What intravenous (IV) pain medications can be given for severe sciatica?

IV Pain Medications for Severe Sciatica

For severe sciatica requiring IV analgesia, use IV ketorolac 15 mg every 6 hours (maximum 5 days) as first-line therapy, or IV morphine 0.1-0.2 mg/kg every 4 hours if ketorolac is contraindicated or inadequate. 1, 2, 3

First-Line IV Therapy: Ketorolac

Ketorolac is the preferred IV NSAID for acute severe pain when oral medications have failed or cannot be tolerated. 1, 2

Dosing Protocol

• Adults 17-64 years: 15-30 mg IV every 6 hours, maximum 120 mg/day 1, 2
• Adults ≥65 years, renally impaired, or <50 kg: 15 mg IV every 6 hours only 2
• Maximum duration: 5 days total 1, 2
• Lower doses (7.5-15 mg) provide equivalent analgesia to higher doses (30 mg) with better safety profile 4, 5

Critical Contraindications

Ketorolac is absolutely contraindicated in patients with: 1, 2

• Active or history of peptic ulcer disease or GI bleeding
• Age >60 years with significant alcohol use or hepatic dysfunction
• Compromised fluid status, dehydration, or renal insufficiency
• Thrombocytopenia or concurrent anticoagulant/antiplatelet therapy
• Aspirin/NSAID-induced asthma
• Cerebrovascular bleeding or high cardiovascular risk

Mandatory Monitoring

Before initiating ketorolac, obtain baseline: 1, 2

• Blood pressure, BUN, creatinine
• Liver function tests (alkaline phosphatase, LDH, SGOT, SGPT)
• Complete blood count
• Fecal occult blood

Discontinue immediately if: 1, 2

• BUN or creatinine doubles
• Hypertension develops or worsens
• Liver function tests increase >3× upper limit of normal
• Any signs of GI bleeding

Clinical Limitations

• Onset of action is delayed 30-60 minutes 1, 6
• >25% of patients exhibit little or no analgesic response 6
• Most useful as adjunct to opioids rather than monotherapy for severe pain 6, 4

Second-Line IV Therapy: Morphine

When ketorolac is contraindicated or provides inadequate relief, IV morphine is the standard opioid for severe sciatica. 3

Dosing Protocol

• Initial dose: 0.1-0.2 mg/kg IV every 4 hours as needed 3
• Adjust based on pain severity, adverse events, patient age, and size 3
• Rapid IV administration may cause chest wall rigidity 3

Critical Warnings

• Respiratory depression is the most serious adverse reaction 3
• High doses may cause sympathetic hyperactivity, increased catecholamines, and convulsions 3
• May cause hypotension in ambulatory patients 3
• Contraindicated in bronchial asthma, upper airway obstruction, and paralytic ileus 3

Drug Interactions

• CNS depressants increase risk of respiratory depression, hypotension, sedation, or death 3
• Muscle relaxants may enhance neuromuscular blockade and cause respiratory depression 3
• Anticholinergics increase risk of urinary retention and severe constipation 3

Adjunctive Therapy for Neuropathic Component

Sciatica is a mixed pain syndrome with both nociceptive and neuropathic components; IV analgesics alone may be insufficient. 7

Add Gabapentinoids for Neuropathic Pain

Once acute pain is controlled with IV medications, transition to oral adjuvants: 1

• Gabapentin: Start 100-200 mg/day, titrate to 900-3600 mg/day in divided doses 1
• Pregabalin: Start 25-50 mg/day, titrate to 150-600 mg/day in two divided doses 1
• Evidence supports gabapentin for radiculopathy with fair quality 1

Alternative IV NSAID Options

If ketorolac is unavailable but IV NSAID therapy is appropriate:

• Ibuprofen: 400-800 mg IV every 6 hours, maximum 3200 mg/day 1, 8
• Never combine ketorolac with other NSAIDs - toxicities are additive without additional analgesic benefit 2

Critical Clinical Pitfalls

Common Errors to Avoid

• Do not use systemic corticosteroids - good evidence shows they are ineffective for sciatica 1
• Do not exceed 5-day duration for ketorolac - risk-benefit ratio deteriorates significantly with prolonged use 1, 2
• Do not use ketorolac as monotherapy for severe pain - it works best as adjunct to opioids 6, 4
• Do not assume all patients respond to ketorolac - >25% show minimal response 6

Transition Planning

• Begin oral medications before discontinuing IV therapy to prevent pain recurrence 1
• If pain persists beyond acute phase, investigate for underlying treatable causes rather than continuing IV analgesics 8
• Consider multimodal approach combining NSAIDs, gabapentinoids, and physical modalities for chronic symptoms 1