What is the appropriate intramuscular (IM) dose of Decadron (dexamethasone) for an 11.25 kg male who cannot take medication orally?

Dexamethasone IM Dosing for 11.25 kg Pediatric Patient

For an 11.25 kg child who cannot take oral medication, administer dexamethasone 2.25 mg IM (0.2 mg/kg), which is the standard pediatric dose for most acute conditions requiring corticosteroid therapy. 1

Weight-Based Dosing Calculation

• Standard pediatric dosing: 0.2 mg/kg/24 hours in divided doses 1
• For this 11.25 kg patient: 0.2 mg/kg × 11.25 kg = 2.25 mg per dose
• The FDA label specifies that "the smallest effective dose should be used in children, preferably orally. This may approximate 0.2 mg/kg/24 hours in divided doses" 1

Route Equivalency

• IM and oral dexamethasone are bioequivalent with 1:1 dosing conversion 2, 3
• No dose adjustment is needed when switching between IM and oral routes 3, 4
• Once the patient can tolerate oral intake, transition to the same 2.25 mg dose orally 3

Indication-Specific Considerations

For Acute Asthma Exacerbation

• Initial dose: 1-2 mg/kg PO/IM (maximum 60 mg) 5
• For this patient: 11.25-22.5 mg as initial dose
• Subsequent dosing: 1-2 mg/kg per day divided in 1-2 doses for 3-10 days (maximum 60 mg/day) 5
• No advantage of IM over oral route if GI absorption is intact 5
• No need to taper if used for less than 10 days 5

For Adrenal Insufficiency

• Initial dose: 2-3 mg/kg IV/IM (maximum 100 mg) over 3-5 minutes 5
• For this patient: 22.5-33.75 mg initial dose
• Followed by: 1-5 mg/kg every 6 hours for infants or 12.5 mg/m² every 6 hours for older children 5
• Strongly consider concomitant fluid bolus of 20 mL/kg of D5NS or D10NS during first hour 5

For Allergic Reactions/Rash

• Standard symptomatic treatment dose would be 0.2 mg/kg = 2.25 mg IM 2
• Corticosteroids are commonly used alongside antihistamines for acute allergic-type rashes 2

Administration Technique

• Administer slowly over several minutes to avoid adverse reactions 4
• Monitor for hyperglycemia, especially if repeated doses are needed 4
• Inspect solution for particulate matter and discoloration before administration 1

Common Pitfalls to Avoid

• Do not underdose: The FDA label specifically warns "Do not underdose" for pediatric patients requiring corticosteroids 5, 1
• Do not confuse with hydrocortisone equivalents: Dexamethasone 0.75 mg = hydrocortisone 20 mg = prednisolone 5 mg 5
• Do not abruptly discontinue if treatment extends beyond a few days—taper gradually 4
• Do not assume all corticosteroids have 1:1 IM-to-oral conversion—this is specific to dexamethasone 3

Monitoring Parameters

• Blood glucose levels: Hyperglycemia occurs frequently with dexamethasone therapy 4
• Clinical response: Adjust dosing based on therapeutic effect while using the smallest effective dose 1
• Duration of therapy: If treatment exceeds 48-72 hours, consider antifungal prophylaxis 4

Duration and Tapering

• For short courses (<10 days): No taper required 5
• For longer courses: Taper gradually to prevent adrenal insufficiency 4
• Adrenal suppression can occur with doses as low as 1 mg but typically resolves within 48 hours of discontinuation 4