Lecture Pain Flashcards
Immediate goal of pain management
to reduce pain to a level that allows patient to perform reasonable ADLs.
Patient should be considered expert of his or her own pain.
Pain management is a patient right.
Try to get patient in steady state of pain relief rather than react to pain
Dosing should be individualized and adjusted.
i) Adverse effects should be anticipated and prevented whenever possible.
ii) Around-the-clock dosing should be implemented for moderate/severe pain.
iii) Easier to maintain pain-free level than eliminate existing, escalating pain
Analgesia
Loss of sensibility to pain
Anesthesia
Loss of pain and loss of all other sensation
Acute pain
pain with abrupt onset but brief duration; <6 months
Chronic pain
pain lasting longer than 6 months
Maximum daily dose of acetaminophen
4000mg
opioid agonists
(1) Activate mu and kappa receptors
(2) Relieve moderate to severe pain
(3) large effect with large dose
Morphine, fentanyl, meperidine, methadone, hydromorphone, codeine, oxycodone, hydrocodone
mixed opioid agonist-antagonist
(1) Work on one receptor but block or have no effect on another
(2) Treat moderate pain with less risk
(3) less risk, less side effects, moderate pain treatment
pantazoin, nalvuphine, butophanol
opioid antagonist
(1) Block mu and kappa receptors
(2) Treat opioid overdose
(3) Naloxone
adverse effects of opioids:
GI effects
(1) Nausea, vomiting
(2) Constipation
CNS depression
(1) Sedation
(2) Euphoria
(3) Intense relaxation
Other
(1) Pruritus
(2) Respiratory depression
(3) Orthostatic hypotension
(4) Increased intracranial pressure (ICP)
(5) Risk of physical and psychological dependence
(6) Dizziness, hallucinations, anxiety
(7) Tolerance
(8) Urinary Retention
Morphine AE:
Respiratory depression
(a) (min) IV 7, IM 30, SQ 90
(b) Infants and elderly esp susceptible to resp depression
Constipation
(a) impaction, bowel perforation, rectal tear, hemorrhoids
(b) interventions include: increase physical activity, increase fluids and fiber, stool softener, stimulant laxative
Orthostatic hypotension (a) sit/lay down – rise slowly
Urinary retention & urgency
Cough suppression
(a) Can cause ↑ accumulation of secretions so have pt cough and deep breathe
N/V, Euphoria, Miosis, Sedation, Tolerance, Physical dependence
Abstinence syndrome from abrupt stop of Morphine
~10 hours
Initially: Yawning, rhinorrhea, sweating
Later: Violent sneezing, weakness, N/V/D, abdominal cramps, bone/muscle pain, muscle spams, kicking movements
7 – 10 days if untreated
Won’t die from detox, but will be painful
Morphine toxicity
Classic triad - coma, respiratory depression, pinpoint pupils
Interventions
(a) Ventilator support
(b) naloxone [Narcan]
fentanyl
100 x more potent than morphine
Via 3 routes
Parenteral - surgical anesthesia
Transdermal - patch (heat acceleration), iontophoretic; uses electricity to deliver (almost like a needle)
Transmucosal - lozenge, buccal film/tablet, sublingual tab/spray
meperidine [Demerol]
Naloxone [Narcan] does NOT reverse meperidine!!
short ½ life, toxic metabolite accumulation
hydromorphone
Often used as PCA
Less nausea but more othostatic hypotension than morphine
More rapid onset, but shorter duration of activity than morphine
codeine
moderate to strong opioid agonist used for pain & cough suppression
usually oral (alone or with aspirin or acetaminophen)
30 mg = 325 mg acetaminophen
oxycodone
analgesia about the same as codeine
immediate vs extended release (ER) -> breakthrough vs chronic pain
OxyContin – abuse – crush & snort/inject
BUT new formulation (2010) harder to crush & doesn’t dissolve into injectable solution
hydrocodone
most widely prescribed drug in U.S.
combined with ASA, acetaminophen [Lortab], ibuprofen [Vicodin]
in these combos watch for max acetaminophen dose (4000mg/day) - can go over if take tylenol in addition to meds
Naltrexone
used for opioid and alcohol abuse
NSAIDs
Three major classes of NSAIDs
i) Salicylates
ii) Ibuprofen and ibuprofen-like agents
iii) Cyclooxygenase-2 (COX-2) inhibitors
Aspirin & ibuprofen are the Drugs of choice
Indications
(1) Have antipyretic and anti-inflammatory properties
(2) Act at peripheral sites, inhibiting pain mediators at nociceptor level
AEs
(1) Do not produce severe adverse effects of narcotics
(2) No physical, psychological dependence
(3) Most prominent effects are GI related, Ulceration of mucosa
tramadol [Ultram]
Moderate pain
bind to mu receptor (so considered a mild opioid)
Inhibits transmission of pain impulses
A/E:
(1) Seizures
(2) Respiratory depression
Overdose: naloxone
clonidine [Duraclon]
intrathecal (injected into spinal cord)
adjunct for cancer pain
AEs: severe hypotension, rebound HTN, bradycardia
aspirin [Acetylsalicylic Acid]
first generation salicylate
Indications
i) Analgesic
ii) Anti-inflammatory
iii) Antipyretic
iv) Suppress platelet aggregation
COX 1 & 2 inhibitor
Has adverse effects on GI mucosa:(1) Stomach irritation/pain, Heartburn, N/V, Diarrhea, GI bleeding
also Tinnitus and Reye’s syndrome
Ibuprofen Like Drugs
the most common drugs for treating mild to moderate pain and inflammation.
Indications:
i) analgesic,
ii) anti-inflammatory, and
iii) antipyretic
All inhibit COX 1 and 2
AE:
i) Can damage GI mucosa – risk for GI bleeding!
ii) Many are nephrotoxic at high doses.
Ibuprofen, Ketorolac, Naproxen
Ibuprofen interactions
(1) Oral anticoagulants can increase risk of bleeding
(2) Other NSAIDs, alcohol, or corticosteroids may cause serious adverse GI events
Ibuprofen OD treatment
(1) Administration of activated charcoal and nasogastric suction
COX 2 inhibitors
Second-generation anti-inflammatory
Block COX-2 but not COX-1
Less GI bleeding and ulcer formation than with ibuprofen or aspirin
Limited use due to risk of MI and stroke (Increased risk)
celecoxib [Celebrex]
celecoxib [Celebrex]
COX 2 inhibiotr
anti-inflammatory
AE:
(1) Dyspepsia, abdominal pain,
(2) sulfonamide allergy
(3) Serious adverse effects
(a) MI that can be fatal
(b) Stroke
(c) HTN, Peripheral edema, Renal and hepatic impairment
Interactions: Reduced antihypertensive action of diuretics or ACE inhibitors
OD: same as ibuprofen (activated charcoal and nasogastric suction)
acetaminophen
aka APAP, Paracetamol, ofirmev
Indications:
i) Analgesic,
ii) antipyretic
iii) **NOT anti-inflammatory (or antirheumatic action)
Not an NSAID
iii) Does not cause GI bleeding or ulcers
iv) Often combined with opioid analgesics
(1) Acetaminophen and ibuprofen together = hydrocodone!!
acetaminophen and alcoholics
Assess alcohol use – if 3+EtOH, <2000 mg / day
acetaminophen OD
Treatment: acetylsteine (Mucomyst, Acetadote)
usually occurs w/in 8-10 hours of ingestion
