# Math formula for medication orders

by L
(E. Hampton)

Took a test today and I completely forgot how to do the formulas for medication orders. (ex. Rx orders Tylenol/ per kilogram, etc.) I panicked on the formula can you help?

### Comments for Math formula for medication orders

 Kilograms by: Anonymous You have to divide the amount in pounds by 2.2 and that is the Weight in kilograms. based on that you found the dose.

 IV infusion time and rate by: Anonymous I'm a pharmacy tech student, please help me understand how to calculate the following formula: At 1600 hours an IV of 1200 mL D5W at 27gtt/min. The infusion set used is calibrated for a drop factor of 15gtt/mL. What is the infusion time:______h?

 IV infusion time problem by: Brad Wojcik, Pharm D All you are doing in the problem is changing the units of mL into hours. The units of your answer will be in hours and the given is 1200 mL. The tools you will use to change mL into hours are the ratios, which always equal 1. There is a lot of extra info in this problem which you don't need. The ratios you need are 27 gtt/min and 15 gtt/mL. You also have to supply your own ratio of 60 min/h. We are going to multiply by 1200 mL by 3 different forms of 1 to change the units of mL into our desired units of h.1200 mL (15 gtt/mL)(1 min/27 gtt)(1 h/60 min) = 11.1 h (round to 11 h). And yes, for this problem 1 min/27 gtt does equal 1. Remember that all the ratios can be flipped upside down if needed.

 math by: Johnson Meloottu The info you need is here is three things. 1200 ml, 27gtt/min and 15gtt. Calculate how many gtt/ hour first. That is 27(60)=1620. Then 1620/15 = 108ml/hour. when you divide 1200ml/108ml you get the answer 11hours 11 minutes.