How many mL should be administered for benzathine penicillin G 1,200,000 units if available in 600,000 units/mL?

To determine the correct volume of benzathine penicillin G to administer, you need to consider the total required dose and the concentration available. In this case, the order is for 1,200,000 units, and the drug is available at a concentration of 600,000 units per mL.

The calculation involves using the following formula:

Volume to administer (mL) = Desired dose (units) / Concentration (units/mL)

Plugging in the values:

Volume to administer = 1,200,000 units / 600,000 units/mL

Volume to administer = 2 mL

This means that to deliver the ordered dose of 1,200,000 units, the nurse should administer 2 mL of the benzathine penicillin G solution. Therefore, the correct answer is 2 mL. This calculation ensures that the patient receives the appropriate amount of medication based on the order and the available concentration.