Anesthetics, Analgesics, and Narcotics
-
Upload
crimea-state-medical-university-named-after-s-i-georgievsky -
Category
Health & Medicine
-
view
63 -
download
1
Transcript of Anesthetics, Analgesics, and Narcotics
Chapter 6 Topics
• Divisions of the Nervous System• Major Neurotransmitters• Anesthesia
– General Anesthesia– Local 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 System1. 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 SystemInvoluntary activities: respiration, circulation, digestion, sweating
Review
The nervous system has two components. What are they?
Answer – Central nervous system (CNS)– Peripheral nervous system (PNS)
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
• DopamineActs 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?
Answer – Alpha– Beta-1– Beta-2
Types of Receptors
• AlphaVasoconstriction, raise BP
• Beta-1Heart stimulation
• Beta-2Vasodilation 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.
– Alcohol
– Drugs– Ice for numbing– Blow to the head– Strangulation
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
– Adequate Muscle Relaxation
– Adequate Ventilation
Anesthesia
Goals of Balanced Anesthesia– Amnesia
– Adequate Muscle Relaxation
– Adequate Ventilation
– Pain Control
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
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 AnesthesiaDispensing 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
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 AgentsDispensing 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
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?
Answer – Esters– Amides
Local Anesthesia
Esters– Short acting– Metabolized in the plasma and tissue fluids– 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?
Answer– Pain perception– Temperature– Touch sensation– Proprioception– Skeletal muscle tone
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.
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 PainSource Area
InvolvedCharacteristics Treatment
Somatic body framework
throbbing, stabbing
narcotics, NSAIDS
Visceral kidneys, intestines, liver
aching, throbbing, sharp, crampy
narcotics, NSAIDS
Neuropathic Nerves burning, 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?
Answer – Analgesia– Sedation– Euphoria and Dysphoria
Pain Management
Effects of Narcotics
• AnalgesiaReduce pain from most sources
• SedationDecrease anxiety and cause drowsiness
Pain Management
Effects of Narcotics • Analgesia
Reduce pain from most sources
• SedationDecrease 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 painAdminister acetaminophen (APAP) or an NSAID
Pain Management
Analgesic Ladder
1. Onset of mild to moderate painAdminister acetaminophen (APAP) or an NSAID
2. Adequate relief is not achieved in Step 1Administer 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 1Administer NSAID plus a “weak” opioid (codeine)
3. Adequate relief is not achieved in Step 2Administer a strong opioid (morphine)
Pain Management
• DependencePhysical and emotional reliance on a drug
• AddictionCompulsive 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
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 AnalgesicDispensing 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
AuraSubjective 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 ReliefHeadache generally dissipates in six hours, but may last one to two days
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 triggersEx: red wine, caffeine, certain foods, bright lights
• If attacks are still frequent, drug therapy may be indicated
Discussion
Migraine therapy can be divided into two drug classes. What are they?
Answer – Prophylactic Therapy– Abortive Therapy
Migraine Headaches
• Prophylactic TherapyAttempts to prevent or reduce recurrence
• Abortive Therapy
Migraine Headaches
• Prophylactic TherapyAttempts 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 AgentsDispensing 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