dosage calculations

Question

the recommended dose for streptomycin is 8 to 20mg/pound/day. A person weighing 94 pounds is to receive 2mL injected every 6 hours. Medication label reads, Streptomycin 1gram per 5mL. Is the injection ordered within the recommended dosage? How many mg will the patient receive per day?

Answer 1

The stock concentration is 1g/5mL or 1000mg/5mL = 200 mg/mL

At 2 mL every 6 hours, they patient receives the injection 4 times/day.

So in total, the patient is receiving:

200 mg/mL * 2mL * 4/day = 1600 mg/day

 

At their weight, the recommended dose range is from: 

8 mg/lb/day * 94 lbs = 752 mg/day

to

20 mg/lb/day * 94lbs = 1880 mg/day

 

So 1600 mg/day falls within the recommended dosage range of 752 mg/day - 1800 mg/day