Pain II Flashcards
Common Musculoskeletal Injuries and Disorders
- Myalgia (muscle)
- Tendonitis
- Bursitis (fluid sac)
- Sprain (ligament)
- Strain (muscle or tendon)
- Osteoarthritis
Common Duration of Injuries
- Acute (sports) injuries: < 4 weeks, pain, bruising, swelling, temporary loss of function, gradual stiffening
- Chronic overuse of body part: > 4 weeks, functional impairment, nerve involvement, progression of symptoms
Treatment Goals
- Decreasing the subjective intensity and duration of pain
- Restoring function
- Preventing re-injury
- Preventing acute pain from becoming chronic pain
Exclusion for Self-Treatment
- Moderate to severe pain (pain score >6/10)
- Pain that continues > 10 days (with or without treatment)
- With treatment if pain continues >7 days
- Increased intensity or change in character of pain
- Pelvic or abdominal pain (other than dysmenorrhea)
- Accompanying nausea, vomiting, fever, or other signs of systemic infection or disorder
- Visually deformed joint, abnormal movement, weakness in any limb, or suspected fracture
- 3rd trimester of pregnancy
- <2 years of age (and <18)
- Back pain and loss of bowel and/or bladder control
Non-drug Treatment of Acute Injury
- Rest: rest the injured area until pain is reduced (generally 1-2 days), slings, splints, or crutches can be used if necessary
- Ice: apply ice ASAP to injured area in 15 min increments 3-4 times a day for 1-3 days
- Compression: choose appropriate size of bandage for injured area, decrease tightness of bandage as you continue to wrap
- Elevation: elevate the injured area at or above the level of the heart 2- 3 hours a day to decrease swelling and to relieve pain
Topical Products
- Recommended in addition (adjuvant) to either systemic analgesic OR non- pharmacological therapy of musculoskeletal injuries and disorders.
- Topical analgesics may have local:
- Analgesic
- Anesthetics
- Antipruritic
- And/or counterirritant effects
Counterirritants
- Counterirritants= “the temporary relief of minor aches and sprains of muscles and joints”
- Relieve pain from nerve stimulation rather than depression
- Paradoxical pain-relieving effect achieved by producing a less severe pain to counter a more intense one
- Psychological component: pleasant odor, sensation of warmth or coolness
- Other factors that affect response: choice of irritant, concentration, solvent used, duration of contact on skin
Methyl Salicylate: Group A
Occurs naturally as winter green oil, sweet birch oil, gaultheria oil and teaberry oil, “mountain tea”
Responsible for the “hot” action in many combination topical counterirritants due to rubefacient action.
Also inhibition of prostaglandin in the local area
Systemic bioavailability increases with
-Occlusive dressing
-Multiple application
-Plantar > heel > instep (arch) > forearm > abdomen
Systemic reaction/precaution: Salicylate toxicity, Salicylate allergy, nasal polyp, severe asthma, Warfarin DDI (and other aspirin/NSAID related drug interactions)
Camphor: Group B
Naturally occurring form camphor tree, but most of camphor is prepared synthetically
[0.1-3.0%]: depressed cutaneous receptors for topical analgesic, anesthetic, and antipruritic.
>[3.0%]: stimulates nerve endings for counterirritant effects
When applied vigorously it produces rubefacient reaction
Ingestion - 10 minutes - seizures (911)
Placing camphor into the nostrils may cause immediate respiratory collapse
Only <11% on the market currently
Menthol: Group B
Either prepared synthetically or extracted from peppermint oil.
Can be used in small quantities as a flavoring agents: candy, gum, etc.
Can be used for upper respiratory congestion and rhinitis (in cough drops and vapo-rubs)
Also provides relief for dyspnea
Permeability enhancer: ↑ absorption of other topical medications
<1% acts as anesthetic
>1.25% acts as counterirritant
Methyl Nicotinate: Group C
Vasodilation and elevation of skin temperature
This is partly mediated via prostaglandin biosynthesis
- Ibuprofen, aspirin, indomethacin depress the skin’s vascular response to methyl nicotinate
Toxicity (applying over large area): ↓BP, ↓ HR, syncope
Capsaicin: Group D
Additional indications compared to other groups
-↓ pain (not inflammation) in rheumatoid and osteoarthritis
-Post-herpetic neuralgia (shingles)
-Psoriasis
-Diabetic neuropathy
Overdose: none reported
>1% concentration has been associated with neurotoxicity and hyperalgesia
Use a glove or plastic bag for application and wash hands following use
OTC Combination Products
Counsel patients to:
- Use only the provided combinations by manufacturers
- Do not combine on your own
- It does not make sense to combine counterirritants with local anesthetics/topical analgesics. They oppose the affects of each other!
Product Selection
Topical analgesics or counter irritants should not be use in children <2 year-old
In children 2-18, use products with caution for the least amount of time
Ointments and oil-based liniments have increased absorption compared with solutions, gels, lotions, and creams, but they are greasy and generally less acceptable
Topical patches
-The use of patch is becoming popular due to simple application and duration of action
-But the use of patch eliminates the benefit and therapeutics of rubbing action
Patient Education: Counterirritants
-Do not use if skin is abraded, sunburned, or
otherwise damaged
-Wash hands before and after application
-Gently rub a thin layer
-Do not use a tight bandage or dressing over a treated area
-Do not use warming devices over treated area
-Take caution when applying during excessive exercise
-Stop using if: asthma/wheezing etc worsen, excessive redness/blistering/hives, if > 7 days see PCP
