• Most drug manuals list the recommended dosage range for medications administered to children.  However, in clinical practice most physicians use a source more specific to the neonatal or pediatric population.  Use the drug reference manuals on the pediatric / neonatal units to find the recommended safe range.
• Most commonly, safe dosage will be expressed in mg/kg/day, or whatever unit the medication is measured in.
• The two concepts to remember are: 
• Recommended dosage (what the literature states)
• Actual dosage (how much the client is receiving)
• Make sure that your evaluative information is equal, ie, single dose versus 24 hrs.

John has gentamicin 60 mg IV ordered for an infection.  The drug reference indicates that a safe single dose is 2 - 2.5 mg / kg.  If John weighs 44 lbs, is this a safe dose? 
 

Tips:

Since the reference uses kg and John’s weight is in pounds, you first must convert the 44 lbs to kg.    44 ÷ 2.2 = 20 kg.  The drug manual provides a "range"  (2-2.5) information, i.e., "minimal" and "maximum". The reference is to a "single" dose.

Minimal:        20  kg x 2 mg/kg  =    40

Maximum:      20 kg  x 2.5 mg/kg =   50 

John has an actual order for 60 mg.   Is it a safe dose?

• Recommended:      40-50 mg per dose.
• Actual order:       60 mg

(Call the doctor and question the order unless there is documented evidence such as therapeutic drug levels that indicates it is an appropriate dose.)

Example 2:

John also has an order for ampicillin sodium 395 mg IV q 6 hr.   The safe range for his type of infection in the literature is 100-200 mg /kg /day.  Is this a safe dose? 

Calculate the recommended range:

• Minimal:  100 mg  x 20 kg  = 2000 mg
• Maximal: 200 mg x 20 kg  = 4000 mg

Actual dose is:  395 x 4 (q 6 hr) = 1580 mg / day 

Compare the two values.  The actual dose is less than the recommended dose.  Dose is “safe”, but not necessarily therapeutic.