NCM106 Pharmacology Topic 3 PDF

NCM106: PHARMACOLOGY TOPIC 3: DRUG AFFECTING THE NERVES AND THE NERVOUS SYSTEM 2nd YEAR, 1st SEMESTER | MISTERMS By: Ebora, Denise Holly Marie Drugs affecting the Nerves and the Nervous HISTAMINE (sleep-wake cycle...

NCM106: PHARMACOLOGY TOPIC 3: DRUG AFFECTING THE NERVES AND THE NERVOUS SYSTEM 2nd YEAR, 1st SEMESTER | MISTERMS By: Ebora, Denise Holly Marie Drugs affecting the Nerves and the Nervous HISTAMINE (sleep-wake cycle) System GLUTAMATE (need for making GABA) GLYCINE (motor and sensory function) Role of the Nervous System SUBSTANCE P (pain signaling) Controlling the functions of the human body. and many neuropeptides. Analyzing incoming stimuli. 2. Receptors for neurotransmitters are the Integrating internal and external responses. site of action for exogenous drugs. Central Nervous System (CNS): a. THE NEUROTRANSMITTER—receptor complex Composed of the brain and spinal cord. may directly alter the permeability of the cell membrane by opening or closing specific ion Peripheral Nervous System (PNS): channels. b. SECOND MESSENGERS. The neurotransmitter- Sensory receptors bring information into the receptor complex may initiate a sequence of CNS chemical reactions that alter ion transport Motor nerves carry information away from the across the membrane, thereby altering the CNS membrane potential. Specific intracellular signal molecules, or second messengers, may be Autonomic Nervous System (ANS): generated. The second messenger system Uses components of the CNS and PNS to sustains and amplifies the cellular response to regulate automatic or unconscious responses drug—receptor binding. The vast majority of to stimuli. these neurotransmitters have G protein- coupled receptors (GPCRs). INTRODUCTION Blood—brain barrier (BBB) Drugs can alter the function of the central nervous system (CNS) to provide: Circulating drugs must cross BBB in order to gain access to the neurons of the brain. 1. Analgesic-antipyretics 2. Anti-Inflammatory drugs 1. Drugs that are cross BBB most readily: 3. General and local anesthetics, hypnotics, a. lipid soluble, sedatives (muscle relaxants) b. small in molecular size, 4. Anti-migraine c. poorly bound to protein, 5. Narcotics and controlled drugs d. nonionized at the pH of cerebrospinal fluid (CSF) Neurotransmitter—receptor relationship 2. The BBB tends to increase in permeability in the presence of inflammation or at the site of Neurotransmitters released by a presynaptic neuron tumors. combine with receptors on the plasma membrane 3. The BBB is poorly developed in neonates; of a postsynaptic neuron, altering its membrane hence, chemicals can easily gain access to the potential. neonatal brain. 1. Neurotransmitters in the CNS include: DOPAMINE (happy hormone) Y-AMINOBUTYRIC ACID (GABA) (calming hormone) ACETYLCHOLINE (Ach) (memory, motivation, arousal, attention) NOREPINEPHRINE (noradrenaline – arousal, attention, stress reaction) SEROTONIN (feel-good hormone) NCM106: PHARMACOLOGY TOPIC 3: DRUG AFFECTING THE NERVES AND THE NERVOUS SYSTEM DRUGS Non opioid analgesics are mostly used for mild to moderate pain. ANALGESICS - ANTIPYRETICS - ANTI Opioid analgesics are used for severe pain. INFLAMMATORY PAIN RECEPTOR PAIN & FEVER Free nerve endings located in various body PAIN: Pain is a symptom of inflammation tissues responding to thermal, mechanical, FEVER: When the temperature is above 100.4 F/ 38 chemical stimuli C Injured tissue releases chemicals Prostaglandins & Leucotrienes that make pain ANALGESIC: A drug that selectively relieves pain by receptor more sensitive acting on CNS or on peripheral pain mechanisms without significantly altering consciousness. PHYSIOLOGY OF PAIN ANTIPYRETIC: A drug that reduces fever by lowering body temperature PAIN The means by which the body is made aware of the presence of tissue damage. There are two components of pain: o Perception is the process by which pain is recognized by the brain o Reaction is any involuntary act occurring in response to a stimulus causing sharp pain TYPES OF PAIN: Source (injury/inflammation/heat/Cold) 1. ACUTE – Sudden, unexpected; Triggers “fight- Pain Receptors or-flight” response. Ex: Fracture, Trauma, Soft Discharge impulse Tissue Injury. Electrical activity to spinal cord and brain 2. CHRONIC – Pain that lasts longer than the In brain: electrical activity becomes expected healing time. Ex: Chronic Joint Pain, experienced of pain Arthritis, Cancer-related Pain, Back Pain 3. SOMATIC – Pain in tendons, nerves, bones, INFLAMMATION vessels. Ex: Tear in a tendon, crowning during Inflammation is the complex labor. pathophysiological response of vascularized 4. VISCERAL - Pain felt “in the organs” ; “Viscera” tissue to injury = internal organs. Ex: Cancer or long-term The injury may result from various stimuli, illness. including thermal, chemical, or physical 5. NEUROPATHIC – Pertaining to the nerves. Ex: damage; ischemia; infectious agents and Diabetic patients (Diabetic Neuropathy) antigen-antibody interactions PAIN MEASUREMENT SCALE 5 CARDINAL SIGNS OF INFLAMMATION NCM106: PHARMACOLOGY TOPIC 3: DRUG AFFECTING THE NERVES AND THE NERVOUS SYSTEM Classifications of Analgesics OPIOIDS: Morphine & morphine-like substance NON-OPIOIDS: NSAIDS, ACETAMINOPHEN PAG = periaqueductal gray; RVM = rostral ventromedial medulla MECHANISM OF ACTION All opioid receptors are G-protein coupled receptors and inhibit adenylate cyclase. They are also involved in: o Post synaptic receptor activation- OPIOIDS Increasing K+ Efflux -increases hyperpolarization. OPIOIDS ANALGESICS o Pre synaptic receptor activation- Reducing presynaptic CaVT influx Thusinhibitst Opioids are narcotic analgesics that relieve pain by neuronal activity. binding to opioid receptors, which are present in the central and peripheral nervous system. It can cause CLASSIFICATION OF OPIOIDS numbness and induce a state of unconsciousness. 1. OPIOID AGONIST Natural opium alkaloid: ex Morphine, Codeine Semisynthetic opiates: ex Oxymorphone Synthetic opioids: ex Pethidine, Tramadöl, Methadone, Fentanyl, Remifentanil a. OPIOID AGONIST | MORPHINE MOA: Opioid drugs, typified by morphine, produce their pharmacological actions, including analgesia, by acting on receptors located on neuronal cell membranes. The presynaptic action of opioids to inhibit neurotransmitter release is considered to be ***mu (μ), kappa (κ), and delta (δ) their major effect in the nervous system. USES: 1. This medication is used to treat severe pain. 2. Morphine belongs to a class of drugs known as opioid analgesics. 3. It works in the brain to change how your body feels and responds to pain. NCM106: PHARMACOLOGY TOPIC 3: DRUG AFFECTING THE NERVES AND THE NERVOUS SYSTEM b. OPIOID AGONIST | CODEINE f. SYNTHETIC OPIOID | TRAMADOL MOA: Codeine is an opioid and an agonist of the mu MOA: Tramadol is a centrally-acting analgesic with a opioid receptor. It acts on the central nervous multimode of action. It acts on serotonergic and system to have an analgesic effect. It is metabolized noradrenergic nociception, while its metabolite O- in the liver to produce morphine which is ten times desmethyltramadol acts on the u-opioid receptor. Its more potent against the u receptor. analgesic potency is claimed to be about one-tenth that of morphine. USES: USES: Tramadol (a schedule IV drug in the US) is 1. Codeine is used to treat mild to moderate used primarily to treat mild to severe pain, both pain and to relieve coughing. acute and chronic. There is moderate evidence for 2. It also treats diarrhea and diarrhea- use as a second-line treatment for fibromyalgia but predominant irritable bowel syndrome. is not FDA approved for this use. 3. It is a weak analgesic. 4. It is used in combination with paracetamol g. SYNTHETIC OPIOID | METHADONE or with ibuprofen to relieve pain MOA: Methadone hydrochloride is a u-agonist; a c. OPIOID AGONIST | HYDROMORPHONE synthetic opioid analgesic with multiple actions (DIHYDROMORPHINONE) qualitatively similar to those of morphine, the most prominent of which involves the central nervous MOA: It is an opioid agonist that binds to several system and organs composed of smooth muscle. opioid receptors. Its analgesic characteristics are through its effect on the mu-opioid receptors. It also Uses: The principal therapeutic uses for methadone acts centrally at the level medulla, depressing the are for analgesia and for detoxification or respiratory drive and suppressing cough. maintenance in opioid addiction. The methadone abstinence syndrome, although qualitatively similar USES: An opioid analgesic used to treat moderate to to that of morphine, differs in that the onset is severe pain when the use of an opioid is indicated. slower, the course is more prolonged, and the d. OPIOID AGONIST | OXYMORPHONE symptoms are less severe. MOA: An opioid analgesic with actions and uses h. SYNTHETIC OPIOID | REMIFENTANIL similar to those of morphine, apart from an absence MOA: a specific u-receptor agonist of cough suppressant activity. USES: Remifentanil is used as an opioid analgesic USES: It is used in the treatment of moderate to that has a rapid onset and rapid recovery time. It severe pain, including pain in obstetrics has been used effectively during craniotomies, e. SYNTHETIC OPIOID | PETHIDINE spinal surgery, cardiac surgery, and gastric bypass surgery.While opiates function similarly, with MOA: Pethidine is often employed in the treatment respect to analgesia, the pharmacokinetics of of post-anesthetic shivering. The pharmacologic Remifentanil allow for quicker post- operative mechanism of this anti-shivering effect is not fully recovery. understood, but it may involve the stimulation of K- opioid receptors. i. SYNTHETIC OPIOID | FENTANYL USES: MOA: It is a u-agonist. It has a high lipophilic character and can easily crosses the brain barrier 1. Pethidine is the most widely used opioid and enters central Nervous system. in labour and delivery but has fallen out of favor. USES: 2. Pethidine is the preferred painkiller for 1. It is opioid analgesic. It is about 80 times diverticulitis, because it decreases more active than Morphine. intestinal intraluminal pressure. 2. It is given in combination with general analgesthetics to produce surgical analgesic. NCM106: PHARMACOLOGY TOPIC 3: DRUG AFFECTING THE NERVES AND THE NERVOUS SYSTEM 3. It helpful in maintaining the state of NON-OPIOIDS neuroleptanalgesla NONOPIOID (nonnarcotic) ANALGESICS 2. OPIOID AGONIST-ANTAGONIST relieve pain with only a minor alteration of a. OPIOID AGONIST-ANTAGONIST | consciousness PENTAZOCINE safer than opioids, produce fewer side effects, and are not addicting MOA: It is believed to work by activating (agonizing) act principally at the peripheral nerve endings K-opioid receptors (KOR) and blocking (antagonizing) inhibit the synthesis of prostaglandins, which u-opioid receptors. occurs at sites of tissue inflammation and USES: produce their analgesic effects peripherally and their antipyretic effect centrally 1. Primarily to treat pain, although its analgesic effects are subject to a ceiling NSAIDS (non-steroidal anti-inflammatory drugs) effect. /nonnarcotics/ aspirin like analgesics Non opioid *It has been discontinued by its corporate analgesics which alleviate pain by reducing local sponsor in Australia, although it may be inflammatory responses. In contrast. the anti- available through the special access inflammatory compounds are used for short-term scheme pain relief and for modest pain, such as that of headache, muscle strain, bruising, or arthritis. 3. PARTIAL RECEPTOR AGONIST Principal Pharmacologic Actions a. PARTIAL RECEPTOR AGONIST| BUPRENORPHINE 1. Analgesia – loss of sensation of pain that results from an interruption in the nervous MOA: Buprenorphine is a partial agonist at the mu system pathway between sense organ and receptor, meaning that it only partially activates brain opiate receptors. It is also a weak kappa receptor 2. Antipyresis– reduction in body temperature in antagonist and delta receptor agonist. It is a potent case of hyperthermia analgesic that acts on the central nervous system 3. Anti-inflammatory – the inihibition of (CNS). prostaglandin synthesis leads to decreased redness and swelling of the inflamed area USES: Used to treat opioid use disorder, acute pain, and chronic pain. It can be used under the tongue *Of these actions the salicylates and NSAIDs exhibit all (sublingual), in the cheek (buccal), by injection three in therapeutically useful amounts, acetaminophen (intravenous) as a skin patch (transversal), or as an exhibits only analgesia and antipyresis. implant. 1. SALICYLATES 4. RECEPTOR AGONIST Came from the extracts Of willow bark containing a. RECEPTOR AGONIST| NALTREXONE the bitter glycoside salicin: MOA: relatively pure and long-lasting opioid 1. Acetylsalicylic acid (Aspirin, Bayer, A.S.A.) antagonist 2. Sodium salicylate (Uracel) 3. Magnesium salicylate (Mobidin, Doan's pills) USES: Naltrexone belongs to a class of drugs known 4. Salsalate (Disalcid, Monogesic) as opiate antagonists. It works in the brain to 5. Salicylamide (Uromide) 6. Diflunisal (Doloboid) prevent opiate effects (e.g., feelings of well-being, 7. Methylsalicylate (oil of wintergreen) pain relief). It also decreases the desire to take 8. Salicylic acid (Salacid, Freezone) opiates. This medication is also used to treat alcohol abuse. a. SALICYLATES | ACETYLSALICYLIC ACID (ASPIRIN) most widely employed drug in medical and dental practice. Described as the prototype salicylate NCM106: PHARMACOLOGY TOPIC 3: DRUG AFFECTING THE NERVES AND THE NERVOUS SYSTEM Ascriptin, Aspro, Bayer, Bex, Bufferin, Disprin, Dimness of vision Ecotrin, Entrophen, Halfprin, Novasen, Solprin, & Spren. *The lethal adult dose of aspirin is between 10 and 30 gm (30 to 100 of the 5-grain tablets) USES: 2. NSAIAS (NONSTEROID 1. Treatment of mild to moderate pain ANTIINFLAMMATORY AGENTS) (headache, migraine, backache, toothache, dysmenorrhea) Inhibit the enzyme cyclooxygenase, resulting in a 2. In control of fever reduction in the formation of prostaglandin 3. Treatment of rheumatic fever and arthritis precursors and thromboxanes from arachidonic 4. Treatment of thromboembolic disorders acid. 5. Treatment of transient ischemic attacks in CHEMICAL CLASSIFICATIONS: men 6. Treatment in post-MI 1. Propionic Acid Derivatives (Ibuprofen, Fenoprofen, Suprofen, Naproxen, Naproxen PHARMACOLOGIC EFFECTS sodium, Ketoprofen, Benoxaprofen 2. Acetic Acid Derivatives (Indomethacin, Sulindac, 1. Analgesia Tolmetin) 2. Antipyresis 3. Fenamic Acid Derivatives (Meclofenemate, 3. Anti-inflammatory Mefenamic acid) 4. Uricosuric effect-Large doses of aspirin 4. Pyrazolones (Phenylbutazon (over 5gm/24 hr) increase uric acid ,Oxyphenbutazone) 5. Oxicams (Piroxicam) secretion and decrease plasma urate 6. Salicylates (Diflunisal) concentrations. Smaller doses of aspirin (I- 2gm/24hr ) may decrease the secretion of PHARMACOKINETIS: uric acid and elevate the plasma urate concentration The NSAIAs peak in usually 1 to 2 hours 5. Platelet effect They are metabolized in the liver and excreted by the kidney. ADVERSE EFFECTS Fecal excretion occurs with fenamic acids, piroxicam, sulindac, an tolmetin. 1. GI effects: dyspepsia, N/V, GIT bleeding, ulcer Food can reduce the rate absorption but oral 2. Hypoprothrombinemia– after long term antacids have minimal or no effect on the rate use absorption 3. Thyroid-stimulating effect– elevated free USES: thyroid hormone in the blood 4. Metabolic effect– blood sugar may be 1. osteoarthritis, rheumatoid arthritis, gouty elevated or lowered arthritis 5. Hepatic and renal effects- hepatotoxicity 2. Fever 6. Effects on pregnancy- prolonged 3. Dysmenorrhea gestation, inc. risk of hemorrhage in 4. Pain mother and newborn, inc. risk of stillbirth or neonatal death, dec. birthweight PHARMACOLOGIC EFFECTS: TOXICITY: 1. Analgesia 2. Antipyresis *Salicylism– mild toxic reaction produced by 3. Antiinflammatory salicylates 4. Antigout 5. Dysmenorrhea S/SX: ADVERSE EFFECTS: Tinnitus Headache 1. GI effects: pain, bleeding leading to tarry Nausea and vomiting stool, irritation, ulceration Dizziness 2. Renal effects: renal failure, cystitis, increased incidence of UTI NCM106: PHARMACOLOGY TOPIC 3: DRUG AFFECTING THE NERVES AND THE NERVOUS SYSTEM 3. CNS effects: sedation, dizziness, It enhances water transport in kidney. confusion, mental depression, headache, vertigo, convulsion NARCOTICS AND ANTIMIGRAINE AGENTS 4. Blood clotting PAIN 5. Other: muscles weakness, ringing ears, blurred vision Sensory and emotional experience associated with actual or potential tissue damage. a. NSAIAS | IBUPROFEN DRUGS USED TO RELIEVE PAIN: Theoldest member of the NSAIAs and has the most clinical experience Narcotics: Opium derivatives used to treat Rapidly absorbed orally, and food decreases many types of pain absorption, antacids have no effect Antimigraine drugs: Reserved for the Peak=1-2hr; half-life 2-4hr; duration=4-6hr treatment of migraine headaches USES: LOCATION OF OPIOID RECEPTORS: 1. Rheumatoid arthritis, osteoarthritis CNS 2. Primary dysmenorrhea Nerves in the periphery 3. Gout Cells in the gastrointestinal (Gl) tract 4. Mild-to-moderate pain, fever 1. NARCOTIC AGONISTS b. NSAIAS | MEFENAMIC ACID ACTION Metabolized in liver, excreted in urine and in breastmilk Act at specific opioid receptor sites in the CNS – Peak=2hr; half-life= 3-3 ½ hr Produce analgesia, sedation, and a sense of well-being USES: Usage 1. dysmenorrhea 2. inflammatory disease Antitussives and adjuncts to general anesthesia 3. Mild-to-moderate pain Indication 3. ACETAMINOPHEN Relief of severe acute or chronic pain a. ACETAMINOPHEN | PARACETAMOL; N- Preoperative medication ACETYL PARAAMINOPHENOL) Analgesia during anesthesia Specific individual indications depending Metabolized in liver, excreted by the kidneys on their receptor affinity Crosses the placenta and is also found in breast milk 2. NARCOTIC AGONISTS-ANTAGONISTS Rapidly and completely absorbed in the GIT: onset 10-30 min, peak ½- 2hr, duration 4-6 hr, a. BUPRENORPHINE (BUPRENEX): half-Iife 1-3 Treats mild to moderate pain USES: b. BUTORPHANOL (STADOL, STADOL NS) 1. Mild-to-moderate pain (inhibition of Preoperative medication prostaglandin synthesis in the CNS) 2. Fever Relieves moderate to severe pain ADVANTAGES: c. NALBUPHINE (NUBAIN) Therapeutic doses have no effect on Treats moderate to severe pain cardiovascular and respiratory system. Adjunct for general anesthesia It does not produce gastric bleeding. Relieves pain during labor and delivery It does not affect platelet adhesiveness or affect uric acid excretion. NCM106: PHARMACOLOGY TOPIC 3: DRUG AFFECTING THE NERVES AND THE NERVOUS SYSTEM d. PENTAZOCINE (TALWIN) Preferred drug for patients switched from parenteral to oral forms after surgery or labor. 3. NARCOTIC ANTAGONISTS a. NALMEFENE (REVEX) Reverses the effects of narcotics; manages known or suspected narcotic overdose MIGRAINE HEADACHES: Severe, throbbing headaches on one side of the head. b. NALOXONE (NARCAN) CLUSTER HEADACHES: Begin during sleep; involve Reverses adverse effects of narcotics; sharp, steady eye pain, sweating, flushing, tearing, diagnoses suspected acute narcotic and nasal congestion. overdose. TENSION HEADACHES: Usually occur at times of c. NALTREXONE (RE VIA) stress; dull band of pain around the entire head Used orally in the management of alcohol 1. Migraine Treatments or narcotic dependence Ergot derivatives: cause constriction of cranial blood vessels and decrease the pulsation of cranial EVALUATION OF THE PATIENT TAKING NARCOTIC arteries. ANTAGONIST: a. ERGOTAMINE Monitor patient response to the drug (reversal Indications: Prevention or abortion of vascular of opioid effects, treatment of alcohol headaches dependence) Monitor for adverse effects (CV changes, Actions: Constricts cranial blood vessels, decreases arrhythmias, hypertension) pulsation of cranial arteries, and decreases Evaluate the effectiveness of the teaching plan hyperfusion of basilar artery vascular bed Monitor the effectiveness of comfort measures Sublingual route: Onset rapid; peak 0.5—3 h and compliance with the regimen Half-life: 2.7 h, then 21 h; metabolized in the liver, excreted in the feces TYPES OF HEADACHES GENERAL AND LOCAL ANESTHETIC AGENTS ANESTHESIA Reversible condition induced by anesthetic agent/drug that can cause deduction or complete loss of response to pain or other sensation such as consciousness or muscle movements during other invasive procedures that can be perform. CATEGORIES OF ANESTHETICS GENERAL ANESTHETICS Central nervous system (CNS) depressants used to produce loss of pain sensation and consciousness GOALS OF GENERAL ANESTHETICS Analgesia– loss of pain perception NCM106: PHARMACOLOGY TOPIC 3: DRUG AFFECTING THE NERVES AND THE NERVOUS SYSTEM Unconsciousness – loss of awareness of one’s RECOVERY surroundings Amnesia – inability to recall what took place Period from discontinuation of the anesthetic until the patient has regained consciousness RISK FACTORS ASSOCIATED WITH GENERAL ANESTHETICS Types of General Anesthetics 1. TYPES OF GENERAL ANESTHETICS | CNS factors BARBITURATE Cardiovascular factors Respiratory factors a. THIOPENTAL (PENTOTHAL) Renal and hepatic function Most widely used of the intravenous AGENTS INVOLVED IN BALANCED ANESTHESIA anesthetics Rapid onset of action; ultrashort recovery Preoperative medications period Sedative-hypnotics Antiemetics’s Indications: Induction of anesthesia, maintenance Antihistamines of anesthesia; induction of a hypnotic state narcotics Actions: Depresses the CNS to produce hypnosis STAGES OF GA ANESTHESIA and anesthesia without analgesia STAGE 1: THE ANALGESIA STAGE IV route: Onset 1 min; duration 20—30 min Stage of consciousness to unconsciousness. Half-time: 3—8 hours; metabolized in the liver, excreted in the urine STAGE 2: THE EXCITEMENT STAGE b. METHOHEXITAL (BREVITAL) Stage of depression, inhibiting the neurons in the CNS that leads to excitement, involuntary Rapid onset of action muscle movements, increase heart rate, blood Recovery period that is even more ultrashort pressure and respiration. A & B: Mechanism Of Action STAGE 3: SURGICAL ANESTHESIA The action of gen. anesthesia in the thalamus and RAS can lead to loss of Stage of gradual loss of muscle tone and consciousness reflexes, unresponsive to surgery and have The action in the hippocampus and regular breathing, vital stage of surgery and careful monitoring is necessary to prevent the prefrontal cortex can lead to Amnesia 4th stage overdose. The action in the spinal cord can lead to immobility and analgesia STAGE 4: MEDULLARY PARALYSIS Interaction to the neurotransmitter will cause the total effect of the drugs in this stage, the respiratory and cardiovascular failure occur, that can lead to death if client does not revive immediately 2. TYPES OF GENERAL ANESTHETICS | NON- BARBITURATE ADMINISTRATION OF GENERAL ANESTHETICS a. MIDAZOLAM (VERSED) INDUCTION Indications: Sedation, anxiolysis, and amnesia prior Period from the beginning of anesthesia until to diagnostic, therapeutic, or endoscopic stage 3, or surgical anesthesia, is reached procedures; induction of anesthesia; continuous MAINTENANCE sedation of intubated patients. Actions: Acts mainly at the limbic system and RAS; Period from stage 3 until the surgical procedure potentiates the effects of GABA; has little effect on is complete cortical function; exact mechanism of action is not understood NCM106: PHARMACOLOGY TOPIC 3: DRUG AFFECTING THE NERVES AND THE NERVOUS SYSTEM Route: Oral, IM, IV SEDATION Half-time: 1.8—6.8 hours; metabolized in the liver, Loss of awareness and reaction to environmental excreted in the urine stimuli 3. TYPES OF GENERAL ANESTHETICS | HYPNOSIS ANESTHETIC GASES Extreme sedation resulting in further CNS a. Nitrous oxide (blue cylinder) depression and sleep Prototype anesthetic gas Types of Anxiolytic and Hypnotic Agents b. Cyclopropane (orange cylinder) ANXIOLYTICS Has a rapid onset of action and a rapid Prevent feelings of tension or fear recovery SEDATIVES c. Ethylene (red cylinder) Calm and makep atients unaware of the Less toxic than most of the other gas environment anesthetics HYPNOTICS 4. Types of General Anesthetics | Volatile Liquids Cause sleep Halothane (Fluothane), Desflurane (Suprane), MINOR TRANQUILIZERS Enflurane (Ethrane), Isoflurane (generic), Methoxyflurane (Penthrane), & Sevoflurane Produce a state of tranquility in anxious patients (Ultane) DRUGS Indications: Induction and maintenance of general 1. BENZODIAZEPINE | DIAZEPAM (VALIUM) anesthesia Indications: Anxiety disorders, acute alcohol Actions: Depresses the CNS, causing anesthesia; withdrawal, muscle relaxation, tetanus, antiepileptic relaxes muscles; sensitizes the myocardium to the adjunct in status epilepticus, preoperative relief of effects of norepinephrine and epinephrine anxiety and tension Inhaled route: Onset rapid; peak rapid; duration end Actions: Acts in the limbic system and reticular of inhalation formation to potentiate the effects of GABA, an Half-time: Unknown; metabolized in the liver, inhibitory neurotransmitter; may act in spinal cord excreted in the urine and supraspinal sites to produce muscle relaxation LOCAL ANESTHETICS Routes: Oral, 1M, IV, rectal Used to cause loss of pain sensation and feeling Half-life: 20—80 hours, metabolized in the liver, in a designated area of the body. excreted in urine Does not produce the systemic effects Antidote: Fumazenil (Romazicon) associated with severe CNS depression. 2. BARBITURATES | PHENOBARBITAL ANXIOLYTIC AND HYPNOTIC AGENTS Indications: Sedation, insomnia, tonic—clonic States Affected by Anxiolytic and Hypnotic seizures and cortical focal seizures, emergency Drugs control of certain acute convulsive episodes, pre ANXIETY anesthetic Actions: Inhibits conduction in the ascending RAS; Feeling of tension, nervousness, apprehension, or depresses the cerebral cortex; alters cerebellar fear involving unpleasant reactions to a stimulus function; depresses motor output; can produce NCM106: PHARMACOLOGY TOPIC 3: DRUG AFFECTING THE NERVES AND THE NERVOUS SYSTEM excitation, sedation, hypnosis, anesthesia, and deep coma; and has anticonvulsant activity Routes: Oral, IM, IV, Sub-Q Half-life: 79 hours; metabolized in the liver, excreted in urine 3. OTHER ANXIOLYTIC AND HYPNOTIC DRUGS a. PARALDEHYDE (PARAL): Sedates patients with delirium tremens or psychiatric conditions characterized by extreme excitement. b. MEPROBAMATE (MILTOWN): Manages acute anxiety for up to 4 months. c. CHORAL HYDRATE (AQUACHLORAL): Produces nocturnal sedation or preoperative sedation. d. GLUTETHIMIDE (GENERIC), ZALEPLON (SONATA), AND ZOLPIDEM (AMBIEN): Short-term treatment for insomnia. e. ANTIHISTAMINES (PROMETHAZINE [PHENERGAN], DIPHENHYDRAMINE [BENADRYL]): Preoperative medications and postoperative to decrease the need for narcotics. f. BUSPIRONE (BuSpar): Reduces the signs and symptoms of anxiety without severe CNS and adverse effects.