Child weighs 33 lbs The MD orders Mefoxin 80 mgKgday l M in

Child weighs 33 lbs. The MD orders Mefoxin 80 mg/Kg/day l M in 3 equal doses The pharmacy supplies Mefoxin 1 Gm vials with the instructions to add 10 NaCl to yield solution of 500 mg = 5 mL. Maximum safe dose is 1500 mg/day. wt. in Kg total dose/24 hrs. dosage/one dose volume lone dose it safe?

Solution

(a)

Weight of child = 33 lbs = 33*0.453 = 14.96 kgs

(b)

Dose ordered by the MD is 80 mg/kg per day

Since the child has weight 14.96 kgs, so total dose for the child per day = 80*14.96 = 1196.8 mg

(c)

Since the medicine is to be administered in 3 equal doses, so dosage per dose =

Total dosage / No. of doses = 1196.8 / 3 = 398.93 mg per dose

(d)

After the dilution with NaCl, the solution has conc. 500 mg / 5 mL, which is equal to 100 mg/mL

So volume required for one dose = 398.93 / 100 = 3.98 mL

(e)

The dose is safe because it is within the prescribed limits, i.e. , 1196.8 mg < 1500 mg on a per day basis.