How should I reconstitute powdered corticosteroid (e.g., triamcinolone acetonide) for a subacromial injection?

Reconstitution of Powdered Triamcinolone for Subacromial Injection

For subacromial shoulder injection, use triamcinolone acetonide 40 mg without reconstitution if using a pre-mixed suspension, or if you have powdered triamcinolone, reconstitute it with sterile normal saline or sterile water for injection to achieve a final concentration of 40 mg/mL, then inject the appropriate volume (typically 1 mL = 40 mg total dose) into the subacromial space. 1

Understanding the Product Form

Most triamcinolone acetonide products come as pre-mixed suspensions rather than true powders requiring reconstitution. 2 The vial contains a suspension that has settled and appears as white precipitate, which is normal. 2

Critical Pre-Injection Steps

• Shake the vial vigorously before withdrawing to ensure uniform suspension of the medication. 2
• Inspect for agglomeration (clumping or granular appearance with white precipitate separated from solution) - if present, discard the vial and do not use it. 2
• Inject immediately after withdrawal to prevent settling in the syringe. 2

Dosing for Subacromial Injection

The standard dose is 40 mg of triamcinolone acetonide for shoulder injections, whether targeting the subacromial space or glenohumeral joint. 1 This translates to 1 mL if using a 40 mg/mL concentration.

If True Reconstitution Is Required

If you genuinely have a powdered form (rare for triamcinolone acetonide):

• Reconstitute with sterile normal saline to achieve 40 mg/mL concentration. 1
• For example, if you have 40 mg powder, add 1 mL sterile normal saline.
• Mix thoroughly until completely dissolved.
• Use immediately after reconstitution.

Dilution for Lower Concentrations (Not Typically Needed for Shoulder)

While not standard for subacromial injection, triamcinolone can be diluted with sterile normal saline for other indications:

• 10 mg/mL for acne or inflammatory conditions 1
• 5 mg/mL for more superficial dermatologic lesions 1

Administration Technique

• Use strict aseptic technique - this is mandatory. 2
• For intramuscular or deep injections, use a minimum 1½ inch needle in adults; longer needles may be required in obese patients. 2
• Inject deeply into the intended space (subacromial bursa or joint). 2
• Avoid injecting into surrounding tissues, as this can cause tissue atrophy. 2

Critical Pitfalls to Avoid

• Never inject if agglomeration is present - the separated white precipitate indicates the product is unusable. 2
• Do not inject into sites with active infection (impetigo, herpes, cellulitis). 1
• Avoid injecting into the tendon substance itself - target the bursa or joint space, not the rotator cuff tendon. 2
• Do not delay injection after drawing up - the suspension will settle in the syringe. 2

Expected Duration of Effect

A single injection is often sufficient for acute conditions, though the evidence for long-term pain reduction in shoulder pathology is not well established. 1 Repeat injections may be considered if symptoms recur, typically spaced at least 3-4 weeks apart. 1