Pain Management: Acute vs Chronic Pain

Acute vs Chronic Pain

• Acute pain has a sudden onset and usually subsides once treated
• Chronic pain is persistent or recurring and lasts 3 to 6 months, often difficult to treat
• Tolerance and physical dependence can occur in chronic pain management

Adjuvant Drugs

• Assist primary drugs in relieving pain
• Examples include NSAIDs, antidepressants, anticonvulsants, and corticosteroids
• Adjuvant drugs can be used to treat neuropathic pain, such as amitriptyline and gabapentin or pregabalin

Opioid Ceiling Effect

• A drug reaches a maximum analgesic effect, and further dose increases do not improve analgesia
• Examples include pentazocine and nalbuphine

Opioid Drugs

• Main use: to alleviate moderate to severe pain
• Often given with adjuvant analgesic drugs to assist primary drugs with pain relief
• Other uses include cough center suppression, treatment of diarrhea, and balanced anesthesia
• Contraindications: known drug allergy, severe asthma, use with extreme caution in patients with respiratory insufficiency, elevated intracranial pressure, morbid obesity or sleep apnea, paralytic ileus, and pregnancy
• Adverse effects: CNS depression, respiratory depression, nausea and vomiting, urinary retention, diaphoresis and flushing, pupil constriction, constipation, and itching
• Management of overdose: naloxone (Narcan) and naltrexone (ReVia)
• Withdrawal symptoms: anxiety, irritability, chills and hot flashes, joint pain, lacrimation, rhinorrhea, diaphoresis, nausea, vomiting, abdominal cramps, diarrhea, and confusion

Opioid Tolerance, Physical Dependence, and Psychologic Dependence

• Opioid tolerance: a common physiologic result of chronic opioid treatment, requiring larger doses to maintain analgesia
• Opioid physical dependence: a physiologic adaptation of the body to the presence of an opioid, leading to withdrawal symptoms when the drug is stopped
• Opioid psychologic dependence: a pattern of compulsive drug use characterized by a continued craving for an opioid and the need to use the opioid for effects other than pain relief

Opioid Analgesics: Interactions

• Interactions with alcohol, antihistamines, barbiturates, benzodiazepines, monoamine oxidase inhibitors, and other drugs

Specific Opioid Analgesics

• Codeine sulfate: opioid agonist, natural opiate alkaloid, often combined with acetaminophen, Schedule III, commonly used as an antitussive drug
• Fentanyl: synthetic opioid, Schedule II, used to treat moderate to severe pain, available in various forms
• Hydromorphone (Dilaudid): very potent opioid analgesic, Schedule II drug, equivalent to 7 mg of morphine
• Methadone hydrochloride (Dolophine): synthetic opioid analgesic, Schedule II, used in methadone maintenance programs, prolonged half-life can cause unintentional overdoses and deaths
• Morphine sulfate: naturally occurring alkaloid, Schedule II controlled substance, indication: severe pain, high abuse potential
• Oxycodone hydrochloride: analgesic agent structurally related to morphine, Class II, comparable analgesic activity to morphine, often combined with acetaminophen or aspirin

Nonopioid Analgesics

• Acetaminophen (Tylenol): analgesic and antipyretic effects, little to no antiinflammatory effects, available OTC and in combination products with opioids
• Mechanism of action: blocks pain impulses peripherally by inhibiting prostaglandin synthesis
• Indications: mild to moderate pain, fever, alternative for those who cannot take aspirin products
• Dosage: maximum daily dose for healthy adults is being lowered to 3000 mg/day, 2000 mg for older adults and those with liver disease
• Contraindications/interactions: drug allergy, liver dysfunction, possible liver failure, G6PD deficiency, hepatotoxic drugs, and alcohol
• Overdose management: acetylcysteine regimen
• Tramadol hydrochloride (Ultram): centrally acting analgesic with a dual mechanism of action, indicated for moderate to moderately severe pain, adverse effects similar to opioids
• Lidocaine: topical anesthetic, indications: postherpetic neuralgia, minimal adverse effects, skin irritation may occur

Nursing Process Assessment

• Obtain a thorough history regarding allergies, medications, health history, and medical history
• Perform a thorough pain assessment including pain intensity, character, location, description, precipitating and relieving factors, and type of remedies and other pain treatments
• Pain is considered a fifth vital sign
• Assess for potential contraindications and drug interactions

Nursing Implications

• Be sure to medicate patients before pain becomes severe to provide adequate analgesia and pain control
• Include pharmacologic and nonpharmacologic approaches in pain management
• Instruct patients to notify physicians about signs of allergic reaction or adverse effects
• Ensure safety measures, such as keeping side rails up, to prevent injury
• Monitor for adverse effects, including respiratory depression, and therapeutic effects, including decreased complaints of pain and improved activities of daily living

Understand the differences between acute and chronic pain, and how adjuvant drugs assist in relieving pain. Learn about the opioid ceiling effect and its implications.