What are the recommended dosages and precautions for dexamethasone and Kenalog (triamcinolone) shots?

Dexamethasone and Kenalog (Triamcinolone) Injection Dosing and Precautions

Dexamethasone and Kenalog are not interchangeable—they have different potencies, durations of action, and clinical applications that require indication-specific dosing.

Dexamethasone Dosing by Indication

Chemotherapy-Induced Nausea/Vomiting

• High emetic risk chemotherapy: 12 mg oral or IV on day 1, followed by 8 mg daily on days 2-4 1
• Moderate emetic risk chemotherapy: 8 mg oral or IV on day 1, followed by 8 mg daily on days 2-3 1
• Low emetic risk chemotherapy: Single 8 mg oral or IV dose 1
• Breakthrough nausea/vomiting: 12 mg oral or IV daily 1

Other Indications

• Immune thrombocytopenic purpura: 40 mg oral or IV daily (significantly higher than antiemetic dosing) 2
• Throat pain: 10 mg oral or IV as a single dose 3

Route of Administration

• Oral and IV dexamethasone are equivalent with 1:1 conversion (e.g., 8 mg IV = 8 mg oral) 2, 3, 4
• IV administration should be given slowly over several minutes to avoid perineal burning 2
• If perineal burning occurs during IV push, slow or temporarily pause the infusion 2

Kenalog (Triamcinolone Acetonide) Dosing by Indication

Systemic (Intramuscular) Administration

• Initial dose: 60 mg injected deeply into the gluteal muscle 5
• Usual range: 40-80 mg depending on patient response and duration of relief 5
• Some patients may be controlled on doses as low as 20 mg 5
• Hay fever/pollen asthma: Single injection of 40-100 mg may provide remission throughout pollen season 5
• Severe chronic asthma (elderly patients): High-dose regimen of 360 mg IM has shown effectiveness in steroid-dependent patients, though this is off-label and requires careful patient selection 6

Intra-articular Administration

• Smaller joints: 2.5-5 mg per injection 5
• Larger joints: 5-15 mg per injection 5
• Adults may require up to 10 mg for smaller areas and up to 40 mg for larger areas 5
• Multiple joints: Single injections into several joints up to a total of 80 mg have been given 5
• A single local injection is frequently sufficient, but several injections may be needed 5

Administration Technique

• Strict aseptic technique is mandatory 5
• Shake vial before use to ensure uniform suspension 5
• Inspect for clumping or granular appearance (agglomeration)—discard if present 5
• Inject without delay after withdrawal to prevent settling in syringe 5
• For IM injections, use minimum needle length of 1½ inches in adults; longer needles may be required in obese patients 5
• Inject deeply into gluteal muscle to avoid subcutaneous fat atrophy 5
• For intra-articular injections, aspirate excessive synovial fluid before injection 5
• Avoid injecting into surrounding tissues, particularly in deltoid region, as this may lead to tissue atrophy 5

Potency Comparison

Equivalent anti-inflammatory doses (for reference only—not for direct substitution): 5

• Cortisone 25 mg = Triamcinolone 4 mg = Dexamethasone 0.75 mg
• Hydrocortisone 20 mg = Triamcinolone 4 mg = Dexamethasone 0.75 mg
• Prednisone 5 mg = Triamcinolone 4 mg = Dexamethasone 0.75 mg

These dose relationships apply only to oral or IV administration; when injected IM or intra-articularly, relative properties may be greatly altered 5

Critical Precautions and Pitfalls

Dexamethasone-Specific

• Do not confuse indication-specific doses: throat pain (10 mg), antiemetic (8-20 mg), and ITP (40 mg) require different dosing 2, 3
• Consider antifungal prophylaxis in patients receiving prolonged steroid therapy 2
• When used with aprepitant for chemotherapy-induced nausea, reduce dexamethasone dose to 12 mg on day 1 and 8 mg on days 2-4 due to drug interaction 1

Kenalog-Specific

• Postinjection flare: Acute inflammatory response can occur 2 hours after injection, mimicking septic arthritis with severe pain, swelling, and inability to ambulate 7
• Synovial fluid may appear "butterscotch"-colored and contain triamcinolone crystals visible on polarized light microscopy 7
• Subcutaneous fat atrophy occurs if injection is not properly placed deep into muscle 5
• Tissue atrophy can occur if suspension is injected into surrounding tissues rather than joint space 5
• Side effects with repeated IM use include weight gain, menstrual disturbances, hypertension, edema, and spontaneous ecchymoses (observed in 13.8% of patients) 8
• High-dose IM triamcinolone (360 mg) can cause transient weakness and diabetes in the first week 6

General Corticosteroid Precautions

• Gradual withdrawal is essential after long-term therapy—do not stop abruptly 5
• Dosage adjustments may be necessary during remissions, exacerbations, or stressful situations 5
• Contains benzyl alcohol—use caution in neonates and infants 5
• Avoid entering blood vessels during injection 5

Comparative Efficacy

• Intra-articular dexamethasone (8 mg) and triamcinolone hexacetonide (40 mg) show comparable efficacy for knee arthritis in rheumatoid arthritis, with similar reduction in swelling and pain at 1 and 3 weeks 9
• Dexamethasone provides faster pain relief (2.3 days) compared to triamcinolone (3.4 days), though this difference is not clinically significant 9
• Both agents have similar low relapse rates at 6 months (6.7% for dexamethasone vs 9.4% for triamcinolone) 9