Pain lecture

• 1. Mild
• Aspirin
• Acetaminophen
• NSAIDs
• +/- adjuvants

• 2. Moderate
• APAP/Codeine
• APAP/Hydrocodone
• APAP/Oxycodone
• APAP/Dihydrocodeine
• Tramadol
• +/- Adjuvants

• 3. Severe
• Morphine
• Hydromorphone
• Methadone
• Levorphanol
• Fentanyl
• Oxycodone
• +/- Adjuvants

• Differ from opioids:
• Ceiling effect applies
• No tolerance or physical dependence
• Not associated with abuse/addiction
• Antipyretic
• Most=Anti-inflammatory

APS recommends consideration for all analgesic regimens unless high risk or ineffective.

(N-Acetyl-Para-Amino-Phenol or APAP)

MOA: ?, central

• Use:
• · Analgesic and anti-pyretic
• · No anti-inflammatory effect
• · No anti-platelet activity
• · No GI damage

• Useful for mild-moderate pain
• · Use alone or in combination
• · Dose limit = 4000 mg/day, divided doses (ALF rec.3000 mg)

• Safety
• · Use with caution in pts with liver dz or alcoholism
• · FDA – hot topic - associated with liver damage, often combined with other meds and pt is unaware

• Drug interactions
• · MinimalWarfarin

• Aspirin (Bayer, Ecotrin, Norwich)
• Choline magnesium trisalicylate (Trilisate)
• Diflunisal (Dolobid)
• Magnesium salicylate (Doan’s)
• Salsalate (Disalcid)

Acetylsalicylic acid or ASA

MOA: inhibits Cox-1/Cox-2

• Use
• Mild to moderate pain
• Antipyretic, anti-inflammatory
• Low-dose: cardioprotection (only irrev. inhibition of platelet aggregation)

• Safety
• Upper GI disturbance and bleeding
• Increased bleeding time
• Hypersensitivity/bronchospasm in asthma pts (nasal polyps)
• Tinnitus with high doses
• Blood pressure (BP) increases
• Avoid in children <12 with viral illness (Reyes syndrome)
• Risk of hypersensitivity reaction (and cross-sensitivity with NSAIDs)
• Many drug interactions

• MOA:
• inhibit Cox-1/Cox-2
• Ex: ibuprofen (Motrin, Advil, Caldolor), naproxen (Naprosyn), diclofenac (Voltaren, Flector patch, Pennsaid), indomethacin (Indocin)

• Use
• Mild to moderate pain
• Antipyretic, anti-inflammatory

• Safety
• GI erosion / risk of bleeding (less than aspirin)
• Decreased renal perfusion
• Rashes, hypersensitivity/bronchospasm in asthma pts
• Blood dyscrasias, liver effects, CNS effects, BP
• Drug interactions
• Bind to plasma proteins – many drug interactions

Celecoxib (Celebrex)

• Use
• Mild to moderate pain for patients at risk for GI ulcers

• Safety
• Increased risk of cardiovascular toxicity (Black Box)
• Lower GI toxicity than NSAIDs
• Relative risk 2.6 vs. 3.7
• Use of ASA with Cox-2 eliminates advantage
• Sulfonamide allergy
• Renal
• Drug interactions

Full agonist (most common)

• Antagonist (stop effects of opioids)
• Naloxone, Naltrexone

• Mixed Agonist/Antagonist
• Buprenorphine, Butorphanol, Nalbuphine, Pentazocine, Bupenorphine/Naloxone (Suboxone)

• Morphine-like
• Morphine (MS Contin, Kadian, avinza)
• Hydromorphone (Dilaudid)
• Codeine (prodrug for morphine)
• Hydrocodone
• Oxycodone (Oxycontin)

• Meperidine-like
• Meperidine (Demerol)
• Toxic metabolites with repeated dosing
• Esp. renal failure, elderly
• Not recommended for chronic pain
• Fentanyl (Duragesic)

• Methadone-like
• Methadone (Dolophine)
• Propoxyphene (Darvon)
• High adverse reaction profile
• Not recommended for elderly or for chronic pain
• Little evidence that it is any more effective for mild to moderate pain than less toxic non-opioid drugs

• Short:
• Codeine
• Hydrocodone
• Hydromorphone
• Morphine
• Oxycodone
• Tapentadol
• Fentanyl (ultra-short)

• Long:
• Methadone
• Buprenorphine
• Sustained relase products of short acting

Constipation: It is inevitable! Prevent it and treat it. Stool softeners, fluid, fiber, exercise

Nausea/vomiting: Common early in therapy, ↓ with time, Codeine

Sedation/cognitive impairment: Transitory (at initiation and dose escalation), Decrease dose?, trial of psychostimulant, rule out other causes if persistent.

• Potential serious adverse reactions:
• Respiratory depression
• Apnea
• Respiratory arrest
• Circulatory depression
• Hypotension
• Shock
• ►►naloxone (Narcan) = antagonist◄◄

• Other common reactions:
• Pruritus
• Dizziness
• Headache
• Dry mouth
• Urinary retention

• Antidepressants
• MOA: block reuptake of norepinephrine (NE) & serotonin, NMDA-receptor antagonism, sodium-channel blockade
• Tricyclic antidepressants (TCAs)
• Analgesia independent of antidepressant effect
• Ex: amitriptyline (Elavil) – more adverse reactions, nortriptyline (Pamelor), desipramine (Norpramin)
• Anticholinergic adverse reactions prominent: dry mouth, urinary retention, constipation, sedation, and orthostatic hypotension, cardiac arrhythmias
• Other Antidepressants:
• Selective Serotonin Reuptake Inhibitors (SSRIs): Fewer adverse reactions but not as effective as TCAs
• Serotonin-NE Reuptake Inhibitors: duloxetine (Cymbalta), venlafaxine (Effexor), milnacipran (Savella)

• Antiepileptic drugs (AEDs)
• Another first line drug class for neuropathic pain
• Especially lancinating
• First generation: carbamazepine (Tegretol), phenytoin (Dilantin)
• Second generation: gabapentin (Neurontin), pregabalin (Lyrica)

Local anesthetics

• Topical agents
• lidocaine 5% patch (LidoDerm), Excellent choice for localized pain, 12 hours on – 12 hours off, Few adverse reactions; don’t use with class I antiarrhythmics
• capsaicin (Zostrix, Qutenza), Chile pepper derivative, Causes burning and stinging sensation, Wash hands after applying

• Miscellaneous
• - First-Line Medications
• - gabapentin (Neurontin)
• - 5% Lidocaine patch (LidoDerm)
• - Opioid analgesics
• - tramadol (Ultram)
• - Tricyclic antidepressants (TCAs)
• - Non-Pharmacologic Techniques
• - Supplement to pharmacological measures
• o Increased pain relief
• - Other advantages
• o Improve mood
• o Reduce anxiety
• o Increase a patient’s sense of control
• § Strengthen coping abilities
• o Assist with sleep
• o Relax muscles
• - Improve quality of life
• - Psychosocial
• o Patient education and preparation
• o Psychological and behavioral techniques
• - Other physical modalities
• o Physical rehabilitation
• o Electrical stimulation
• o Acupuncture
• o Heat and cold
• o Splinting, assistive devices, etc.

• CI
• High potential for abuse; no accepted therapeutic use
• Heroin, LSD

• CII
• High potential for abuse; accepted therapeutic use
• Oxycodone, morphine, cocaine
• No refills
• Can only write for a 30 day supply

• CIII
• Potential for abuse less than CII
• Ketamine, anabolic steroids
• 5 refills
• Prescription expires in 6 months
• Can only write for a 30 day supply

• CIV
• Potential for abuse less than CIII
• Benzodiazepines, phenobarbital, most sleep meds
• 5 refills
• Prescription expires in 6 months

• CV
• Potential for abuse less than CIV
• OTC codeine products, cough medicines
• 5 refills
• Prescription expires in 6 months

• CVI
• Marijuana (in NC)

• Unscheduled
• No potential for abuse
• Anything else: HTN meds, antibiotics, etc