NCS Pharmacology & Pain Management — Essential Review
Central Nervous System Depressants & Sleep
CNS depressants include sedatives, hypnotics, and analgesics; safety is paramount due to respiratory and CNS effects.
Normal respiratory rate: breaths/min; assess before giving CNS depressants.
Safety considerations: dizziness, orthostatic hypotension (low BP when standing), fall risk; implement fall precautions and keep call light within reach.
Insomnia management: prioritize nonpharmacologic strategies plus prescribed meds when needed.
Nonpharmacologic: establish routine, regular wake time, avoid heavy meals before bed, limit fluids at night, minimize caffeine before bedtime (e.g., hours before sleep), relaxation techniques, dim lights, avoid loud/noisy environments.
Sleep hygiene helps restore sleep without heavy sedation.
Sleep stages (NREM I–IV, REM): REM involves dreaming; deep NREM stages important for tissue repair and homeostasis; frequent awakenings disrupt regeneration.
When sedatives/hypnotics are needed, use the lowest effective dose and shortest duration to reduce withdrawal risk and adverse effects.
Pharmacology of Sedative-Hypnotics
Barbiturates: short-, intermediate-, long-acting; long-acting half-life can be >24 hours; high risk of dependence and withdrawal; limited use for sedation/sleep.
Benzodiazepines: end with or (e.g., diazepam, lorazepam, temazepam); anxiolytic and sedative; risk of dependence, tolerance, and withdrawal; overdose treated with Flumazenil (benzodiazepine antagonist).
Nonbenzodiazepine sedatives (Ambien, Lunesta, etc.): similar safety profiles and nursing considerations as benzos/barbiturates; monitor for respiratory depression and sedation.
Antihistamines (diphenhydramine, Benadryl) and melatonin agonists: OTC options; can cause sedation; avoid combining with prescribed CNS depressants.
Antidotes: Flumazenil for benzodiazepine overdose; Narcan (naloxone) for opioid overdose.
Dosing principles: IV push should be slow (often minutes for many agents) to reduce respiratory depression and side effects.
Adverse effects common to brain-active meds: nausea/vomiting (CTZ and vomiting center in medulla); hangover effect with long-acting agents; cognitive slowing; dizziness; hypotension.
Special cautions:
Pregnancy: avoid certain CNS depressants due to fetal risk.
Elderly: heightened sensitivity; start low and go slow; monitor for delirium and falls.
Sedative-hypnotic withdrawal can be severe; abrupt cessation may cause significant symptoms; taper when clinically indicated.
Anesthesia: Balanced Anesthesia & Types
Balanced anesthesia uses a combination (cocktail) of agents to minimize exposure to any single drug and shorten recovery.
Common approach:
Minimal general anesthetic dose; use inhaled nitrous oxide and/or IV agents (barbiturates or benzodiazepines) as adjuncts.
Narcotic analgesics (e.g., midazolam, fentanyl) to enhance effect and reduce required anesthesia dose.
Muscle relaxants or paralytics may be used; airway management (intubation) as needed; may require mechanical ventilation.
Spinal vs Epidural:
Spinal anesthesia: local anesthetic injected into the spinal canal; full leg paralysis; used for certain surgeries; requires flat recovery to avoid spinal headaches.
Epidural anesthesia: local anesthetic injected above the spinal canal; numbs but preserves some movement; used in labor and post-op pain relief; walking epidural common.
Postoperative goals: minimal cardiovascular impact, reduced nausea/vomiting, quicker recovery and shorter hospital stays.
Post-anesthesia nursing: monitor vitals closely (frequently initially), assess for airway protection, gag reflex, motor/sensory status, urine output, and neurological status.
Immediate post-op priorities: ensure airway patency, prevent aspiration, and assess for respiratory depression.
Analgesics, Anti-Inflammatories & Pain Types
Pain is signaled by nociceptors throughout the body; management depends on pain type: somatic, visceral, vascular, superficial, and joint-related pain.
NSAIDs (e.g., aspirin, ibuprofen, ketorolac, naproxen) inhibit COX-1 and COX-2; reduce inflammation and pain but may cause GI irritation/bleeding and affect platelets.
COX-1 vs COX-2:
COX-1: protects stomach lining, supports platelet aggregation.
COX-2: mediates inflammation and pain.
Aspirin (ASA): COX-1/COX-2 inhibition; antiplatelet effects; GI bleeding risk; Reye’s syndrome risk in children; avoid in third trimester; monitor for bleeding signs (gum bleeding, bruising, petechiae, purpura).
Ibuprofen: COX-1/COX-2 inhibition; generally no Reye’s syndrome risk; can worsen hypertension; avoid in preop when possible; administer with food to protect stomach.
COX-2 inhibitors (e.g., celecoxib, meloxicam) designed to reduce GI risk but associated with thrombotic events; some were recalled (e.g., Vioxx) due to increased risk of stroke/MI; black box warnings applied to others.
Ketorolac: potent NSAID for short-term analgesia; GI bleeding risk; avoid in longer-term use.
Corticosteroids: powerful anti-inflammatories; require taper to prevent Addisonian crisis; long-term use can cause immunosuppression, hyperglycemia, poor wound healing; used to rapidly reduce inflammation in lungs or autoimmune diseases.
DMARDs (Disease-modifying antirheumatic drugs): immunosuppressive and immunomodulatory therapy for autoimmune diseases (e.g., rheumatoid arthritis); include monoclonal antibodies (mAbs) like infliximab, adalimumab; antimalarials like hydroxychloroquine for anti-inflammatory effects.
Antimalarials (e.g., hydroxychloroquine, chloroquine): off-label anti-inflammatory uses; caution with ocular toxicity; used for lupus, RA, Crohn’s/UC in some cases.
Gout management:
Colchicine: inhibits leukocyte migration to urate crystals; hydration and dietary restrictions to reduce uric acid load.
Avoid aspirin during gout flare; ensure adequate hydration; limit purine-rich foods; may need urate-lowering therapy in recurrent cases.
Allopurinol or other agents may be used chronically to reduce uric acid production (not detailed in this content).
Analgesic selection by pain level: start with non-narcotics and escalate; consider nonopioid adjuvants (gabapentin, pregabalin, antidepressants) for neuropathic pain; reserve narcotics for moderate-to-severe pain or cancer/palliative care.
Narcotics (opioids): morphine, hydromorphone, fentanyl; used for acute, severe pain and cancer pain; analgesia via CNS depression; caution with respiratory depression and hypotension; monitor RR, BP, sedation, and mental status.
Morphine: widely used, also used in AMI to relieve pain and improve perfusion; monitor for respiratory depression and hypotension; antidote: Narcan (naloxone).
Hydromorphone (Dilaudid): more potent and faster-acting, often associated with more rapid adverse effects; shorter duration; monitor closely.
Fentanyl: potent; transdermal patches last hours; use in controlled settings; risk of diversion (staff or family) and misuse; monitor for overdose.
PCA (Patient-Controlled Analgesia): patient self-administers small doses; generally results in lower overall opioid use; monitor vitals and sedation.
Combination analgesics: e.g., hydrocodone with acetaminophen; codeine with acetaminophen; higher risk of acetaminophen toxicity and GI effects.
Opioid safety & diversion: require vigilant nurse oversight to prevent misuse or diversion; verify all doses and monitor for adverse effects.
Antidotes & monitoring:
Naloxone for opioid overdose.
Flumazenil for benzodiazepine overdose.
Adverse effects of opioids: respiratory depression, hypotension, constipation, urinary retention, sedation; risk of CNS depression with alcohol and other depressants; assess RR prior to dosing.
Muscle relaxants (non-narcotic but CNS depressants): used for spasticity and musculoskeletal pain; potential hepatotoxicity; avoid with alcohol, prior to driving, or in myasthenia gravis; avoid in glaucoma; limit chronic use.
Adjuvant analgesics for chronic pain: gabapentin, pregabalin (nerve pain, neuropathy, fibromyalgia); antidepressants for mood and pain synergy.
Opioid-related cautions: risk of addiction, dependence, and withdrawal; careful tapering and monitoring; consider nonopioid alternatives first when appropriate.
Pain Management Nursing Process & Monitoring
Nursing responsibilities: assess the patient’s original problem, pain level, and analgesia needs; educate patients about safe use of analgesics and potential interactions.
Pain assessment: baseline and ongoing assessment; use stepped approach: start low, go slow; reassess response and adjust plan accordingly.
Monitoring plan:
Vital signs: RR, BP, heart rate; monitor for signs of respiratory depression and orthostatic changes.
GI function: monitor for constipation, GI bleeding signs with NSAIDs and opioids.
Neuro status: monitor sedation level, mental status, and alertness.
Monitor for adverse effects: nausea/vomiting, dizziness, urinary retention, itching, rash.
Teaching points for patients:
Do not combine CNS depressants without clinician guidance.
Do not mix OTC sleep aids or diphenhydramine with prescribed CNS depressants.
Avoid alcohol with sedatives, opioids, and NSAIDs due to increased risks.
Report signs of bleeding, excessive sedation, or respiratory depression immediately.
Postoperative safety goals: early ambulation to prevent DVT, pneumonia, and ileus; incentive spirometry; coughing and deep breathing; hydration and mobilization to reduce complications.
Special Topics: Nursing Implications for Gout, DMARDs & Antimalarials
Gout pathophysiology: uric acid crystal deposition in joints (commonly the big toe) and kidneys; inflammation is driven by leukocytes.
Colchicine inhibits leukocyte migration to urate crystals; hydration and avoidance of purine-rich foods recommended.
NSAIDs in gout: manage pain and inflammation; avoid aspirin during gout flare; ensure GI protection with meals and monitor for GI bleeding.
DMARDs & biologicals: used for autoimmune diseases to suppress overactive immune response; monoclonal antibodies (e.g., infliximab, adalimumab) can reduce inflammation; monitor for infection risk and screen prior to therapy.
Antimalarials in inflammation: hydroxychloroquine and chloroquine reduce inflammation; monitor for ocular toxicity and interactions with other meds.
Nutritional and lifestyle considerations: hydration, diet modification to reduce purines, and regular exercise to manage inflammation and pain.
Pregnancy considerations: avoid NSAIDs/aspirin in certain trimesters; consult obstetric guidelines for NSAID use during pregnancy.
Key Nursing Formulas & Terms (for quick recall)
Antidotes: Flumazenil (benzodiazepines), Narcan/naloxone (opioids).
PCA: patient-controlled analgesia; often morphine or hydromorphone.
Receptors: benzodiazepines act on GABA-A; opiates act on mu receptors; NSAIDs inhibit COX-1 and COX-2.
Common endpoints: goal is adequate pain relief with minimal adverse effects; monitor for respiratory depression, hypotension, and delirium, especially in elderly.
Important cautions: avoid mixing CNS depressants; monitor for signs of bleeding with NSAIDs; taper steroids to prevent adrenal crisis; assess for diversion risks with controlled substances.
Summary for Quick Recall
Always assess respiratory status before giving CNS depressants; normal RR .
Use sleep strategies and minimize pharmacologic sleep aids; reserve sedatives for appropriate cases.
Understand the differences between barbiturates, benzodiazepines, and Ambien-like drugs; know reversal agents: Flumazenil for benzos; Narcan for opioids.
In anesthesia, practice balanced techniques to reduce recovery time and adverse effects; monitor post-op vitals and airway.
For pain, start with non-narcotics (NSAIDs/acetaminophen) when possible; reserve opioids for severe pain; use PCA to optimize dosing and safety.
Monitor for NSAID-related GI bleed risk, especially with aspirin and prolonged use; consider COX-2 inhibitors cautiously due to thrombotic risk.
Steroids require taper to avoid Addisonian crisis; monitor glucose and infection risk.
DMARDs and biologics suppress immunity; screen for infection risk and monitor for adverse effects.
Post-op: promote ambulation and pulmonary hygiene to prevent DVT, pneumonia, and ileus.