**D = Desired Dose**

**Q = Quantity of Solution**

**H = Strength on Hand**

**X = Unknown quantity of Drug**

###### Sample:

- Physician orders 500 mg of ibuprofen (desired Dose) for a patient and you have 250 mg (Quantity on Hand) tablets (Quantity of solution) on hand.
*Solution:*D ÷ H x Q = X 500mg ÷ 250 mg x 1 tablet = 2 tablets Answer: 2 tablets.

###### Sample:

- Physician orders 1500 mg of liquid ibuprofen for a patient. Quantity of Ibuprofen is 500 mg in 1 cc, how much will you administer?
*Solution:*1500 mg ÷ 500 mg x 1cc = 3 cc Answer: 3 cc

##### Dosage and Conversions

###### Sample:

- MD orders 300 mg of Ibuprophen to be taken by a 6 kg infant every 4 hours. Label shows 75 – 150 mg/kg per day. Is the physician’s order within normal range?
*Solution:*6 x 75 = 450 mg (minimum dosage per day); 150 X6 = 900 (maximum dosage per day) 24 ÷ 4 = 6 dosages : 300 x 6 = 1800*Answer:*Dosage is not within range

##### IV Calculations

[amount of fluid to be infused] x [drop factor] ÷ minutes to infuse = gtts/min

*Sample:*

- Dr. A. orders your patient to receive 125 ml of D5W an hour for the next 8 hours. The nursing unit uses tubing with a drop factor of 10. What is the drip rate per minute?
*Solution:*Convert 1 hour to 60 minutes: 1250 x 10 gtts ÷ 60 minutes = 20.83 or 21 gtts/min*Answer:*21 gtts/min

###### Sample:

- Dr. B. orders a liter of D5W to run this 8-hour shift. The drop factor is 15. What is the drip rate per minute?
*Solution:*1 liter = 1000 cc of solution, next convert 8 hours to minutes (8 X 60 minutes) = 480 minutes 1000 cc x 15 gtts ÷ 480 minutes = 31.25 or 31 gtts/min*Answer:*31 gtts/min

###### Sample:

- Your patient weighs 200 lb and the order is to infuse 250 mg dobutamine in 500 ml NS at 10 mcg/kg/min. How many milligrams of dobutamine will infuse per hour?
*Solution:*200÷2.2= 90.90kg: 60 minutes = 1 hour: 10 mcg x 90.90kg x 60 min=5454.54 mcg/hour ÷ 1000 = 54.54mg/hr or 54.5mg/hr*Answer:*54.5mg/hr

##### The “7 Rights” of Medication Administration

- Right Patient
- Right Drug
- Right Dose
- Right Route
- Right Time
- Right Documentation
- Right to Refuse

##### Conversion Table

- 1 kilogram (kg) = 1000 grams (g)
- 1 gram (g) = 1000 milligrams (mg)
- Convert Grams to Milligrams by Multiplying grams by 1,000
- Convert Milligrams to grams by dividing milligrams by 1,000

- 1 milligram (mg) = 1000 micrograms (mcg)
- Grains (gr.) 15 = 1 Gram (g) or 1000 milligrams (mg)
- To convert g. to gr multiply by 15
- To convert gr to g divide by 15.

- 1 Grain (gr.) = 60 Milligrams (mg)
- To convert gr. to mg multiply gr. by 60
- To convert mg to gr. divide mg. by 60

- 1ml = 1 cc
- 1 ounce = 30 ml
- 1 tablespoon (T or tbsp) = 15 ml
- 1 teaspoon (t or tsp) = 5 ml
- 2.2 lb = 1 kg
- To convert pounds to kg divide pounds by 2.2
- To convert kg to pounds multiply by 2.2

*Reference : http://publichealth.lacounty.gov/*