Question

1. A patient weighing 60 kg has been prescribed Bactrim 250 mg IV 2 times a day.  The safe dose range for Bactrim is 8-10mg/kg/day.  The medication available is 80mg/5ml.  

a.        Is the prescribed dose therapeutic?  

b.       Is the prescribed dose safe?

c.        How many mL’s per dose should be administered? (Round to nearest tenth)

Answer 1

Patient weight= 60kg

Prescribed dose (D) =250 mg

Dose in hand ( H) = 80

Quantity it is in (Q) = 5 ml

Question no 1

Yes the dose given is therapeutic as the range of therapeutic dose of bactrim is 8-15 mg/ kg

Here the dose is 500 mg per day so it is in the therapeutic range

Question no 2

Prescribed dose = 250 mg 2 times that is 500mg

The safe dose is

Minimal safe dose = 8× 60= 480 mg

Maximal safe dose= 10× 60 = 600mg

So safe dose is 480-600mg

As 500 comes in between it is safe

Question no 3

Patient weight= 60kg

Prescribed dose (D) =250 mg

Dose in hand ( H) = 80

Quantity it is in (Q) = 5 m

Amount to be administered per dose =recommended dose.× volume it is in / dose in hand

A= D/ H× Q

substituting value

A= 250×5/80. = 15.625 ml

Approximately 16 ml give in single dose