Overview
This lecture reviews various analgesics, including an anticonvulsant, opioid and topical analgesics, and vascular headache suppressants, focusing on uses, actions, side effects, and key nursing considerations.
Anticonvulsant Analgesic: Pregabalin
- Pregabalin (Lyrica) treats neuropathy, fibromyalgia, restless-leg syndrome, and sometimes seizures.
- Acts by binding to calcium channels in the CNS, decreasing excitatory neurotransmitter release (not an opioid).
- Side effects: drowsiness, dry mouth, dizziness, edema.
- Advise patients to avoid alcohol (increased CNS depression) and taper off gradually if discontinuing.
Opioid Analgesics
- Common opioids: fentanyl, morphine, Dilaudid, oxycodone.
- Used for moderate to severe pain; work by binding to CNS opioid receptors.
- Major side effects: respiratory depression (most serious), sedation, constipation, GI upset, hypotension, urinary retention.
- Black box warning for respiratory depression, abuse, and addiction risk.
- Monitor pain, vital signs, and respiratory status; administer IV opioids slowly.
- Naloxone (Narcan) is the antidote; reverses effects but may cause hypertension, tachycardia, agitation.
- "RUSH" mnemonic for key side effects: Respiratory depression, Urinary retention, Sedation, Hypotension.
Topical Analgesics: Lidocaine
- Used for numbing skin/mucous membranes in procedures like wound dressing changes.
- Blocks local pain impulse conduction.
- Side effects: rare, may include stinging or local erythema.
- Emla cream (contains lidocaine) often used before IV insertion in children; apply with occlusive dressing for 1 hour, then clean before procedure.
Vascular Headache Suppressants
- Ergotamine and sumatriptan treat migraine and cluster headaches.
- Act by causing vasoconstriction of intracranial blood vessels.
- Ergotamine side effects: GI upset, hypertension; sumatriptan: dizziness, vertigo, tingling.
- Both drugs have black box warnings; contraindicated in ischemic coronary artery or peripheral vascular disease.
- Migraine teaching: rest in dark, quiet place; avoid alcohol and tyramine-rich foods (aged cheese, smoked meats, avocado, red wine, chocolate).
Key Terms & Definitions
- Neuropathy — nerve pain, often chronic and difficult to treat.
- Opioid agonist — drug that activates opioid receptors to relieve pain.
- Naloxone (Narcan) — medication used to reverse opioid overdose.
- Vasoconstriction — narrowing of blood vessels, reducing blood flow.
- Tyramine — compound in certain foods that can trigger migraines.
Action Items / Next Steps
- Review medications for glaucoma in the next lecture.
- Study and memorize side effects, black box warnings, and key nursing actions for each medication class covered.
- Prepare for NCLEX/nursing exam questions on these analgesics.