Question

Order: Vancomycin 40 mg/kg/d divided into 4.6h. doses IV. The manufacturer recommends reconstituting 500 mg vial with 10 mL, yielding 50 mg/mL. How many milliliters will you administer for each dose if the client weighs 90 lb? a) 180 mL b) 18 mL c) 8.2 mL d) 3.4 mL

Answer 1

ANSWER.

* Calculation of volume(ml) of drug required.

       Formula

          Volume(ml) = Desired dose(D)/Dose in hand(H) * Quantity(Q).

    Here

          Ordered dose = 40 mg/kg/day.

          Patient weight = 90 lb

Convert lb to kg for calculation

            1 lb = 0.454 kg.

      Patient weight = 90 * 0.454

                              = 40.9 kg

        Desired dose (D) = 40 * 40.9

                                     = 1636 mg

         Dose in hand (H) = 50 mg.

                Quantity (Q) = 1 ml

As per above formula

       Volume(ml) of drug required = D/H * Q

                                                     = 1636/50 * 1

                                                     = 32.7 * 1

                                                     = 32.7 ml per day

      Volume of drug required per dose = 32.7 ml q6h

             q6h is 4 times a day.

       So

          Volume of drug required per dose = 32.7/4

                                                            C = 8.2 ml.