A nurse prepares to administer 1.6 mL of medication intramuscularly to a 4-month-old infant. Which action should the nurse include?

• A. Divide the medication into two injections with volumes under 1 mL
• B. Inject all 1.6 mL into a single site
• C. Give the dose subcutaneously instead
• D. Dilute the medication to 3 mL total volume

Answer: (A)

Infants have limited muscle mass, so the amount given in a single intramuscular injection should be small to avoid tissue damage and ensure good absorption. When a dose totals more than what one site can safely hold, it should be divided into multiple injections at separate sites, with each injection staying within the safe per-site volume. For a 4-month-old, this means splitting the 1.6 mL dose into two injections rather than delivering it all at one site.

Administering the entire dose at one site could overwhelm the tissue and increase discomfort or injury and may not be absorbed properly. Giving the dose via subcutaneous tissue would change the intended route and how the drug acts. Diluting to reach a larger total volume (such as 3 mL) is not appropriate because it alters the concentration and dosing accuracy and is not a standard practice for adjusting IM volumes.