Pharmacotherapy Final Exam

acute pain

pain lasts for a minute up to 3 months (sometimes up to 6 months) and improves rapidly when underlying pathology stops

e.g. acute postoperative pain, soft tissue injury, trauma, labour, bee sting

goal -> recognize and treat pain before it becomes chronic

subacute pain

subset of acute pain, at least 6 weeks, under 3 months

similar nociceptive mechanisms

chronic pain

persistent and recurrent for 3 months or more

hyperalgesia and allodynia maybe 6 months or more

can start as acute pain, but continues beyond normal healing process or

usual course for acute disease little protective mechanism

may be nociceptive, neuropathic, mixed may result in changes to pain receptors

episodic pain

intermittent episodes of pain that occur over a long period, pain-free episodes in between

breakthrough pain

transitory flare of pain occurs in setting of controlled pain

risk factors for progression from acute to chronic pain

anxiety or depression

female gender

younger adults

Hx of poor acute pain management

Hx of poor response to common analgesics

genetic predisposition

nerve damage due to surgery or injury

SCHOLAR-E pain assessment

PQRST pain assessment

pain behaviour in children

infants may present with increased fussiness and change in eating habits

preschoolers - clingy, immobile, lose verbal/motor skills, lose sphincter control

school-age children - aggressive behaviour, shame, nightmares, withdrawal from social situation

adolescents - oppositional behaviour and depression (chronic pain)

pain in the elderly

assessments can be challenging - solicit information from caregivers and family members if poor historian (e.g. dementia)

pay attention to behavioural cues (e.g. grimacing)

more prone to adverse effects from medications

single dimension pain assessment tools

verbal rating scale

numerical rating scale

visual analog scale

faces pain scale

verbal rating scale for pain

A simple pain assessment tool where patients rate their pain on a predefined scale, typically using words such as "none," "mild," "moderate," and "severe."

numerical rating scale for pain

A subjective pain assessment tool where patients assign a number to their pain level, usually ranging from 0 (no pain) to 10 (worst pain imaginable).

visual analog scale for pain

A pain assessment tool that uses a straight line, typically 10 centimeters long, where patients mark the point that corresponds to their pain intensity, with one end representing "no pain" and the other "worst pain imaginable."

faces pain scale

A pain assessment tool that uses a series of faces with varying expressions to help patients, particularly children, indicate their pain level in a way that is easily understandable.

multidimensional pain assessment tools

brief pain inventory

McGill pain questionnaire

brief pain inventory

McGill pain questionnaire

acute pain goals of therapy

recognize the patient is experiencing pain

identify and treat that cause of pain

reduce or eliminate pain

minimize adverse effects

prevent progression to chronic pain

non-pharm management acute pain

(P)RICE (cold < 48 hours after injury)

most useful for soft tissue/musculoskeletal injury

application of heat ( > 48 hours after injury)

exercise

CAM options acute pain

acupuncture, massage, chiropractic, osteopathic manipulative therapy transcutaneous electrical nerve stimulation (TENS)

cognitive behavioural therapy

biofeedback

approach to pharmacological management for acute pain

step/ladder approach

1. mild pain -> non-opioid with or without adjuvant therapy

2. mild to moderate pain -> weak opioid or multimodal fixed-dose opioids, with or without non- opioid with or without adjuvant therapy

3. moderate to severe pain -> strong opioid, with or without non-opioid, with or without adjuvant therapy

escalate is pain persists or worsens

acetaminophen

analgesic/antipyretic

used for mild-moderate pain (4-6/10 on the NRS) as monotherapy or combined with other analgesics (additive)

no anti-inflammatory properties

*hepatic impairment - dosing changes based on degree of impairment

acetaminophen adult dosage forms

PO immediate release 325 mg, 500 mg (tabs, caps)
PO extended release 650 mg (Tylenol Arthritis)

acetaminophen pediatric dosage forms

PO 80 mg/mL, 160 mg/5 mL suspension

PO 80 mg, 160 mg chewable tabs, PO 160 mg sachet

PR 120 mg, 160 mg, 325 mg

acetaminophen adult dosing

• max 4 g/day, older adults max about 3 g/day

• 325-500 mg PO Q4-6H PRN or 1 g PO Q6H PRN

• extended release 1300 mg PO Q8H PRN

acetaminophen pediatric dosing

• weight dosing: 10-15 mg/kg PO Q4-6H PRN

• fixed dosing all available (weight dosing preferred)

• max 75 mg/kg/day or 4 g/day (maximum of 5 doses/24H

• weight dosing: 10-20 mg/kg PR Q4-6H PRN (max 75 mg/kg/day, max 5 doses/24H, children under 12 -> do not exceed 1,625 mg/day)

acetaminophen A/E

acute hepatotoxicity with acute overdose or chronic high doses

allergy - associated SJS, urticaria, angioedema

acetaminophen toxicity doses and symptoms

adults -> doses above 10 g/day or single ingestion above 250 mg/kg

pediatric -> doses above 75 mg/kg/day, above 4 g/day, single ingestion above 150 mg/kg

mild toxicity A/Es: N/V, abdominal pain, fatigue

severe toxicity A/Es: liver failure, jaundice, encephalopathy, coagulopathy

acetaminophen drug disease interactions

increased risk of toxicity with pre-existing liver injury + other risk factors (alcohol > 3 drinks/day, malnutrition, low BMI, fasting more than 1 day)

acetaminophen drug interactions

warfarin -> coagulant effect increased (limit acetaminophen to under 2 g/day if used for more than 3 days)

phenytoin, carbamazepine, alcohol -> increased hepatotoxicity

acetaminophen monitoring and follow up

• pain/function - patient monitor daily, pharmacist follow up within 1 week/periodically using pain scale

• pharmacist adjust to timing/other management strategies if current dose ineffective

• educate importance of max daily dose

• patient to monitor allergic reactions

NSAIDs for acute pain

• analgesic, anti-inflammatory, antipyretic

• used for mild-moderate pain (4-6/10 on NRS), monotherapy or combined with other analgesics (additive), more effective than acetaminophen when inflammation involved

• difference is COX sensitivity depending on medication -> use lowest effective dose for shortest period (decrease risk of A/Es)

• highly protein bound, metabolized by liver, variable half life

• excreted primarily urine, also feces

ASA adult dosing

PO 81 mg, 325 mg (tabs)

dose: 325 - 1000 mg Q4-6H PRN, max 4g/day

pediatric ASA dosing

generally not used (Reye’s Syndrome)

ibuprofen adult dosing

PO 200 mg, 400 mg (tabs, caps)

dose: 200-400 mg PO Q4-6H PRN, max 3.2 g/day (1.2 g/day for self care)

ibuprofen pediatric dosing

PO 50 mg, 100 mg (tabs)

PO 100 mg/5 mL suspension, 40 mg/mL drops

dose: 5-10 mg/kg/dose Q6-8H PRN, max 40 mg/kg/day or 1.2 g/day

naproxen adult dosing

PO 220 mg (tabs, caps)

dose: 220 mg PO Q8-12H PRN max 440 mg/day for self-care

naproxen pediatric dosing

avoid under 12 years old

NSAID A/Es

caution with NSAIDs in patients with:

• renal dysfunction, CVD, CHF, HTN, asthma, hx of PUD or GI bleed

• avoid in severe hepatic failure -> hepatorenal syndrome

• pregnancy -> limit in 1st/2nd trimesters, avoid in 3rd trimester

NSAIDs contraindications

ASA-sensitive asthma or hypersensitivity to NSAID/ASA (bronchospasm, rhinitis, urticaria), before/following cardiac surgery, uncontrolled HF, active GI ulcer/GI bleeding/CV bleeding or other bleeding disorders, severe renal impairment, SLE/hyperkalemia

NSAIDs drug interactions

NSAIDs for acute pain monitoring and follow up

NSAID + acetaminophen combo

acetaminophen 325 mg + ibuprofen 97.5 mg tab

(Combogesic) mild to moderate acute pain

for adults 18+

dose: 1-2 tab PO Q6H PRN, max 12 tab in 24H

topical NSAIDs

for acute musculoskeletal conditions, more effective for smaller joints

similar pain relief to NSAIDs, delayed onset

not recommended to use topical and oral NSAIDs at the same time

topical diclofenac

1.16%, 2.32% gel applied 3-4x/day (OTC)

skin irritation, hypersensitivity, rarely systemic effects

topical non-NSAID analgesics

methyl salicylate, menthol, camphor, capsaicin, troamine salicylate

applied 1-3x/day, limited efficacy, may be helpful during rehabilitation as cooling/heating rubs or accompaniments to massage therapy

limited evidence for arnica montana for pain relief (can reduce bruising) should not be applied to bleeds/open wounds

should not be used at same time as thermotherapy -> burns

skin reactions -> pain, swelling, blistering in products with menthol

muscle relaxants for acute pain

for pain relief when muscle spasm is component of acute injury

MOA: skeletal muscle relaxation via general CNS depression

usually given in combination with NSAID or acetaminophen

e.g. methocarbamol

A/E: dizziness, drowsiness, confusion

not recommended for acute musculoskeletal injuries due to limited effectiveness in pain relief

analgesics in pregnancy

DOC = acetaminophen

brief use of NSAIDs in 1st/2nd trimester (increased risk of ductus arteriosus after this)

analgesics in breastfeeding

NSAIDs and acetaminophen can be used safely

analgesics in older adults

DOC = acetaminophen (limit up to 3.25 g/day for chronic use)

lower doses of oral NSAIDs effective for mild-moderate pain

• increase risk of GI bleed, PUD, acute kidney injury, avoid chronic use preferentially

topical NSAIDs for MSK injury -> local pain relief, fewer systemic A/Es

muscle relaxants not well tolerated due to sedation/anticholinergic A/Es

sports-related injuries

common injuries include sprains, stress fractures, overuse injuries

30-50% of sports injuries caused by soft tissue injuries

majority of injuries among adolescents -> sports-related

• higher incidence in adolescent males

mechanisms of sports-related injuries

direct injury -> occurs at site of contact

indirect injury -> related to lack of contact and maybe environmental or functional

after initial injury -> regeneration begins 3-6 days after, peaks between days 7-14

non-pharm for sports-related injuries

RICE -> rest, ice, compression, elevation

pharmacological management for sports-related injuries

OTC oral analgesics

• acetaminophen, ASA, ibuprofen, naproxen

OTC topical NSAID

• diclofenac 1.16% or 2.32% gel applied 3-4x/day

others

• prescription NSAIDs

• oral muscle relaxants -> pain relief when muscle spasms are part of symptomology

• external analgesics -> methyl salicylate, methanol, camphor, capsaicin, etc

red flags for sports-related injuries

• eye injury resulting in blurred vision, vision loss, moderate to severe eye pain or discomfort

• nosebleed resulting in ongoing bleeding beyond 20 minutes

• ruptured eardrum resulting in headache, discharge from ear, slight bleeding or partial hearing loss

• head injury resulting in: confusion, unusual eye movements, slurred speech, nausea, loss of consciousness, tinnitus, seizures, vomiting, dizziness, amnesia, headache, drowsiness

sports-related injury patient assessment

sports-related injuries goals of therapy

relieve symptoms to support a return to normal functioning within 2 weeks

support the healing process

prevent-re-injury or worsening of the existing injury

sports-related injuries monitoring and follow-up

instruct patient to monitor pain and swelling daily

pharmacist to follow up after 7 (initial response to therapy, dose being used) and 14 days

if no improvement -> refer to medical practitioner

if pain is worse despite pharmacotherapy, refer to medical practitioner

monitor -> efficacy and safety from analgesics (depends on chosen agent)

lower back pain pathophysiology

pain of varying severity in spinal area in lower lumbosacral region and can extend to gluteal, hips, lower extremities

improvement within 6 weeks of presentation, slows after that

lower back pain classification

duration

• acute = < 4 weeks

• subacute = 4-12 weeks

• chronic = >12 weeks

categories

• nonspecific lower back pain (treatments listed)

• back pain with radiculopathy/spinal stenosis

• back pain with other specific spinal causes

considerations for lower back pain therapy

non-pharm management for lower back pain

risk factors for lower back pain

age (common 45-64 years old), tall, climbing stairs often, stress

poor general health, heavy lifting, physical disabilities, sciatica, whole-body vibration (e.g. work with jackhammer), obesity, smoking, pregnancy, high physical work demands, arthritis

lower back pain patient assessment

1. red flags

2. yellow flags

3.SCHOLAR-E/PQRST

4. PMHx (e.g. cancer, osteoporosis, uncontrolled chronic medical condition)

5. medication history (e.g. prolonged corticosteroid use)

6. allergies

7. social history (e.g. smoking, exercise, work that requires heavy lifting, truck driving)

8. complete the assessment and refer/offer appropriate management

lower back pain goals of therapy

relieve symptoms and promote rapid recovery

improve function and mobility

enhance quality of life

prevent or minimize re-injury

prevent progression to chronic pain minimize work absence

red flags for lower back pain

history or suspicion of cancer

signs of infection (especially in immunocompromised patients possible fracture (recent trauma, chronic corticosteroid use)

causa equina syndrome

chronic pain (> 3 months)

sciatic conditions

rapid weight loss

neurologic deficit

inflammatory disorders

new onset under age 20 or new onset over age 50

yellow flags for lower back pain

negative pain beliefs

• believe pain is severely debilitating

• fear of movement/activity

mental health concerns -> depression or anxiety

work-related issues -> belief they will never return to work

passive coping style -> relies solely on passive treatments and avoids active participation in care

social withdrawal

• reduced social interactions

• poor support systems

lower back pain non-Rx oral NSAIDs

ibuprofen 200-400 mg PO Q6-8H max 1.2g/day for self-care

naproxen 220 mg PO 1-2x/day, max 440mg/day for self-care

lower back back non-Rx acetaminophen

current guidelines do not support acetaminophen for lower back pain, evidence shows limited benefit

lower back pain non-Rx codeine combinations (Tylenol 1)

limited evidence supporting use in lower back pain

not recommended as a routine treatment option

lower back pain Rx options

NSAIDs

muscle relaxants

lower back pain Rx muscle relaxants

limited evidence of benefit

not recommended with NSAIDs

consider only if NSAIDs failed/contraindicated

Rx muscle relaxants preferred to OTC options, if needed use cautiously due to side effects

Rx muscle relaxants

• baclofen 5 mg TID increase gradually to max 20 mg TID

• cyclobenzaprine 5-10 mg PO TID

lower back pain monitoring

effectiveness -> pain relief, function/mobility improvement, trial each agent 2-4 weeks at optimal dose

safety -> medication-specific AEs, impact on activities of daily living, risk factors for complications

lower back pain follow-up

pharmacist to follow up on days 3, 7, 14, 28

refer to healthcare practitioner as required

lower back pain CAM

Devil’s Claw (Harpagoside 50-100 mg PO daily)

• potential interactions with drugs due to CYP2C9/3A4

Comfrey root (topical)

white willow bark* (salicin 120-240 mg PO daily)

cayenne* (topical)

* = can manage chronic

tension-type headaches classifications

primary: no identifiable underlying cause

• e.g. tension-type, migraines, cluster headaches

secondary: caused by specific underlying condition or substance

• e.g. medication-induced, HTN, infection

cranial nerve disorders: pain from specific nerve dysfunction/damage

• e.g. trigeminal neuralgia

tension-type headaches epidemiology

may be episodic or chronic (>15 days per month)

most common primary headache

slightly more prevalent in females

mean onset 25-30 years, peaks in 30's

exact pathophysiology unknown

risk factors: young age, female, poor general health status, work-related stress, sleep disturbances

infrequent episodic tension-type headaches

<1 day/month, <12 days per year

at least 10 episodes when headache occurs

frequent episodic tension-type headaches

1-14 days/month, >12 but less than 180 days/year

>3 month duration

at least 10 episodes when headache occurs

chronic tension-type headaches

>15 days/month

>3 month duration

> 180 days/year

frequent episodic tension-type headaches diagnosis

frequency, duration, other description of frequent episodic TTH + ALL of the following criteria:

duration: 30 minutes-7 days

headache characteristics (need minimum 2)

• bilateral location

• pressing and/or tightening mild-moderate intensity

• not worsened by physical activity

associated symptoms (must have BOTH)

• no N/V

• no more than ONE of: photophobia phonophobia

not attributed to another disorder

tension-type headaches differential diagnosis

red flags for tension-type headaches

sudden “thunderclap” headache - worst ever experienced

mental status changes (confusion, decreased alertness)

new onset of symptoms >50 years of age

fever with neck stiffness

systemic symptoms (fever, chills)

recent change in headache pattern

pregnancy or postpartum

immunosuppressed individuals

positional changes affect headache severity

triggered by coughing/sneezing

history of cancer

vision changes or swelling around the eyes

eye pain with autonomic symptoms (e.g. eye redness, tearing, facial flushing)

progressive worsening

recent head trauma

medication-induced or painkiller overuse

tension-type headaches assessment

signs of stroke:

• F: face drooping?

• A: arms - can you raise both?

• S: speech - slurred or jumbled?

• T: time -> to call 911

1. red flags

2. SCHOLAR-E

3.PMHx, medication Hx, allergies

4. Social Hx (e.g. sleep, stress levels, hydration, EtOH use, physical activity)

5.complete assessment and refer/offer appropriate management

tension-type headaches algorithm

tension-type headaches goals of therapy

achieve timely, consistent pain relief (within 2 hours)

minimize frequency of future episodes

prevent complications and adverse effects of drug therapy

maintain ability to perform daily activities

promote effective self-management to reduce healthcare resource utilization

tension-type headaches monitoring

effectiveness -> pain relief within 2 hours of acute treatment, frequency of headaches, impact on daily activities/function, sleep quality, stress levels

safety -> medication specific AEs, signs of medicaiton overuse headache

tension-type headaches follow-up

patient to daily self-monitor using headache diary

pharmacist to follow up after 7 days and again after 30 days

refer to healthcare practitioner as required

tension-type headaches non-pharm managment

patient education and reassurance

maintain headache diary

• track frequency/severity, identify triggers, monitor treatment response

lifestyle modifications

• sleep hygeine, regular exercise, hydration, balanced nutrition, stress management, avoiding triggers (e.g. EtOH, chocolate, strong odors)

during an attack

• rest in dark quiet room, heat/ice therapy to head, stress reduction

psychological interventions

tension-type headaches pharmacological management

start treatment ASAP treat with analgesics

• NSAIDs, acetaminophen

do not use more than 15 days/month to avoid MOH (medication overuse headache)

caffeine combination products (e.g. acetaminophen + caffeine)

• provides enhanced efficacy

• not greatly favoured due to potential for caffeine withdrawal headache

when to consider prevention therapy for tension-type headaches

patient with:

1. frequent episodic TTH or chronic TTH AND

2.any of the following:

• a.simple analgesics are ineffective

• b.analgesics are poorly tolerated

• c.analgesics are contraindicated

options include: amitriptyline, venlafaxine, mirtazapine

allow 2-3 months for full therapeutic effect

pathophysiology of viral rhinitis (common cold)

entry of virus into nasal cell through receptors -> infects nasal epithelial cells damaging tight junctions/disrupting membranes -> cell death

viral inflammation -> clinical symptoms appear due to injury of nasal mucosal linings

• increased vascular permeability, glandular secretion, vasodilation

• cholinergic stimulation -> increases mucous gland secretion and sneezing

viral shedding can continue for up to 3 weeks, even after viral replication peaks at 48 hours

symptoms of viral rhinitis

(symptoms peak in 2-4 days, resolve around day 7)

sore throat (mild, dry, sore, scratchy) - generally resolves in a few days (usually occurs first)

nasal congestion and rhinorrhea (later symptom)

• discharge is clear and watery at beginning, can become purulent

sneezing during first few days

cough (can last 2-3 weeks or longer, dry initially, can become productive)

headache

chills (first few days)

malaise (later symptom)

fever (infrequent in adults, low fever common in children)

dyspnea (shortness of breath) is uncommon

viral rhinitis patient assessment

1. red flags

2. SCHOLAR-E

• what sequence in appearance of symptoms?

• any fever or pain symptoms?

• any cough? wet or dry? how long has it lasted?

• exposure to close contacts who were ill?

• variation in symptoms throughout the day?

3. PMHx - personal or family hx of asthma, COPD, immunocompromising conditions

4. medication Hx - immunosuppressive medications

5. Social Hx - e.g. tobacco/marijuana use, environmental/occupational exposure, recent travel

6. vaccination history

7. allergies

8. complete assessment and refer appropriate management

viral rhinitis differential diagnosis (adults)

viral rhinitis differential diagnosis in children

croup

• early symptoms - mild fever, runny nose, fatigue, sore throat, cough

• hoarseness

• dyspnea

• wheezing that gets louder when breathing in

• barking cough that is seal-like (dry and unproductive)

• symptoms worse at night

• being in a warm shower with steam often helps symptoms

otitis media

• fever, particularly a few days into having a cold

• earache or child pulling or fingering ear

• irritability and/or lethargy

• pus coming out of ear

viral rhinitis CPS algorithm

viral rhinitis goals of therapy

alleviate symptoms within 2 weeks

eradicate viral infection or shorten duration of viral infection

lessen interference with activities of daily living

prevent complications of viral infection and adverse effects from medications

prevent person-to-person transmission