Question

Scopolamine is available as a 0.4mg/1ml vial. You are asked to prepare scopolamine 1000mcg/100ml NS drip. How many mls of scopolamine should be added to the 100ml bag of NS ?

Answer 1

Step-by-step explanation

Conversion of milligram, mg to microgram, mcg

Note: 1 mg = 1000 mcg

So 0.4 mg scopolamine in 1 ml vial will be

`\frac{0.4mg*1000\text{mcg}}{1mg}=400\text{mcg}`

Note also that 0.01 mcg is equaivalent to 1.0 x10⁻⁵ mL.

This implies

`\begin{gathered} 0.01mcg=1.0*10^(-5)mL \\ 1000\text{mcg}=xmL\text{ scopolamine} \\ \\ \text{xmL scopolamine }=(1000mcg*1.0*10^(-5)mL)/(0.01mcg)=(0.01mL)/(0.01)=1ml \end{gathered}`

Therefore 1 mL of scopolamine should be added to the 100 mL of NS