Pain Treatment and Pain Management

Pain Treatment Overview

• Pain treatment is presented by Krysia Hudson, Sharon Kozachik, and Nicole Mollenkopf.

Objectives of Pain Treatment

• Describe the roles of NSAID salicylates and acetaminophen in pain management.
• Identify the maximum daily dose for aspirin, acetaminophen, and ibuprofen.
• Define salicylism and salicylate poisoning and describe treatments for salicylate poisoning.
• State the major toxicities of acetaminophen overdose.
• State the antidote for acute poisoning from acetaminophen.
• Identify factors that contribute to accidental and intentional overdose.
• Educate patients on how to decrease the risk of overdose.
• Describe the role of opioids in pain management.
• Explain how the route and dose of an opioid is affected by the first-pass effect.
• Apply knowledge of pharmacology to a patient case scenario.
• Identify sources of individual variation in drug response.
• Explain medication safety considerations for patients prescribed pain medications.
• List important points to include during patient and/or family education.
• Identify signs and symptoms of opioid overdose and appropriate treatment.
• Describe the mechanism of action of medications that treat acute opioid toxicity.
• Apply knowledge of the pharmacology of drugs used to treat drug abuse in a patient case scenario.

Vocabulary: Key Terms in Pain Management

• Enkaphalins, endorphins, dynorphins, opioid.
• Opiate, analgesic, mu, kappa.
• Delta, agonist, antagonist, partial agonist.
• Euphoria, dysphoria, tolerance, physical dependence.
• Abuse, withdrawal syndrome, addiction, salicylism.
• Serotonin syndrome, hypertensive crisis.

Understanding Pain

• Pain is an unpleasant sensory or emotional experience, associated with tissue damage or described in terms of such damage.
• Pain is subjective.
• Pain may affect sleep, thoughts, emotions, and daily activities.
• Pain is the most common symptom causing patients to seek medical care.

Pathophysiology of Pain

• Pain receptors are stimulated in response to mechanical, thermal, or chemical factors, including bradykinin, prostaglandin, leukotriene, histamine, or serotonin.
• Interpretation in the brain leads to a sensory experience.
• The three types of basic pain are nociceptive, inflammatory, and neuropathic.
• Assessment includes rating pain using a pain scale.
• Pain experience is assessed using the Pain alphabet, OLDCARTS, or COLDSPA.

Types of Pain

• Inflammatory pain examples include sunburn and abscess.
• Neuropathic pain examples include MS, neuropathy, and SCI.
• Nociceptive pain examples include cancer, disc herniation, post-op pain, trauma, and childbirth.

Pain Alphabet Explained

• "Q" stands for Quality of Pain.
• "R" stands for Region(s) Where Pain is Located.
• "S" stands for Severity of Pain.
• "T" stands for Timing of Pain.
• "U" stands for what the Pain is Usually Associated With.
• "V" stands for anything that provides Relief from Pain.
• "W" stands for anything that Worsens Pain.

Pharmacology of Pain Management

• Goals of therapy include relieving, preventing, and making pain tolerable, and quickly relieving acute pain.
• Chronic pain management involves establishing goals with the patient; total relief might not be realistic, aim is restoring functionality.

Drug Selection: WHO Analgesic Ladder

• Provides a strategy for escalating analgesic therapy.
• Step 1 involves acetaminophen or NSAIDs.
• Step 2 involves acetaminophen + opioid or ASA + opioid.
• Step 3 involves increasing doses of potent opioids +/- adjuvant therapy.

Drugs to Treat Pain

• Non-opioid Analgesics: NSAIDs like salicylates (aspirin) and ibuprofen, second-generation NSAIDs like celecoxib, and analgesics like acetaminophen.
• Opioids: Pure Opioid Agonists like morphine and fentanyl.
• Opioids (cont.): Methadone, meperidine, codeine, oxycodone.
• Agonist-antagonist Opioids: Pentazocine, antagonists include Naloxone.
• Miscellaneous Pain Medications: migraine (sumatriptan, ergotamine), anti-gout (colchicine, allopurinol).

Key Drug Categories

• Non-opioids
• Opioids
• Miscellaneous migraine and gout medications.

Nonopioid Analgesics

• Differ from opioids due to their ceiling effect.
• Characterized by no tolerance, and no physical or psychological dependence.
• Have antipyretic properties.
• Their primary mechanism prevents the formation of prostaglandins by inhibiting the COX enzyme, except for tramadol and clonidine.
• Used to treat mild to moderate pain.

Types of Nonopioid Analgesics

• NSAIDs: First generation (salicylates like aspirin, ibuprofen), second generation (celecoxib).
• Acetaminophen (Tylenol).

Aspirin and NSAIDs: Action Mechanism

• Gastric protection, vasodilation.
• Maintains renal support and vasodilation.
• Platelet aggregation.
• Vasodilation, inflammation, pain.
• Colorectal cancer promotion.

Aspirin and NSAIDs: Mechanisms of Action

• Aspirin: Irreversibly inhibits both COX-1 and COX-2 enzyme, and is OTC.
• First generation NSAIDs: Reversibly inhibit both COX-1 and COX-2, including ibuprofen, naproxen, and ketoprofen available OTC.
• Second generation NSAIDs: Reversibly inhibit only COX-2, Rx only.

ASA/NSAIDs: Therapeutic Uses

• Analgesic, effective for mild to moderate pain.
• Treats inflammatory disorders like dysmenorrhea and osteoarthritis.
• It can be synergistic with opioids.
• Antipyretic, reduces fever by inhibiting prostaglandin formation caused by infection-induced interleukin I release.

Therapeutic Uses of ASA/NSAIDs

• Include anti-inflammatory effects and the ability to block prostaglandins responsible for inflammation.
• Aspirin ONLY inhibits thromboxane A2 and prostacyclin-mediated platelet aggregation.
• ASA and NSAIDs prevent MI/stroke.
• Thromboxane activity is inhibited for the life of the platelet (8 days).
• Prostacyclin is inhibited for several hours.

Individual Variation Factors with Aspirin/NSAIDs

• Hypersensitivity to any Aspirin/NSAID.
• A history of GI intolerance or ulcers.
• Renal dysfunction and bleeding disorders.
• Pregnancy.
• Drug interactions (Warfarin, heparin, glucocorticoids).

Aspirin: Adverse Effects

• Gastrointestinal issues, including distress, heartburn, and nausea, plus occult bleeding.
• Bleeding, contraindicated for patients with bleeding disorders.
• Renal impairment is possible, but acute and reversible.
• Reye’s Syndrome can occur.
• Adverse effects during pregnancy.
• Hypersensitivity, which is contraindicated.
• Salicylism (tinnitus, sweating, headache, and dizziness).

Aspirin Poisoning: Safety Concerns

• Overdose is a common cause of salicylism.
• Symptoms include respiratory alkalosis progressing to respiratory depression, acidosis, hyperthermia, sweating, dehydration, electrolyte imbalance, coma, and death.
• Treatment: Supportive measures such as pumping the stomach, activated charcoal, cooling, administering fluids, and bicarbonate IV.

Ibuprofen: Action and Use

• Ibuprofen reversibly inhibits COX1 and COX2.
• Ibuprofen provides therapeutic action for inflammatory conditions, causing pain, and fever.

Ibuprofen (Motrin®, Advil®): Adverse Effects

• Gastrointestinal: distress, heartburn, nausea, occult bleeding.
• Renal impairment, cross-hypersensitivity to aspirin, and adverse effects during pregnancy.
• Cardiovascular risk and Stevens-Johnson Syndrome (SJS).
• Maximum amount/day: OTC (1200mg/day), prescription (3200mg/day).

Celecoxib (Celebrex®): Action and Adverse Effects

• Celecoxib inhibits COX2 with therapeutic action for osteoarthritis and acute pain.
• Adverse Effects: GI distress, heartburn, nausea, occult bleeding, CV risk, renal impairment, hypersensitivity to aspirin, sulfonamide allergy, and AEs during pregnancy.

Acetaminophen (Tylenol®): Action and Dosage

• Inhibits COX in the CNS only.
• Therapeutic uses include analgesic and antipyretic effects.
• Dosage: 325 mg – 1,000 mg every 4-6 hours for adults.
• Max dose: 4,000 mg per day for adults; outpatient recommended max dose is 3,000 mg/day.

Acetaminophen (Tylenol®): Adverse Effects

• Well tolerated at normal doses, but rare anaphylaxis reactions, skin reactions, and acute hepatotoxicity at doses over 4 g/day.

Medications Containing Acetaminophen

• Over-the-counter: Excedrin, Midol, Nyquil.
• Prescription: Hydrocodone, Tylox, Percocet.

Acetaminophen: Overdose Toxicity

Acetaminophen Overdose: Emergency Information

• Maryland Poison Control: (800) 222-1222
• Antidote: acetylcysteine (Acetadote® Mucomyst®).
• Administer ASAP after overdose.
• May be considered up to 24 hours after acute ingestion.

Acetaminophen: Nursing Implications

• Max dose is 4,000 mg/day from all sources.
• Do not drink alcohol; 2,000 mg per day maximum if consuming alcohol.
• Avoid with liver disease and caution about combination products.