Introduction to Oral Medications
Vocabulary
t.i.d – Three times a day
b.i.d – Twice a day
PO – By mouth
IM – Inject the medicine into the muscle
stat – Immediately
prn – Latin for “pro re nata” and means depending on the pain
Oral Medication Conversions
Understanding how to calculate oral medications is essential for nurses. To accomplish this task, dimensional analysis (unit matching) is the preferred method.
Oral medications come as solid tablets; capsules; chewable tablets or orally disintegrating tablets to be swallowed whole or sucked; or as a liquid in the form of drops, syrups, or solutions. In most cases, the ingredients in oral medication don’t enter the bloodstream until they reach the stomach or bowel.
1. Dimensional Analysis Review
Rule 1. Set up the problem. What units will your answer have?
[latex]\frac{unit}{1} -or- \frac{unit}{unit}[/latex]
Rule 2. Work the problem until the unit(s) on one side match the units on the other.
Rule 3. Do your units MATCH?
Rule 4. Solve by multiplying all the top numbers and write the answer in the numerator and then multiply all the bottom numbers and write the answer in the denominator.
[latex]\dfrac{numerator}{denominator}[/latex] = Dive the top by the bottom
Rule 5. Write the number to four (4) decimals and then round and write your units appropriately.
2. Conversion Steps
Read the question carefully. Determine the desired units for the final answer. Begin with the end in mind. Then, review the question. Remember that to cancel unwanted units, one must be on top and the other on the bottom of a fraction.
Oral Medication Conversion Example
Order: Cefaclor 250 mg PO t.i.d
Available: Cefaclor oral suspension labeled 125 mg per 5 mL
Solve: How many mL per dose?
mL → [latex]\frac{5mL}{125mg}[/latex] x [latex]\frac{250mg}{1dose} = 10mL[/latex]
Notes: Per means to “divide,” and always check your answer for reasonableness.
Oral Medication Conversion Video Tutorial[1]
- WisTech Open. (2024, August 12). Nursing dosage calculations - Oral medications [Video]. YouTube. CC BY 4.0. https://www.youtube.com/watch?v=lVUi4NPbDFI ↵
Three times a day.
Two times per day.
By mouth.
Inject the medicine into the muscle.
Immediately.
Latin for "pro re nata" means depending on the pain.