The order is clindamycin 300 mg IM. The single-use vial on hand reads 600 mg/4 mL (150 mg/mL). How many milliliters will be administered?

The order is clindamycin 300 mg IM. The single-use vial on hand reads 600 mg/4 mL (150 mg/mL). How many milliliters will be administered?

• A. 1 mL
• B. 0.5 mL
• C. 4 mL
• D. 2 mL

Answer: (D)

The key idea is to convert the vial's strength into milligrams per milliliter and then scale up to the required dose. The vial has 600 mg in 4 mL, which is 600 mg ÷ 4 mL = 150 mg per mL. To get 300 mg, you need 300 mg ÷ 150 mg/mL = 2 mL. Since 1 mL provides 150 mg, twice that amount gives 300 mg. So administer 2 mL.

The key idea is to convert the vial's strength into milligrams per milliliter and then scale up to the required dose. The vial has 600 mg in 4 mL, which is 600 mg ÷ 4 mL = 150 mg per mL. To get 300 mg, you need 300 mg ÷ 150 mg/mL = 2 mL. Since 1 mL provides 150 mg, twice that amount gives 300 mg. So administer 2 mL.