Management of Pain Flashcards
TYPES OF PAIN?
- Nociceptive
- Inflammatory
- Neuropathic
- Functional
What is NOCICEPTIVE PAIN?
• Nociceptive pain is pain in response to a
noxious stimulus.
• Can be either somatic or visceral.
What is INFLAMMATORY PAIN?
• When tissue damage occurs despite the
nociceptive defense system, inflammatory pain
ensues.
What is Neuropathic pain?
• Neuropathic pain results from damage to or
dysfunction of the peripheral or central nervous system, rather than stimulation of pain receptors.
What is functional pain?
• Functional pain is pain sensitivity due to an
abnormal processing or function of the central
nervous system in response to normal stimuli.
Define acute pain?
• Pain that occurs as a result of injury or surgery and is
usually self-limited, subsiding when the injury heals.
• Usually nociceptive, although it can be neuropathic.
Define chronic pain?
• Under normal conditions, acute pain subsides quickly.
However, in some instances pain persists for months to
years, leading to chronic pain.
• Chronic pain may be nociceptive, inflammatory,
neuropathic, or functional.
Differentiate chronic malignant and chronic non-malignant pain?
CHRONIC MALIGNANT PAIN
• Chronic malignant pain is associated with a
progressive disease like cancer or AIDS.
CHRONIC NON-MALIGNANT PAIN
• Pain not associated with a life-threatening disease and lasting longer than 6 months beyond the healing period.
Guidelines by the WHO for treatment of cancer pain?
• For mild pain (1–3/10), management should be
started at step 1.
• For mild to moderate pain (4–6/10), it should be
started at step 2.
• For moderate to severe pain (7–10/10), it should
be started at step 3.
Outline of how to treat mild, moderate, and severe pain?
• Mild pain is generally treated with nonopioid
analgesics.
• Mild to Moderate pain is treated with
combinations of medium-potency opioids +/-
nonopioid analgesics.
• Moderate to severe pain is treated with high
potency opioids +/- nonopioid analgesics .
• Adjuvant medications are added as needed to
manage adverse effects and/or to augment
analgesia
Which two drugs can be used for mild to moderate and added benefit?
Chronic pain?
• Acetaminophen and NSAIDs are often effective
for mild to moderate pain.
• Nonopioids do not cause physical dependence
or tolerance.
OPIOID ANALGESICS
• Agents of choice for the management of
moderate to severe acute and chronic pain.
Acetaminophen and NSAID’s role in the management of pain?
ACETAMINOPHEN
• Often selected as initial therapy for mild to
moderate pain.
• First-line for low back pain and osteoarthritis.
• Hepatotoxicity has been reported with excessive
use and overdose.
NSAIDs
• Used for the treatment of mild to moderate pain,
especially the pain of inflammation such as that
of arthritis and gout.
4 drugs for mild to moderate pain?
- NSAIDs
- Acetaminophen
- Codeine
- Tramadol
Drugs used for moderate to severe pain?
- Morphine (DOC in severe pain)
- Hydromorphone
- Oxymorphone
- Meperidine
- Fentanyl
- Levorphanol
- Methadone
- Oxycodone
- Hydrocodone
- Pentazocine (3rd line)
- Butorphanol (2nd line)
- Nalbuphine (2nd line)
- Buprenorphine (2nd line)
Describe Analgesic dosing?
• Analgesics should be given orally and by the
clock, ie at fixed intervals of time.
• The dose should be gradually increased until the
patient is comfortable.
• The next dose should be given before the effect
of the previous one has fully worn off.
• As the pain subsides, as-needed schedules
may be appropriate.
Define breakthrough pain?
Treatment for breakthrough pain?
• Transitory severe acute pain that occurs on a
background of chronic pain that is adequately
controlled by an opioid regimen.
• Rescue doses are given for relief.
• Typically, a short-acting supplemental opioid is
used.
• A typical rescue dose is 5 to 15 % of the basal
daily requirement of opioid.
Breakthrough pain formulations?
• Breakthrough pain may be targeted with a transmucosal fentanyl formulation. • Six formulations are available in the US: • Oral transmucosal lozenge • Immediate-release transmucosal tablet • Effervescent buccal tablet • Buccal soluble film • Nasal spray • Sublingual spray • Fentanyl oral transmucosal lozenge.
THE ANALGESIC CEILING EFFECT define?
• The analgesic ceiling effect of a drug refers to
the dose beyond which there is no additional
analgesic effect.
• Higher doses do not provide any additional pain
relief but may increase the likelihood of side
effects.
Analgesic ceiling effect with opiods and non-opioids?
• Nonopioids have an analgesic ceiling.
• Pure opioid agonists have no analgesic ceiling.
• When using a combination of an opioid with an
nonopioid, the analgesic ceiling of the nonopioid
should be the dose-limiting factor.
• Mixed agonist-antagonists, such as pentazocine,
butorphanol, nalbuphine, and buprenorphine, do
have a ceiling effect.
• They are poor choices for patients with severe
pain.
ROA for opiods?
- Opioids may be administered in a variety of routes:
- Oral (tablet and liquid)
- Sublingual
- Rectal
- Transdermal
- Transmucosal
- Intravenous
- Subcutaneous
- Intraspinal
ROA benefits of PCA?
• PCA allows patients to self-administer parenteral
analgesics.
• The patient depresses a button to activate the
PCA controller to deliver a preset dose of opiate
medication
• Patient-controlled IV delivery of opioids has
often been considered the gold standard for
management of acute postoperative pain.
• Opioids used in PCA devices include morphine,
hydromorphone, fentanyl, and methadone.
NOT RECOMMENDED ANALGESICS
FOR ROUTINE DOSING opiod agonist?
MEPERIDINE • Meperidine has a half-life of 3 h. • Its principal metabolite, normeperidine, has a half-life of 15-20 h. • Normeperidine produces significant adverse effects when it accumulates: • Dysphoria • Myoclonus • Seizures
Not recommended anaglesic for routine dosing mixed agonist-antagonist?
MIXED AGONIST-ANTAGONISTS
• Mixed agonist-antagonists are not recommended as routine analgesics, as their
dosing is limited by a ceiling effect.
• Additionally, pentazocine, nalbuphine and
butorphanol cause psychotomimetic adverse
effects.
• Mixed agonist-antagonists should not be used in
a patient already taking a pure agonist opioid.
• Competition for the opioid receptors may cause
a withdrawal reaction.
why do COMBINATION THERAPY?
• The combination of opioid and nonopioid
analgesics often results in analgesia superior to
that produced by either agent alone.
