturates include Thiopental, Thiamylal, Methohexital, Pentobarbital, and Phenobarbital.
• Anesthetics include Volatile agents such as Isoflurane, Sevoflurane, Desflurane, Halothane, and Dietyl ether, and Nonvolatile agents like Methoxyflurane.
• Dissociative drugs include Ketamine, Tiletamine, Telazol R.
• Non-barbiturates include Propofol, Etomidate, Alphaxalone.
• Major neurotransmitters include GABA, GABA-A, GABA-B, Dopamine, D2-like, Serotonin, 5-HT3, Substance P, NK1, Histamine, H1, and Acetylcholine, M1.
• G protein-coupled receptors (GPCRs) are important for drug actions.
• Sites and mechanisms of drug action can be described.
• Drugs and the blood-brain barrier (BBB) are key factors in understanding CNS drugs.
• Major classes of CNS drugs include Analgesics, Tranquilizers, Anticonvulsants, Antiemetics, Pre-Anesthetics, and Anesthetics.
• Opioids are a major class of analgesics and their receptors and relative analgesic effects should be reviewed.
• Tranquilizers are a major class of CNS drugs and their major classes and their mechanisms of action should be reviewed.
• Benzodiazepines (BDZs) include Diazepam (emergency, dogs), Lorazepam (geriatric dogs).
• Major classes of anticonvulsants include Barbiturates, Benzodiazepines (BDZs), Unconventional Drugs, and Hydantoins.
• GABA and GABA A receptor; adverse effects by Phenothiazines; Pharmacological effects of Benzodiazepines; Xylazine and horses
• Major Classes of CNS Drugs include Opioids, Tranquilizers, and Anticonvulsants.
• Tranquilizers include Chlorpromazine, Acepromazine (ACE), Propromazine, Triflupropromazine, Diazepam (Valium R), Midazepam, Clonazepam, Zolazepam, Alprazolam (Xanax R), Xylazine, Medetomidine, Dexmedetomidine (Dexdomitor R), Detomidine, Clonidine, and Butyrophenone derivatives.
• Unconventional Drugs include Phenytoin, Valproic Acid, Potassium Bromide, Gabapentin, Levetiracetam, Felbamate, Zonisamide.
• Opioids include Luminal, Morphine, and Fentanyl.
• Butyrophenone derivatives block D2 receptors and include Azaperone, Droperidol, Morphine, Oxymorphone, Fentanyl, Carfentanil.
• Antiemetics review: Emesis is caused by the Chemoreceptor Trigger Zone (CTZ), Vomiting Center (VC), and Vestibular system.
• Barbiturates include Phenobarbital and Primidone.
• Anticonvulsants are a major class of CNS drugs and their major classes and their mechanisms of action should be reviewed.
• Injectable Anesthetics include Barbiturates, Non-barbiturates, and Dissociative agents.
• Antiemetics are a major class of CNS drugs and their major classes and their mechanisms of action should be reviewed.
• Antiemetic Drugs are classified into receptor antagonists, such as Cerenia.
• Therapeutic Emesis can be induced by Apomorphine, a D2-agonist, or Xylazine, an α2-agonist.
• Reversables include Yohimbine (xylazine), Atipamezole (medetomidine), Cerenia, Ondansetron (Zofran), Granisetron, Metoclopramide (Reglan), Domperidone, Chlorpromazine, Droperidol, Aprepitant, Diphenhydramine (Benadryl), Dimenhydrinate (Gravol), Hyoscine (Hysomide), Dicyclomine, Lorazepam, Diazepam, Midazolam, Nabilone, and Dronabinol.
• Opioids include Morphine and Bitorphanol.
• Major Classes of CNS Drugs include Antiemetics, L16.
• Tranquilizers include Acepromazine.
• Drugs for therapeutic emesis include Apomorphine, which is used in dogs and cats.
• Neuroleptanalgesia is an analgesic and tranquilizer combination, with α2-Agonists Xylazine and Detomidine, and Anticholinergic agents Atropine.
• Pre-anesthetics include Acepromazine, BDZs (GABA A), Baclofen (GABA B), Tizanidine, Guaifenesin, and "Triple Drip" Baclofen.
• Dissociatives include Ketamine.