Drip calculations

hi!

so i am having problems refreshing myself on how to calculate drip calculations...i thought that the normal formula for these type of calculations is ml/hr x 1hr/60min x gtts/ml= gtts/ml, but with these new problems i am getting confused...

this problem states that mr. smith is a 75kg man and is recieving nipride 100mg/250 cc at 12cc/hr. how many mcg/kg/min is he recieving? i understand that you first want to figure out the concentration of the drug by dividing100mg by 250cc to get the concentration of 0.4mg/ml and then to multiply that by 1000 since you are looking for mcg. but it's after this that i tend to get lost...does anyone have a simple or clear way of explaining the steps to take to figure the calculation out?

any help would be appreciated...i think i am just confusing myself!

thanks!!

i never use formulas when working these kind of problems and always use dimensional analysis (factor label method) in order to make sure i get all the necessary terms and conversion factors into an equation. then, its merely a matter of canceling out the matching labels in the numerators and denominators, keeping the two labels i want in the numerator and denominator for the final answer and then using a calculator to compute the arithmetic. conversion factors are needed to get to the answer being asked for and i have highlighted them in red so you can see where they are coming from. notice that all the other labels on the number terms in the equation factor (or cancel) out.