8 - Pain 1 Flashcards
1
Q
What is pain?
A
Unpleasant sensory and emotional experience associated w/ actual or potential tissue damage
2
Q
What causes nociceptive pain?
A
Activation of pain pathways by ongoing tissue damage
3
Q
What are the subcategories of nociceptive pain?
A
- Somatic
- Visceral
4
Q
What is somatic pain?
A
- Pain arising in tissues of the body
- Sharp, sometimes burning, aching
5
Q
What are examples of somatic pain?
A
- Osteomyelitis
- Osteoarthritis
- Bone fracture
6
Q
What is visceral pain?
A
- Pain arising in organs of a body cavity
- Deep, aching, cramping, poorly localized
7
Q
What are examples of visceral pain?
A
- Endometriosis (pelvis)
- Crohn’s disease (abdomen)
- Angina (thorax)
8
Q
Can visceral pain be managed w/ OTC products?
A
No, so require referral
9
Q
What causes neuropathic pain?
A
- Direct nerve damage
- Abnormal processing of a pain signal in CNS pain pathways
10
Q
What is neuropathic pain generally described as?
A
Burning, tingling, shock-like, or shooting pain
11
Q
What are some examples of neuropathic pain?
A
- Diabetic neuropathy
- Post-herpetic neuralgia
- MS
- Phantom limb pain
12
Q
What is hyperalgesia?
A
When a stimulus that would normally cause discomfort causes significant pain
13
Q
What is allodynia?
A
Pain due to stimulus that doesn’t normally evoke pain
14
Q
What is phantom pain?
A
Pain in a limb that is no longer there
15
Q
What is the difference between acute, sub-acute, and chronic pain?
A
- Acute lasts 2-4 weeks
- Sub-acute lasts 4-12 weeks
- Chronic lasts longer than 12 weeks
16
Q
What is break-through pain?
A
- A temporary increase in pain greater than moderate intensity that occurs on a baseline pain of moderate intensity or less
- Ex: px after surgery that is on an analgesic has a dressing change
17
Q
What is incident pain?
A
Type of breakthrough pain that is made worse by movement
18
Q
What tools can be used to assess pain?
A
- Numerical rating scale (appropriate for adults)
- Visual analogue scale (horizontal line w/ left side meaning no pain and right side meaning worst pain)
- Wong-Baker FACES pain rating scale (appropriate for children and px that don’t speak english)
19
Q
What is the most accurate evidence of pain/intensity?
A
Px description and self-reporting
20
Q
What are the 4 main pieces essential to pain information gathering?
A
- Severity of pain
- Location of pain
- Onset and how long pain lasts
- Quality of pain (description– dull ache, sharp pain, tingling or burning)
21
Q
What is OTC pain medication effective at treating?
A
- Mild to moderate somatic pain from skin, muscles, and joints
- Dysmenorrhea
- Headache
22
Q
Are OTC pain meds effective in tx neuropathic pain?
A
For some px
23
Q
What are the types of OTC pain meds?
A
- NSAIDs (ibuprofen, ASA, naproxen)
- Non-anti-inflammatory analgesics (acetaminophen)
- Opioids (codeine 8 mg)
- Other (caffeine, muscle relaxants, topical counter-irritants)
24
Q
How does acetaminophen prevent pain?
A
- Central inhibition of prostaglandins
- Peripherally blocks generation of pain impulses
25
What is acetaminophen a first line therapy for?
- Mild to moderate pain (low back pain, osteoarthritis, some headaches)
- Fever
26
What is the duration of acetaminophen?
4-6 hours
27
When does acetaminophen produce a ceiling effect?
Over 1000 mg
28
What can contribute to acetaminophen toxicity?
- Overdose
| - Disease and lifestyle issues (hepatitis, cirrhosis, chronic alcohol use, binge drinking)
29
What is the minimum toxic single dose of acetaminophen in a healthy adult and in children?
- 7.5-10 g in adults
- 150 or more mg/kg in children
- Over an 8 hour period
30
What are the sx of acetaminophen overdose?
- Early sx = N/V, drowsiness, confusion, sweating
- Biochemical evidence of liver damage after 24-48 hours
- Hepatic damage may not be apparent for 4-6 days
31
Why can alcoholism lower the threshold for acetaminophen liver damage?
- Possible induction of enzymes
- Hepatic dysfunction
- Decreased stores of glutathione
32
Severe liver damage may occur in adults who drink ___ alcoholic drinks/day while taking acetaminophen
3 or more
33
What are the pharmacological properties of NSAIDs?
- Analgesic
- Anti-platelet
- Anti-pyretic
- Anti-inflammatory
34
Is ASA a first line analgesic?
No
35
What is the mechanism of ASA?
Works primarily in periphery (anti-inflammatory)
36
What is the same and different btwn acetaminophen and ASA?
- Equally effective
| - ASA has higher side effects (gastric irritation, nausea)
37
What is the dosing of ASA?
- 325-650 mg q4-6h
| - Max 4g/ 24 h
38
What are some adverse effects of ASA?
- Abdominal pain w/ cramps
- Heartburn
- Dyspepsia
- GI irritation
39
What are the contraindications for ASA?
- Under 18 y/o
- Active GI lesions
- History of recurrent GI lesions
- Bleeding disorders
- Hypersensitivity
- Px relying on vasodilatory renal prostaglandins for renal function
40
What types of pain is ibuprofen indicated for?
- Minor pain
- Headache
- Common cold
- Toothache
- Fever
- Dysmenorrhea
41
How long does the analgesic effect of ibuprofen last?
6-8 hours
42
Can ibuprofen be given to a px w/ an ASA allergy?
No
43
Can naproxen be given to a px w/ an ASA allergy?
No
44
Mucosal damage through NSAID use is primarily a consequence of _____
COX-1 inhibition
45
Which px are at high risk of GI intolerability of NSAIDs?
- Peptic ulcer disease
- GI bleeds or perforation
- Concomitant alcohol
46
NSAIDs should always be taken w/ ____
Food
47
How can ASA cause damage to GI mucosa?
- Local irritant effect from drug contacting gastric mucosa
| - Systemic effect from prostaglandin inhibition
48
What are some risk factors for upper GI bleeding?
- 60 y/o or older
- Concomitant use of alcohol
- Concomitant use of other NSAIDs, anticoagulants, antiplatelets, bisphosphonates, SSRIs, or systemic corticosteroids
- History of uncomplicated or bleeding peptic ulcer
- Rheumatoid arthritis
49
What affects do enteric coated forms of ASA have on the GI?
- Reduce risk of mucosal lesions and local irritation
| - Don't reduce risk of major GI bleeding
50
What are signs of GI bleeding?
- Black, tarry stool
- Blood in vomit
- Blood in stool
51
What are prostaglandins important for?
Maintenance of renal blood flow and tubular transport of electrolytes
52
When does prostaglandin release increase?
In response to increased levels of angiotensin 2 and norepinephrine
53
What is an important drug-drug interaction w/ NSAIDs?
Anti-hypertensive agents (ACE inhibitors, diuretics, beta blockers)
54
Which px are at risk of renal failure when using NSAIDs?
- Volume depletion states (dehydrated)
- Severe congestive heart failure
- Hepatic cirrhosis
- Creatinine clearance less than 30 mL/min
55
What is ASA-induced asthma?
Onset of asthma 30 mins to 3 hours post ingestion of ASA
56
Which px is ASA-induced asthma common in?
Asthmatics w/ concomitant allergic rhinitis or nasal polyps
57
What is the proposed mechanism for ASA-induced asthma?
Decreased prostaglandins causes increased leukotrienes
58
Can acetaminophen be given to px w/ ASA allergy?
Yes, but no more than 1g/day
59
What is white willow bark?
Natural health product similar to ASA
60
Can a COX-2 selective inhibitor (ex: celebrex) be used in px w/ ASA allergy?
Doesn't affect levels of prostaglandins, so shouldn't be a problem, but monitor closely
61
Which NSAIDs inhibit platelet aggregation?
ASA and ibuprofen
62
How long before surgery should ASA be discontinued? Why?
1 week to decrease risk of bleeding during and after surgery
63
How long before surgery should naproxen and ibuprofen be discontinued?
- Ibuprofen = 24 h
| - Naproxen and other NSAIDs besides ASA = 3 days to err on side of caution
64
What is an important drug-drug interaction w/in the NSAID class?
- Regular use of ibuprofen 400 mg may interfere w/ cardioprotective effect of low dose ASA when taken at the same time
- Ibuprofen also has effect on naproxen
65
What should be done if ibuprofen must be taken w/ low dose ASA?
Take ibuprofen at least 2 hours after ASA/naproxen
66
What can happen if warfarin and ASA are taken together?
Increased INR and bleeding risk
67
What can happen if warfarin and ibuprofen/naproxen are taken together?
- No effect on INR
| - GI irritation, so increased risk of bleeding
68
When is acetaminophen considered a first line therapy?
- ASA-sensitive asthma
- Gastritis or PUD
- Increased risk of bleeding
- Px w/ renal dysfunction
- CV or hypertensive px
- Multiple concurrent drug therapy
- Pregnant or breastfeeding (esp. 3rd trimester)
69
What is the active analgesic metabolite of codeine?
Morphine
70
How is codeine use preferred?
Short term, as adjunctive therapy
71
When should a px be referred who is taking codeine?
If no benefit for moderate pain in 2-3 days
72
What effect does caffeine have as an analgesic?
Enhances analgesic effects of ASA and acetaminophen
73
What is the recommended tx for pain that is 1-4 (mild to moderate)?
- Acetaminophen, ASA, ibuprofen, or naproxen at OTC doses
| - Monitor according to type of pain and agent selected
74
What is the recommended tx for pain that is 4-8 (moderate to severe)?
- Consider addition of codeine combination or alternative (2-3 days)
- May need to switch to T3 or tramadol (weak opioids)
75
What is the recommended tx for pain that is 8-10 (severe)?
- Refer depending on acute/chronic situation, px history, and red flags
- Likely requires stronger opioids
76
What are some general red flags for pain?
- Escalating
- Unresponsive to appropriate therapy
- Severe
- Px is pregnant
- Px uses concurrent therapies or has other illnesses
77
Why shouldn't medications be mixed in a bottle of milk or formula?
If child doesn't finish the entire bottle then you don't how much medication they received
78
What is thought to occur after a migraine is triggered?
- Dilation of intracranial and extracerebral blood vessels
- Activation of trigeminal sensory nerves
- Leads to pain signals in brain
79
An aura is thought to be due to ____
Neuronal dysfunction
80
How long do auras typically last? How long after an aura will a migraine occur?
- Typically last less than 1 hour
| - Migraines occur w/in 60 mins of aura ending
81
What is the potential pathophys of tension headaches?
Thought to occur due to mental stress and tension
82
What is the location for a tension headache, migraine headache, and cluster headache?
- Tension = bilateral
- Migraine = mainly unilateral, can spread to bilateral
- Cluster = only unilateral
83
What is considered a chronic tension headache?
Headaches on 15 or more days per month
84
Which products most often cause medication-overuse headaches?
- Caffeine and/or opioids
| - Acetaminophen or ASA
85
What are the sx of medication-overuse headaches?
Mimic tension headaches
86
What is the tx for medication-overuse headaches?
- Discontinue implicated drugs
- Relieve withdrawal sx
- Tx recurrent headaches w/ appropriate Rx migraine therapies (so would refer)
87
What are red flags for headaches?
- Severe or abrupt onset
- Age of onset over 40 y/o
- Recent head trauma
- Medication-overuse
- Progressive severity and/or increased frequency
- Neurological signs or symptoms (stiff neck, fever, reduced consciousness)
- Systemic sx
- Nocturnal occurrence
- Onset w/ exercise or exertion
- Chronic tension headaches
88
What are some non-pharms for migraine headaches?
- Cryotherapy
- Relaxation techniques (quiet, dark room, sleep)
- Massage, acupuncture
- Stress management
- Exercise (helps some, worsens others)
- Avoid triggers
89
When are OTCs used for migraines headaches?
Px w/ mild to moderate migraine pain
90
When is Rx therapy required for migraine headaches?
- OTC doesn't work
| - Tx being used more than 15 days per month
91
What are the Rx options for migraines?
- Acute tx w/ triptans (sumatriptan, zolmitriptan)
| - Prevention (propranolol, amitriptyline)
92
What should be monitored w/ headaches?
- Relief of pain w/in 2 hours after taking medication
| - If additional sx present, relief of those sx should also occur in that time
