Chapter 6 Anesthetics, Analgesics, and Narcotics

Chapter 6 Topics Divisions of the Nervous System Major Neurotransmitters Anesthesia –General AnesthesiaGeneral Anesthesia –Local AnesthesiaLocal Anesthesia Pain Management Migraine Headaches

Learning Objectives Understand the central and peripheral nervous systems, their functions, and their relationship to drugs. Become aware of the role of neurotransmitters. Learn how drugs affect body systems and where they work in the body. Understand the concepts of general and local anesthesia, and know the functions of these agents.

Learning Objectives Define the action of neuromuscular blocking agents in reducing muscle activity. Distinguish between narcotic and nonnarcotic analgesia. Become familiar with the various types of agents for migraine headaches.

Divisions of the Nervous System Central Nervous System –Brain –Spinal cord Peripheral Nervous System –Nerves –Sense organs

Divisions of the Nervous System Central Nervous System 1.Brain receives information 2.Evaluates information 3.Sends out a response Peripheral Nervous System

Divisions of the Nervous System Central Nervous System Peripheral Nervous System –Somatic Nervous System –Autonomic Nervous System

Divisions of the Nervous System Central Nervous System Peripheral Nervous System –Somatic Nervous System Voluntary action: skeletal muscle contraction and movement –Autonomic Nervous System Involuntary activities: respiration, circulation, digestion, sweating

Autonomic Nervous System

Review The nervous system has two components. What are they?

Review The nervous system has two components. What are they? Answer –Central nervous system (CNS) –Peripheral nervous system (PNS)

Major Neurotransmitters Acetylcholine GABA Dopamine Epinephrine Serotonin

Major Neurotransmitters Acetylcholine (ACh) –Smooth muscle, cardiac muscle, and exocrine glands –Anticholinergics block ACh receptors GABA Dopamine Epinephrine Serotonin

Major Neurotransmitters Acetylcholine GABA (gamma-aminobutyric acid) Regulates message delivery system of the brain Dopamine Epinephrine Serotonin

Major Neurotransmitters Acetylcholine GABA Dopamine Acts on the CNS and kidneys Epinephrine Serotonin

Major Neurotransmitters Acetylcholine GABA Dopamine Epinephrine –Acts on cardiac and bronchodilator receptors –Known as Adrenaline Serotonin

Major Neurotransmitters Acetylcholine GABA Dopamine Epinephrine Serotonin –Acts on smooth muscle and gastric mucosa (causes vasoconstriction) –Emotional responses: depression, anxiety

Communication by Neurotransmitters Neurotransmitters are released from one axon and received by another neuron’s dendrites.

Discussion What are three important types of receptors in the study of drugs?

Discussion What are three important types of receptors in the study of drugs? Answer –Alpha –Beta-1 –Beta-2

Types of Receptors Alpha Vasoconstriction, raise BP Beta-1 Heart stimulation Beta-2 Vasodilation and bronchodilation

Drug Effects on Receptors Drugs can have two types of effects on receptors. –Stimulating, causing a reaction –Blocking, preventing a reaction Dopamine blocking Anticholinergics

Anticholinergic Side Effects Decreased GI motility Decreased sweating Decreased urination Dilated pupils Dry eyes Dry mouth

Anesthesia In the “old days” the following were used for anesthesia.

Anesthesia In the “old days” the following were used for anesthesia. –Alcohol –Drugs –Ice for numbing –Blow to the head –Strangulation

Anesthesia Now, anesthesia is designed to focus on specific systems, such as

Anesthesia Now, anesthesia is designed to focus on specific systems, such as Nervous system Skeletal system Respiratory system GI system Endocrine system Hepatic system Cardiovascular system

Anesthesia Goals of Balanced Anesthesia –Amnesia

Anesthesia Goals of Balanced Anesthesia –Amnesia –Adequate Muscle Relaxation

Anesthesia Goals of Balanced Anesthesia –Amnesia –Adequate Muscle Relaxation –Adequate Ventilation

Anesthesia Goals of Balanced Anesthesia –Amnesia –Adequate Muscle Relaxation –Adequate Ventilation –Pain Control

Types of Anesthesia General Local

Types of Anesthesia General Local

Discussion What are some of the indicators used to assess general anesthesia?

Discussion What are some of the indicators used to access general anesthesia? Answer: Blood pressure, hypervolemia, oxygen level, pulse, respiratory rate, tissue perfusion, urinary output

General Anesthesia Preanesthetic Medications –Control sedation –Reduce postoperative pain –Provide amnesia –Decrease anxiety

General Anesthesia Malignant Hyperthermia –Side effect of anesthesia Fever of 110°F or more Life threatening –Treatment: dantrolene (Dantrium) Always check expiration date. Warning!

Inhalant Anesthetics desflurane (Suprane) enflurane (Ethrane) halothane isoflurane (Forane) nitrous oxide Drug List

Inhalant Anesthesia Side Effects Causes reduction in blood pressure May cause nausea and vomiting

nitrous oxide Causes analgesia only; no amnesia or relaxation May be given alone or may be given with more powerful anesthetics to hasten the uptake of the other agent(s) Commonly used for dental procedures Rapidly eliminated

desflurane (Suprane) Has rapid onset and recovery Often used in ambulatory surgery

General Anesthesia Often dispensed by IV drip Very lipid soluble

Injectable Anesthetics etomidate (Amidate) fentanyl (Duragesic, Sublimaze) fentanyl-droperidol ketamine (Ketalar) morphine propofol (Diprivan) sufentanil (Sufenta) Drug List

Injectable Anesthetics Barbituates –methohexital (Brevital) –thiopental (Pentothal ) Benzodiazepines –diazepam (Valium) –lorazepam (Ativan) –midazolam (Versed) Drug List

propofol (Diprivan) Used for maintenance of anesthesia, sedation, or treatment of agitation Has antiemetic properties –Drowsiness –Respiratory depression –Motor restlessness –Increased blood pressure

Injectable Anesthesia Dispensing Issues Diprivan (anesthetic) and Diflucan (antifungal) may be confused. This mix-up could be life-threatening. Warning!

fentanyl Dosage Forms –IV (Sublimaze) –patch (Duragesic) –lozenge (Actiq) for children Used extensively for open-heart surgery due to lack of cardiac depression

Benzodiazepines Used for induction, short procedures, and dental procedures Useful in controlling and preventing seizures induced by local anesthetics midozolam (Versed) –fastest onset of action –greatest potency –most rapid elimination

Antagonist Agents Antagonist agents reverse benzodiazepine and narcotic overdose.

Antagonist Agents flumazenil (Romazicon) nalmefene (Revex) naloxone (Narcan) Drug List

flumazenil (Romazicon) Antagonizes benzodiazepines by competing for receptor site Used for complete or partial reversal

naloxone (Narcan) Competes for opiate receptor sites Has a shorter duration of action than narcotics, so it must be given repeatedly

Neuromuscular Blocking Agents Causes immediate skeletal muscle relaxation. –Short Duration –Intermediate Duration –Extended Duration Used to facilitate endotracheal intubation. –Allows for easier insertion of endotracheal tube. –Keeps airway open.

Neuromuscular Blocking Agents atracurium (Tracrium) cisatracurium (Nimbex) mivacurium (Mivacron) pancuronium rocuronium (Zemuron) succinylcholine (Quelicin) vecuronium (Norcuron) Drug List

Neuromuscular Blocking Agents Dispensing Issues Very expensive Be conscious of storage requirements Store away from look-alike and drugs Warning!

succinylcholine (Quelicin) Often called “sux.” Only depolarizing agent. All others work as competitive antagonists to ACh receptors. Persistent depolarization at motor endplate. Causes sustained, brief period of flaccid skeletal muscle paralysis.

Reversal of Neuromuscular Blocking Agents Increases the action of acetylcholine by inhibiting acetylcholinesterase Used for reversal of nonpolarizing agents

Anticholinesterase Agents edrophonium (Enlon) neostigmine (Prostigmin) pyridostigmine (Mestinon) Drug List

Types of Anesthesia General Local

Local Anesthesia Relieves pain without altering alertness or mental function.

Local Anesthesia Variety of Dosage Forms –Topical –Superficial injection (infiltration) –Nerve block –IV –Epidural –Spinal

Discussion Local anesthetics are classified by their chemistry into two classes. What are they?

Discussion Local anesthetics are classified by their chemistry into two classes. What are they? Answer –Esters –Amides

Local Anesthesia Esters –Short acting –Metabolized in the plasma and tissue fluids –Excreted in urine

Local Anesthesia Amides –Longer acting –Metabolized by liver enzymes –Excreted in urine

Local Anesthesia Esters benzocaine (Americaine) chloroprocaine (Nesacaine) dyclonine (Cēpacol Maximum Strength) procaine (Novocain) tetracaine (Cēpacol Viractin, Pontocaine) Drug List

Local Anesthesia Amides bupivacaine (Marcaine) levobupivacaine (Chirocaine) lidocaine (L-M-X, Solarcaine, Xylocaine) lidocaine-epinephrine (Xylocaine w/ Epinephrine) lidocaine-prilocaine (EMLA) mepivacaine (Carbocaine) Drug List

Discussion What functions are lost with local anesthetics?

Discussion What functions are lost with local anesthetics? Answer –Pain perception –Temperature –Touch sensation –Proprioception –Skeletal muscle tone

Discussion Under what conditions would a local anesthetic be used over a general anesthetic?

Discussion Under what conditions would a local anesthetic be used over a general anesthetic? Answer: It is chosen when a well-defined area of the body is targeted.

Pain Management What is pain? –A protective mechanism to warn of damage or the presence of disease –Part of the normal healing process Managing pain can be a challenge.

Discussion What are the classifications of pain?

Discussion What are the classifications of pain? Answer –Acute –Chronic Nonmalignant Malignant

Pain Management Acute Pain Associated with trauma or surgery Easier to manage by treating the cause Has a beginning and an end

Pain Management Chronic Pain No end to the pain Patients may have a sense of helplessness and hopelessness Affects different aspects of life –Physical –Psychological –Social –Spiritual

Pain Management Chronic Nonmalignant Pain Cause may be diagnosed or undiagnosed Pain lasts for more than 3 months Patients may have signs and symptoms of depression

Pain Management Chronic Malignant Pain Accompanies malignant disease Often increases in severity with disease progression

Major Sources of Pain SourceArea Involved CharacteristicsTreatment Somaticbody framework throbbing, stabbing narcotics, NSAIDS Visceralkidneys, intestines, liver aching, throbbing, sharp, crampy narcotics, NSAIDS NeuropathicNervesburning, numbing, tingling antidepressants, anticonvulsants Sympathetically Mediated overactive sympathetic system no pain should be felt nerve blockers

Pain Management Narcotic Pain-modulating chemical derived from opium or is synthetically produced Also called opioid Causes insensibility or stupor Mainly effects on CNS and GI tract Lesser effects on peripheral tissues

Pain Management Natural Opioids Endorphins, enkephalins, and dynorphins Produced by the brain in response to pain stimuli When receptors are activated –causes decreased nerve transmission –sensation of pain is diminished Opioids bind to these same receptors

Discussion What are the three effects of narcotics?

Discussion What are the three effects of narcotics? Answer –Analgesia –Sedation –Euphoria and Dysphoria

Pain Management Effects of Narcotics Analgesia Reduce pain from most sources

Pain Management Effects of Narcotics Analgesia Reduce pain from most sources Sedation Decrease anxiety and cause drowsiness

Pain Management Effects of Narcotics Analgesia Reduce pain from most sources Sedation Decrease anxiety and cause drowsiness Euphoria and Dysphoria –Can cause feelings of well-being and disquiet or restlessness –Potential for tolerance and dependence

Pain Management Patient-Controlled Analgesia Pump –Patient controls (within limits) when and how often medication is administered –Allows for better pain control

Pain Management Analgesic Ladder 1. Onset of mild to moderate pain Administer acetaminophen (APAP) or an NSAID

Pain Management Analgesic Ladder 1. Onset of mild to moderate pain Administer acetaminophen (APAP) or an NSAID 2. Adequate relief is not achieved in Step 1 Administer NSAID plus a “weak” opioid (codeine)

Pain Management Analgesic Ladder 1. Onset of mild to moderate pain Administer acetaminophen (APAP) or an NSAID 2. Adequate relief is not achieved in Step 1 Administer NSAID plus a “weak” opioid (codeine) 3. Adequate relief is not achieved in Step 2 Administer a strong opioid (morphine)

Pain Management Chronic opioid therapy has a low risk of addiction when used appropriately.

Discussion What is the difference between addiction and dependence?

Pain Management Dependence Physical and emotional reliance on a drug Addiction Compulsive disorder

Pain Management Symptoms of Addiction Preoccupation with drugs Refusal of medication tapers Strong preference for a specific opioid Decrease in ability to function Medication is typically not taken as prescribed Have a tendency to visit many different doctors and pharmacies in order to get the drug(s)

Narcotic Dispensing Issues Pharmacy technicians have a legal and moral responsibility to alert pharmacist of suspected abuse and addiction. Warning!

Pain Management Patients are more successful overcoming addiction if withdrawal symptoms are handled appropriately.

Addiction Treatment buprenorphine (Buprenex, Subutex) buprenorphine-naloxone (Suboxone) methadone (Dolophine) Drug List

methadone (Dolophine) Uses –Detoxification –Maintenance of narcotic addiction Dispensed in clinics or in hospitals Binds to opiate receptors without giving a euphoric feeling

Discussion What are the pros and cons of methadone clinics?

Pain Management Combinations of narcotics and nonnarcotics is common. –Enhances relief –Facilitates use of lower doses –Decreases side effects

Pain Management Combinations can be dangerous if the ASA or APAP dose is overlooked. Technicians should be aware of this risk and assess each prescription for possible toxic doses. Warning!

Narcotic Analgesics Varying dose requirements due to –Severity of pain –Individual response to pain –Patient’s age and weight –Presence of concomitant disease

Narcotic Analgesics Many different dosage forms and strengths are available. Goal: Patient comfort Key to reaching goal: Constant reassessment Side effects should be anticipated and minimized for patient comfort

Narcotic Analgesic Side Effects –Mental confusion –Reduced alertness –Nausea/vomiting –Dry mouth –Constipation –Inflammatory process –Bronchial constriction

Narcotic Analgesics APAP-codeine (Tylenol With Codeine) hydrocodone-APAP (Lortab, Vicodin) hydromorphone (Dilaudid) meperidine (Demerol) morphine (MS Contin) oxycodone (OxyContin) Drug List

Narcotic Analgesics oxycodone-APAP (Endocet, Percocet, Tylox) oxycodone-ASA (Endodan, Percodan) oxymorphone (Numorphan) pentazocine (Talwin) pentazocine-naloxone (Talwin NX) propoxyphene (Darvon) propoxyphene-APAP (Darvocet-N 100) Drug List

Narcotic Analgesic Dispensing Issues Be careful of multiple strengths. Lortab and Lorabid can be confused. Pay attention to dosing schedule. Morphine sulfate and magnesium sulfate are often confused. Warning!

Migraine Headaches Migraine –Severe, throbbing, vascular headache –Recurrent unilateral head pain –Combined with neurologic and GI disturbances

Migraine Headaches 90% of migraine sufferers report nausea. Sensitivity to light, sound, and stimulation are also common.

Migraine Headaches Components of classic migraine (all five not experienced by every migraine sufferer): –Prodrome –Aura –Headache –Headache relief –Postdrome

Migraine Headaches Prodrome Symptom indicating the onset

Migraine Headaches Aura Subjective sensation or motor phenomenon that precedes and marks the onset of a migraine attack Flashing lights Shimmering heat waves Bright lights Dark holes in visual fields Blurred or cloudy vision Transient loss of vision

Migraine Headaches Headache and Headache Relief Headache generally dissipates in six hours, but may last one to two days

Migraine Headaches Postdrome Knowing the headache is gone

Migraine Headaches Serotonin appears to be involved in cause. –Decreased levels = excessive vasodilation in cranial arteries = headache. –By stimulating serotonin receptors, vasoconstriction will occur thereby alleviating the migraine.

Migraine Headaches Causative Factors Diet Stress Depression Sleep habits Certain medications Hormonal fluctuations Atmospheric changes Environmental irritants

Migraine Headaches Initial Treatment Identifying and eliminating triggers Ex: red wine, caffeine, certain foods, bright lights If attacks are still frequent, drug therapy may be indicated

Discussion Migraine drug therapy can be divided into two classes. What are they?

Discussion Migraine therapy can be divided into two drug classes. What are they? Answer –Prophylactic Therapy –Abortive Therapy

Migraine Headaches Prophylactic Therapy Attempts to prevent or reduce recurrence Abortive Therapy

Migraine Headaches Prophylactic Therapy Attempts to prevent or reduce recurrence Abortive Therapy –Treats acute migraine attacks –Taken after headache occurs, at first sign of a headache

Migraine Headaches Prophylactic Therapy –Anticonvulsants –Beta blockers –Calcium channel blockers –Estrogen –Feverfew –NASAIDs –SSRIs –Tricyclic antidepressants Abortive Therapy –Simple analgesics –NSAIDs –Ergotamine- containing medications –Other drugs

Migraine Headaches Triptans—Selective 5-HT Receptor Agonists almotriptan (Axert) eletriptan (Relpax) frovatriptan (Frova) naratriptan (Amerge) rizatriptan (Maxalt, Maxalt-MLT) sumatriptan (Imitrex) zolmitriptan (Zomig) Drug List

sumatriptan (Imitrex) Binds to serotonin receptors causing vasoconstriction of blood vessels in the dura Use at first sign of headache Available in injection, nasal spray, and tablet

rizatriptan (Maxalt-MLT) Sublingual tablet, quickly absorbed Has most rapid onset of action of all oral migraine therapies May receive relief after 30 minutes Maxalt is not absorbed as quickly as Maxalt-MLT

Migraine Headaches Ergot Preparations dihydroergotamine (D.H.E. 45, Migranal) ergotamine (Ergomar) ergotamine-caffeine (Cafergot) Drug List

Migraine Headaches Antiemetic Agents chlorpromazine (Thorazine) metoclopramide (Reglan) prochlorperazine (Compazine) Drug List

metoclopramide (Reglan) Reduces nausea and vomiting Enhances absorption of other antimigraine products Metoclopramide (Reglan) and aspirin have been prescribed together instead of using sumatriptan (Imitrex)

Migraine Headaches Opiod Analgesic butorphanol (Stadol, Stadol NS) Beta Blocker propranolol (Inderal) Drug List

butorphanol (Stadol, Stadol NS) Nasal spray is used more commonly than injection Has analgesic properties for moderate-to- severe pain Can be addictive and abused A controlled substance in some states

Migraine Headaches Other butalbital-APAP-caffeine (Fioricet) butalbital-ASA-caffeine (Fiorinal) isometheptene-dichloralphenazone-APAP (Midrin) tramadol (Ultram) Drug List

Migraine Agents Dispensing Issues Tramadol and Toradol could be confused. Be sure of which drug is being prescribed. Warning!

tramadol (Ultram) High success rate when given with NSAIDs (ibuprofen) Has slow onset of action Is not a controlled substance, but has shown potential for addiction

isometheptene-dichloralphenazine- acetaminophen (Midrin) Has fewer side effects than ergotamines, but may be less effective Combination of analgesic, sedative, and vasoconstrictor

Discussion What are some of the issues facing migraine sufferers and the medication that is used?

Discussion What are some of the issues facing migraine sufferers and the medication that is used? Answer –N/V –0.5-2 hour onset of action –side effects of medications