Week 7: Pain & Anesthetics Flashcards
Immediate goal of pain management
–Reduce pain to level that allows patient to:
perform reasonable ADLs
Key principles of pain management
–Patient should be considered_______of their pain.
–Pain management is a patient _______.
–Nonpharmacologic interventions _____________.
▪Combination of therapies optimal
–Patient should be considered expert of their pain.
–Pain management is a patient right.
–Nonpharmacologic interventions encouraged.
▪Combination of therapies optimal
Acute vs Chronic pain
▪Acute pain = Abrupt onset but brief duration
▪Chronic pain = persists longer than 6 months
–Chronic nonmalignant pain
–Chronic malignant = Cancer pain
Nociceptor vs Neuropathic pain
▪Nociceptor = Responds well to analgesics
–Somatic = Localized muscles or joints
–Visceral = Organs
▪Neuropathic = caused by Injury or irritation to nerve tissue
Phases of pain physiology
- _____________: trauma stimulates ____________
- Transmission in ___________________
- Transmission in ____________________
- ______________ [cerebral cortex recognizes the pain stimulus]
- ____________: limbic system reacts to pain
- Transduction: trauma stimulates nociceptors
- Transmission in peripheral nerves
- Transmission in spinal tracts
- Perception [cerebral cortex recognizes the pain stimulus]
- Modulation: limbic system reacts to pain
Nonpharmacologic therapies are used to attain adequate pain relief in place of drugs
– Serve as adjuncts to analgesics
Improved comfort, lower doses, potential for fewer drug related
adverse events
Examples:
▪Acupressure and acupuncture
▪Hypnosis, massage, meditation
▪Application of cold or heat
▪Biofeedback therapy & Electrical nerve stimulation
▪Distraction = Art/music therapy/ Laughter
▪Physical therapy
▪Yoga
Drug classes for pain meds
▪Nonopioids
–NSAIDs, centrally acting agents, or acetaminophen
–Used for mild to moderate pain
▪Opioid drugs
–Used to treat severe pain
▪Adjuvant analgesics
–Used to treat chronic pain that’s neuropathic in nature
Combination drugs for pain
–Opioid & nonopioid drugs
–Available as fixed-dose tablets or capsules
–Dose ceiling due to toxicities of nonopioid analgesic
▪Such as risk of acute liver failure when taking acetaminophen
–Common examples: ?
–Opioid & nonopioid drugs
–Available as fixed-dose tablets or capsules
–Dose ceiling due to toxicities of nonopioid analgesic
▪Such as risk of acute liver failure when taking acetaminophen
–Common examples: Endocet, Norco, Percocet
Management of cancer pain
–Radiation therapy
–Nerve blocks
▪Alcohol / other neurotoxic substance
▪Local anesthetics / steroid hormones
Patient-controlled analgesia
–Infusion pump allows patient to self-administer.
–May reduce anxiety of waiting for drug administration
–Morphine usually used.
–Requires patient be conscious and capable of understanding pump operation
Opium (Papaver somniferum)
–Extracted from unripe :
poppy plant seeds
Opiates
–Natural substances obtained from:
–Include:
–Natural substances obtained from opium
–Include morphine and codeine
Opioid
–Synthetic drug with _____________ activity
–Can be _________ or __________
–Synthetic drug with morphine-like activity
–Can be natural or synthetic
Opioids are usually used for:
moderate to severe pain
Opioids when used for prolonged periods at high doses, can cause :
physical and psychological dependence
Narcotic: _________________ drug used to alleviate pain
Morphine-like
3 common receptors that opioids work with:
Mu
Kappa
Delta
Opioid agonists activate ___________________ receptors
mu and kappa
Opioid antagonists block _______________ receptors
mu and kappa
Mixed opioid agonist-antagonists work on one receptor but :
block or have no effect on another
Opioids
–Neither lower threshold for pain at nociceptor level nor _________________1_____________________
–Alter _______2_________, emotional response
▪Patient knows pain exists, but it does not cause concern or anxiety.
1- slow/block transmission of pain impulse
2- perception
Opioids Cause CNS depression:
Sedation, euphoria, intense relaxation
Opioids side effects
– GI side effects
▪Nausea, vomiting, constipation
– Urinary retention
– Pruritus
– Respiratory depression
– Orthostatic hypotension
– Increased intracranial pressure (ICP)
– Risk of physical and psychological dependence
– Dizziness, hallucinations, anxiety
– Tolerance
Prototype drug: Morphine sulfate (Astramorph PF, Duramorph RF, Roxanol)
–Therapeutic classification-
–Pharmacologic classification-
–Therapeutic classification
▪Narcotic analgesic
–Pharmacologic classification
▪Opioid agonist
Prototype drug: Morphine sulfate (Astramorph PF, Duramorph RF, Roxanol)
–Therapeutic effects and uses
▪Acute and severe _______________
▪Off label
–Preanesthetic __________ and to calm severely agitated patients
–Relieve _________________________ associated with end-stage cancer, heart failure, or pulmonary edema
▪Acute and severe chronic pain
▪Off label
–Preanesthetic sedation and to calm severely agitated patients
–Relieve shortness of breath associated with end-stage cancer, heart failure, or pulmonary edema
Prototype drug: Morphine sulfate (Astramorph PF, Duramorph RF, Roxanol)
–Mechanism of action
▪Occupies mu and kappa receptor sites in brain and dorsal horn of spinal cord that alter release of afferent neurotransmitters
▪Alters perception of and emotional response to pain
▪Produces analgesia and euphoria
▪Mimics actions of endogenous endorphins
Prototype drug: Morphine sulfate (Astramorph PF, Duramorph RF, Roxanol)
–Adverse effects
-Black box warning
▪CNS depression
▪Respiratory depression
▪Constipation, nausea, vomiting
▪Urinary retention
▪Sedation, dizziness, anxiety, disorientation
▪Orthostatic hypotension
▪Pruritus with IV or epidural route
–Black box warning
▪Schedule II controlled substance with high
potential for physical and psychologic dependence
▪Extended release forms prescribed for opioid tolerant patients only and are not intended for prn use
Prototype drug: Morphine sulfate (Astramorph PF, Duramorph RF, Roxanol)
–Contraindications/precautions
▪Hypersensitivity
▪Premature infants
▪Precautions
–Older adults
–Undiagnosed abdominal pain
–Hepatic/renal impairment
–Shock
–CNS depression
–Head injury/increased ICP
–COPD
Morphine sulfate
–Drug interactions
▪Increased sedation
–CNS depressants
▪Reversed effect with opioid antagonist
–Naloxone
▪Additive constipation
–Antidiarrheal
Morphine sulfate
–Herbal/food
▪Kava, valerian, or chamomile can increase CNS depression
▪St. John’s wort may decrease analgesic action
Morphine sulfate Treatment of overdose
▪Overdose can cause coma & respiratory depression
–Immediate treatment
–Naloxone for morphine intoxication
Mixed agonist-antagonist opioids
–Fewer ________ effects
▪Less ___________ depression
▪Lower potential for dependence
–Used to treat ____________ pain
–Fewer adverse effects
▪Less respiratory depression
▪Lower potential for dependence
–Used to treat moderate pain
Buprenorphine (Buprenex, Butrans, Suboxone)
–Partial agonist at ____ receptors
–Antagonist at _____ receptors
–Parenteral route
▪Relief of moderate to severe pain
–Sublingual route
▪Management of opioid withdrawal & dependence
–Schedule III drug
–Partial agonist at mu (μ) receptors
–Antagonist at kappa receptors
Butorphanol (Stadol)
–Agonist at ? receptors
–Weak antagonist at ? receptors
–IV or IM route
▪Moderate to severe pain
▪Preanesthesia or general anesthesia adjunct
–Nasal spray
–Schedule III drug
–Agonist at kappa receptors
–Weak antagonist at mu receptors
Nalbuphine (Nubain)
–Agonist at ? receptors
–Weak antagonist at ? receptors
–IV, IM, subcutaneous routes
▪Moderate to severe pain
▪Preanesthesia or anesthesia adjunct
–Not a scheduled drug
–Agonist at kappa receptors
–Weak antagonist at mu receptors
Pentazocine (Talwin)
–Agonist at ? receptors
–Weak antagonist at ? receptors
–PO and parenteral routes
▪Moderate to severe pain
–Agonist at kappa receptors
–Weak antagonist at mu receptors
NSAIDs (Aspirin, ibuprofen)
– Preferred medications ^^
– Have antipyretic and anti-inflammatory properties
– Act at ______________, inhibiting pain mediators at _______________ level
– Preferred medications
– Have antipyretic and anti-inflammatory properties
– Act at peripheral sites, inhibiting pain mediators at nociceptor level
NSAIDs (Aspirin, ibuprofen) do not produce severe adverse effects of narcotics
▪No physical or psychological dependence
▪Most prominent effects:
–GI related
* Ulceration of mucosa
–Dizziness, headache, and rash
Miscellaneous analgesics such as
▪Clonidine (Catapres, Duraclon)
▪Ziconotide (Prialt)
–Tramadol (Ultram, others)
▪More widely prescribed
–Act on : ?
CNS
Tramadol (Ultram, others)
–Therapeutic classification
–Pharmacologic classification
–Therapeutic classification
▪Analgesic
–Pharmacologic classification
▪Mixed opioid-nonopioid analgesic
Tramadol (Ultram, others)
–Therapeutic effects and uses:
▪___________ pain
▪Off-label uses
–Neuropathic pain
–______________ ________ syndrome
▪Moderate pain
▪Off-label uses
–Neuropathic pain
–Restless leg syndrome
Tramadol (Ultram, others)
–Mechanism of action
▪Drug and one of metabolites bind to _______________ site
–Weak opioid agonist activity
▪Inhibits_________________________________________ reuptake in spinal neurons
–Inhibits transmission of pain impulses
▪Drug and one of metabolites bind to mu receptor site
–Weak opioid agonist activity
▪Inhibits norepinephrine and serotonin reuptake in spinal neurons
–Inhibits transmission of pain impulses
Tramadol (Ultram, others)
–Adverse effects
▪Vertigo / Dizziness
▪Headache
▪Nausea / Vomiting
▪Constipation
▪Lethargy
▪CNS stimulation effects
▪Seizures
▪Respiratory depression
▪Possible physical dependence
Tramadol (Ultram, others)
– Contraindications/precautions
▪Hypersensitivity
▪History of depression or suicidal ideation
▪Pregnancy
▪Precautions
–Codeine allergies
–History of drug abuse
–Chronic Obstructive Pulmonary Disease (COPD)
–Renal/hepatic impairment
–Increased ICP
–History of seizures
–Contraindicated in children younger than age 12
Tramadol (Ultram, others)
–Drug interactions
▪Increased risk of seizures
–Carbamazepine, certain antidepressants
–MAOIs
▪Sudden death if combined with ethanol
▪Reduced analgesic effect
–Inhibitors of CYP2D6 enzyme
▪Herbal/food
–Food significantly affects absorption of
extended release form
–St. John’s wort contraindicated; possibility of
serotonin syndrome
–Caution with valerian or kava; additive CNS
depressant effect
Tramadol (Ultram, others) –Treatment of overdose
▪Serious CNS depression, respiratory depression, death possible
▪Naloxone
–May precipitate convulsions
Adjuvant analgesics
–Diverse group of drugs used to : ?
enhance analgesia for specific indications
- Adjuvant analgesics
Primary indications
▪Pain refractory to opioids (such as intractable cancer pain)
▪Neuropathic pain
Preferred drugs for abusers:
Morphine, meperidine, and heroin
- OxyContin
–Major drug of abuse in recent years
–Long-acting form of oxycodone
▪Beneficial to patients with chronic pain
▪Can be crushed, injected, snorted
–Potent and dangerous
Acute opioid intoxication - Respiratory depression
▪Treat with : ?
▪Repeat small doses until patient exhibits opioid withdrawal symptoms
–Maintain patent ____________
–Have resuscitation equipment available
▪Treat with naloxone (Narcan)
▪Repeat small doses until patient exhibits opioid withdrawal symptoms
–Maintain patent airway
–Have resuscitation equipment available
- Evzio
–Handheld autoinjector containing naloxone to treat individual with :
known or suspected opioid overdose
–Tension headache
▪Muscles of head & neck tight due to :
▪Treat with :
▪Muscles of head & neck tight due to stress
▪Self-limiting
▪Treat with OTC analgesics
Migraine headache
▪Throbbing, pulsating pain
▪Preceded by aura
–Sensory warning of imminent attack
▪Patients appear to have___________________ that overreact to various triggers.
▪Neurotransmitter _______________ plays key factor.
▪Throbbing, pulsating pain
▪Preceded by aura
–Sensory warning of imminent attack
▪Patients appear to have blood vessels that overreact to various triggers.
▪Neurotransmitter serotonin plays key factor.
About ____ of patients with migraines have a first degree relative with a history of migraine.
70%
Before puberty, more boys have migraines than girls;
after puberty, women are _______ more likely to have migraines than men.
3 times
History of migraine is associated with an increased incidence of __________________________________, especially if the patient experiences migraines with aura.
major cardiovascular disease
- Migraines are rare after age:
50
Mild migraine (occasional headaches with no other functional impairment) treatment
–NSAIDs
–Acetaminophen combined with NSAID and caffeine
–Oral serotonin 5-HT agonists
▪Triptans/ergot alkaloids
