Pain Management and Treatment of Headaches
Types of Pain
Acute Pain: Sudden onset, usually due to injury or surgery; resolves with healing.
Chronic Pain: Persists beyond normal healing time (>3 months); often associated with
conditions like arthritis.
Nociceptive Pain: Caused by tissue damage; divided into somatic (skin, muscle, bone)
and visceral (organs, deep structures).
Neuropathic Pain: Result of nerve damage; includes diabetic neuropathy and
postherpetic neuralgia.
Malignant Pain: Associated with cancer; often requires multimodal management.
Non-Pharmacologic Pain Management
Physical therapy, acupuncture, cognitive behavioral therapy (CBT), transcutaneous
electrical nerve stimulation (TENS), ice/heat therapy.
WHO Three-Step Ladder for Pain Management
1. Mild Pain: Non-opioid analgesics (NSAIDs, acetaminophen).
2. Moderate Pain: Weak opioids (tramadol, codeine) +/- non-opioids.
3. Severe Pain: Strong opioids (morphine, fentanyl) +/- non-opioids.
NSAIDs
MOA: Inhibit cyclooxygenase (COX-1, COX-2) enzymes, reducing prostaglandin
synthesis.
Adverse Effects: GI ulcers, renal toxicity, cardiovascular risk.
Contraindications: GI bleeding, renal impairment, CV disease.
Ceiling Effect: No additional pain relief beyond a certain dose.
Acetaminophen (APAP)
MOA: Inhibits prostaglandin synthesis in the CNS.
Indications: Fever, mild-to-moderate pain.
Max Dose: 4g/day (general), 3g/day (elderly/liver disease).
Precautions: Hepatotoxicity risk, avoid in severe liver disease.
Opioids
, MOA: Bind to opioid receptors (mu, delta, kappa) in the CNS, inhibiting pain pathways.
Common Adverse Effects: Respiratory depression, constipation, tolerance, dependence.
Management of Adverse Effects: Naloxone for overdose, laxatives for constipation.
Equianalgesic Dosing: Adjusting doses when switching opioids to maintain equivalent
pain relief.
Migraine and Cluster Headaches
IHS Classification:
o Migraine without Aura: Unilateral, pulsating, moderate/severe pain, aggravated
by activity.
o Migraine with Aura: Visual disturbances preceding headache.
o Cluster Headaches: Severe, unilateral periorbital pain, autonomic symptoms
(lacrimation, nasal congestion).
Migraine Management
Abortive Therapy: Triptans, NSAIDs, antiemetics, ergots.
Preventive Therapy: Beta-blockers, anticonvulsants, CGRP inhibitors.
Triggers: Stress, caffeine, alcohol, hormonal changes, lack of sleep.
Red Flags
1. Sudden onset ("Thunderclap" headache)
o Severe headache reaching peak intensity within seconds to minutes
o Concern for subarachnoid hemorrhage (SAH)
2. New onset after age 50
o Increased risk of secondary causes, such as temporal arteritis, stroke, or
malignancy
3. Worst headache of life
o Needs urgent imaging to rule out SAH, meningitis, or tumor
4. Progressive worsening over time
o Suggests mass effect, increased intracranial pressure (ICP), or chronic
subdural hematoma
5. Neurologic deficits (focal signs)
o Weakness, numbness, vision changes, ataxia, confusion, speech difficulties