LESI LESI Pharmacology 2 — Questions and Answers
Question 1: How long does the anti-inflammatory effect of a single epidural corticosteroid injection typically last?
- 24-48 hours
- 1-3 weeks (Correct answer)
- 3-6 months
- 1-2 years
Correct answer: 1-3 weeks
The clinical anti-inflammatory effect of epidural corticosteroids generally lasts 1-3 weeks, though symptom relief may persist longer due to interruption of the pain cycle.
Question 2: What is the FDA's current regulatory status of corticosteroid use for epidural injection?
- Fully FDA-approved with specific epidural indication
- Off-label use — not approved for epidural administration (Correct answer)
- Approved only for caudal route
- Banned for epidural use since 2014
Correct answer: Off-label use — not approved for epidural administration
No corticosteroid is currently FDA-approved for epidural administration; their use via this route is off-label, and the FDA requires a warning label about this.
Question 3: Systemic absorption of epidural corticosteroids can suppress the hypothalamic-pituitary-adrenal (HPA) axis for approximately how long?
- 12-24 hours
- 1-3 days
- 1-3 weeks (Correct answer)
- 6-12 months
Correct answer: 1-3 weeks
Epidural corticosteroids are absorbed systemically and can suppress the HPA axis for approximately 1-3 weeks, which is clinically relevant in diabetic or immunocompromised patients.
Question 4: Which contrast agent is used to confirm epidural needle placement under fluoroscopy before steroid injection?
- Gadolinium
- Non-ionic iodinated contrast (e.g., iohexol) (Correct answer)
- Barium sulfate
- Methylene blue
Correct answer: Non-ionic iodinated contrast (e.g., iohexol)
Non-ionic iodinated contrast agents such as iohexol (Omnipaque) are used epidurally because they are non-neurotoxic and allow real-time fluoroscopic confirmation of spread pattern.
Question 5: The maximum recommended number of lumbar ESI injections in a 12-month period per most clinical guidelines is:
- 1-2 injections
- 3-4 injections (Correct answer)
- 5-6 injections
- Unlimited as needed
Correct answer: 3-4 injections
Most pain management societies recommend limiting lumbar ESIs to 3-4 injections per year to minimize cumulative steroid side effects including osteoporosis and HPA axis suppression.
Question 6: Betamethasone sodium phosphate is classified as which type of steroid particle?
- Particulate
- Non-particulate (soluble) (Correct answer)
- Semi-particulate
- Crystalline aggregate
Correct answer: Non-particulate (soluble)
Betamethasone sodium phosphate is a non-particulate, water-soluble formulation and is considered safer than particulate steroids for transforaminal injections.
LESI LESI Pharmacology 2
How long does the anti-inflammatory effect of a single epidural corticosteroid injection typically last?