Where should a 21‑month‑old child receive an intramuscular ceftriaxone (Rocephin) injection?

Intramuscular Ceftriaxone Administration Site for a 21-Month-Old Child

Administer the intramuscular ceftriaxone injection in the anterolateral aspect of the thigh (vastus lateralis muscle) for a 21-month-old child. 1

Recommended Injection Site

• The anterolateral thigh is the appropriate and preferred location for intramuscular injections in children aged 21 months. 1, 2
• The CDC and American Academy of Pediatrics explicitly endorse the anterolateral thigh as the standard injection site for vaccines and medications in infants and young children, including toddlers up to approximately 3 years of age. 1, 2

Why Not the Deltoid Muscle?

• The deltoid muscle is contraindicated in a 21-month-old child because it lacks sufficient muscle mass at this age. 1
• The deltoid muscle should only be used for intramuscular injections in children aged 3 years and older when adequate muscle mass has developed. 1, 2
• Using the deltoid in younger children risks subcutaneous deposition rather than true intramuscular administration, reducing drug absorption and efficacy. 1

Injection Technique

• Insert the needle at a 90-degree angle to ensure proper intramuscular placement in the anterolateral thigh. 2
• Use appropriate needle gauge (typically 22-25 gauge) and length to ensure penetration into muscle tissue rather than subcutaneous fat. 1
• Inject the medication well within the body of the vastus lateralis muscle to avoid inadvertent subcutaneous injection. 3

Dosing Considerations for This Age Group

• For pediatric patients, the typical ceftriaxone dose for skin and soft tissue infections is 50-75 mg/kg given once daily, not to exceed 2 grams total daily dose. 3
• For acute otitis media, a single intramuscular dose of 50 mg/kg (not to exceed 1 gram) is recommended. 3
• After reconstitution for intramuscular use, concentrations of 250 mg/mL or 350 mg/mL are standard depending on the diluent volume used. 3

Common Pitfalls to Avoid

• Never use the buttock for ceftriaxone administration due to potential sciatic nerve injury and decreased drug absorption. 1
• Do not attempt deltoid injection in children under 3 years of age, as this risks inadequate muscle penetration. 1, 2
• Avoid using diluents containing calcium (such as Ringer's solution or Hartmann's solution) for reconstitution, as particulate formation can result. 3