pain assessment
is the first step to pain management
pain
subjective experience; termed acute or chronic; can be from nociceptor or neuropathic
nociceptor pain
injury to the tissue
somatic-sharp localized
visceral-dull, throbbing, aching, generalized
neuropathic pain
direct injury to the nerve; burning, shooting, numb
pain assessment
several numerical scales and survey instruments are available; need to know: location, severity, type, duration, effect on daily life
neuropathic pain
carpal tunnel syndrome, central pain syndrome, degenerative disk disease, diabetic neuropathy, intractable cancer pain, phantom limb pain, postherpetic neuralgia, post surgcial pain, sciatica
carpal tunnel syndrome
pain due to nerve compression in the wrist, thumb, and fingers
central pain syndrome
general pain caused by damage of nerves in the CNS-that is, due to stroke or MS
degenerative disk disease
back pain due to damage of nerves entering or exiting the spinal cord
diabetic neuropathy
burning or stabbing pain in the hands and feet of patients suffering from diabetes
intractable cancer pain
pain due to progressive or metastatic spread of cancer
phantom limb pain
pain occurring in some patients after a limb is amputated
postherpetic neuralgia
pain brought on by herpes and herpes-related viruses or the outbreak of shingles
postsurgical pain
pain after a surgical procedure
sciatica
leg pain due to compression or irritation of the sciatic nerve
trigeminal neuralgia
shooting pain in the upper neck and jaw
pain transmission processes
allow several targets for pharmacologic intervention
NSAIDs at peripheral level and opioids in the CNS
two main classes of pain medications and where they work
adequate pain relief
nonpharmacologic techniques and adjuvant analgesics assist in providing ___
nonpharmacologic pain management
acupuncture, biofeedback therapy, massage, heat or cold packs, meditation, relaxation therapy, art or music therapy, imagery, chiropractic, hypnosis, therapeutic touch, transcutaneous electrical nerve stimulation (TENS), energy therapies such as reiki and
radiation therapy
shrinks solid tumors that may be pressing on nerves
surgery
reduces pain by removing part of or the entire tumor
nerve block
injection of alcohol or other neurotoxic substance into neuronal tissue irreversibly stops impulse transmission along treated nerves
nonopioid analgesics
mild to moderate pain
opioid analgesics
sever pain
opioid analgesic
medications that exert their effects by interacting with specific receptors
opioids
natural or synthetic morphinelike substances; responsible for reducing severe pain; narcotic substances-produce numbness or stuporlike symptoms; drugs of choice for moderate to severe pain that cannot be controlled with other classes of analgesics
opioids
have multiple therapeutic effects, including relief of severe pain
positive effects of opiates
severe pain relief, suppress the cough reflex, slow GI motility, sedation
negative effects of opiates
respiratory depression, sedation, nausea and vomiting
patient-controlled analgesia
delivered with infusion pump; limits set to prevent overdose; patient self-medicates by pushing button
combination medications
opioids and nonnarcotic analgesics; single tablet or capsule; work synergistically to relieve pain; dose of narcotic can be kept small; minimize negative effects
popular combination analgesics
vicodin, percocet, percodan, darvocet-N 50, empirin with codeine No. 2, tylenol with codeine
opioid antagonists
substances that prevent the effects of opioid agonists; "competitive antagonists"; compete with opioid agonists for access to the opioid receptor site; acute opioid intoxication is a medical emergency (respiratory depression); Naloxone (Narcan)
opioids with mixed agonist-antagonist activity
stimulate the opioid receptor, causing analgesia; withdrawal symptoms/adverse effects (not as intense; partial activity of receptor subtypes); Buprenorphine (newer option for treatment of opioid dependence; sublingual or transdermal)
opioid agonist
morphine
opioid analgesics
natural or synthetic; target mu receptor and kappa receptor
opioid agonist with high effectiveness; opioid agonist with moderate effectiveness; opioid with mixed agonist-antagonist effects
all opioid agonist: tolerance, physical and psychological dependen
morphine
MECHANISM OF ACTION: opioid mu and kappa receptor agonist
USES: analgesia (pain relief), preanesthetic, SOB of heart failure/pulmonary edema, MI chest pain
ADVERSE EFFECTS: dysphoria, hallucinations, nausea, constipation, itching; overdose: respiratory de
naloxone
MECHANISM OF ACTION: opioid mu and kappa receptor blocker, competitive antagonist
USES: opioid overdose (ER to OR); in combo with morphine: continuous pain control
ADVERSE EFFECTS: minimal toxicity; opioid withdrawal: loss of analgesia, increase BP, tremo
opioid dependence treatment
opioid agonist; mixed opioid agonist-antagonist
methadone
opioid agonist; PO, no euphoria; not a cure, prevents withdrawal symptoms; can be used for maintenance
buprenorphine
mixed opioid agonist-antagonist; SL or transdermal; early in therapy to prevent withdrawal symptoms
NSAIDs
the preferred nonopioid analgesics for inflammation and less severe pain
NSAIDs
aspirin and other salicylates; ibuprofen and ibuprofen-like drugs; selective COX-2 inhibitors
acetaminophen and others
centrally acting nonopioid analgesic
NSAIDs
antipyretic, anti-inflammatory, analgesic; drug of choice for mild to moderate pain associated with inflammation; act by inhibiting pain mediators at the nociceptor level
COX inhibitors
prostaglandins; formed by COX-1 and COX-2; aspirin and ibuprofen both inhibit COX-1 and COX-2
COX-2 enzyme
more specific for pain and inflammation
celecoxib
COX-2 inhibitors developed for specific pain relief
centrally acting drugs
acetaminophen and tramadol
acetaminophen
nonopioid analgesic; not classified as NSAIDs; equally effective as aspirin and ibuprofen; used to reduce fever and for pain; not an antiinflammatory
NSAIDs
MECHANISM OF ACTION: inhibit cyclooxygenase; COX-1 and COX-2 inhibition: aspirin, ibuprofen;
selective COX-2 inhibition: celecoxib (at nociceptor level)
USE: pain, fever, inflammation
ADVERSE EFFECTS: high doses/prolonged doses: hepatotoxicity
aspirin
MECHANISM OF ACTION: COX-1 and COX-2 inhibition, platelet aggregation inhibition
USE: pain, fever, inflammation, anticoagulatn, reduce risk of colon cancer
ADVERSE EFFECTS: gastric pain/bleed, hepatotoxicity, salicylism
INTERACTIONS: warfarin, heparin, NS
acetaminophen
MECHANISM OF ACTION: direct action at hypothalamus to dilate peripheral blood vessels
USES: fever, pain
ADVERSE EFFECTS: higher doses: hepatotoxicity; safe at proper dose
tramadol and ziconotide
other than acetaminophen, what are other centrally acting drugs?
migraines
throbbing, pulsating pain; sometimes precede by an aura, associated with triggers
drugs for migraine treatment
triptans and ergot alkaloids
prophylaxis migraine drugss
beta blockers, caclium channel blocker, TCA, antiseizure drugs, neuromuscular blockers
triptans
selective for the 5-HT1 receptor subtype; act by constricting certain vessels within the brain
ergot alkaloids
interact with adrenergic, dopaminergic, serotonin receptors; leads to vasoconstriction; many adverse effects
sumatriptan
MECHANISM OF ACTION: serotonin (5-HT) receptor drug; vasoconstrict cranial arteries
USES: treatment of migraines (PO, intranasal, SC)
ADVERSE EFFECTS: dizziness, drowsiness, caution with cardiac disease
INTERACTIONS: MAOIs, SSRI, ergot alkaloids, other tr