# Prednisone Syrup Prescription

by Ebony

(Houston)

I think the answer for PTCB Practice Test 12 Question #4 may be incorrect. Here is the question:**A patient with ulcerative colitis has been ordered the following prescription:Rx: Prednisolone Syrup 0.30%Sig:15mg qd ac X7 days.What will the dosage instructions be on the patients packaging?A. Take 2 Teaspoons daily before a meal.B. Take 1 Tablespoon daily before a meal.C. Take 2 Tablespoons daily before a meal.D. Take 1 Teaspoon daily before a meal.**

The answer Says D, but 15 mg = 1 tablespoon and 1 tsp is 5 mg.

So the answer should be B... I believe? Correct me if I'm wrong. Thanks!

**Reply:**By Jerry

**Firstly, 1 tsp is MUCH more that 5 mg.**

Since you're probably familiar with sugar, let's use that for an example.

**1 tsp of sugar is over 4000mg.**The confusion starts when we learn to mix things using teaspoons and tablespoons in cooking recipes, because it's easier than weighting things like sugar while making cookies. Imagine if a cake recipe told you to add 250,000 mg of sugar. Adding 1 cup is lots easier, right?

So, the mistake you're making is common, and one that new pharm tech students often make when getting started with the math.

**You are confusing liquid and dry measurements.**

When doing pharmacy math - Always use volume measurements (mL, quart, Liquid ounce, Tablespoon, Teaspoon) for liquid and weight measurements (mg, Kg, Ounce, Lb) for solid and dry substances.

This question involves a concentration of a substance in a liquid, which is prepared as 0.3%. So, we know that there are 300mg in every 100mL.

So, we need to find out how many mL will contain 15mg. This is done most quickly with a proportions math equation like this:

300mg - - - - - - - - 15mg

-------- =

**0.3%**= ---------

100mL - - - - - - - - -

**X -**

When you do the math and solve for

**X**, you get

**5mL**, which is a

**1tsp**.

So, the answer is:

**D. Take 1 Teaspoon daily before a meal.**