Roman Numerals/Alligations
Convert 66 to Roman numerals
LXVI
furosemide 80mg tabs
Sig: 40mg qam x 1/12 refills x 3
How many tablets should be dispensed?
What is the authorized quantity?
15 tablets to dispense
60 tablets authorized quantity
Drug E 500mg
Sig: 250mg tid
m: xxvi
What is the dispense quantity?
What is the days supply?
26 tablets/1.5 tablets per day
17 days supply
Insulin
Sig: 19 units tid
M: 3 cartridges
What is the dispense quantity in milliliters (mL)?
What is the days supply?
so, 3 cartridges = 45 mls
4500 units/ 57 units/day = 78 days
Formula:
Drip rate = total volume(ml) x drip factor/total #minutes
A physician orders Zantac 50 mg to be infused in 0.2 L of normal saline (NS) over 15 minutes using a 15 gtts/mL drop factor. What is the drip rate in gtts/min?
Convert 0.2 L to mL = 0.2 x 1000 = 200 mL
Drip rate = 200 mL x 15 gtt/ml/ 15 minutes
= 200 minutes
What is the Roman Numeral that represents 109?
CIX
Using the most appropriate tablet strength, calculate the total quantity of prednisone required for this prescription. What is the days supply?
Prednisone
Sig: 45mg qd x10 days, 35mg qd x 3 days, 15mg qd x 3 days, 10mg qd x 3 days, 5mg qd x 30days
156 tablets
49 days
Ceftin
SIG: 20mg/kg/day q12h x 10/7
Patient weight: 55 lbs.
How many mL would you give for ONE dose?
What is the dispense quantity?
125 mg/5 mL = 250 mg/xmL = 10 mL
10 mL for ONE dose
10 mls x 2 x 10 days = 200 mL
dispense 2 bottles of 100 mL
How many tablets should be dispensed for the following prescription? What is the authorized quantity?
Tegretol 200mg tablets
Sig: 500mg tid x 2/12
Refill x 2
Dispense quantity = 450 tablets
Authorized Quantity = 1350 tablets
Clark's Rule:
Pediatric Dose = Childs weight(lbs) x Adult Dose divide by 150
Using Clark's Rule, calculate the recommended pediatric dose of Drug A.
Adult dose of Drug A = 250 mg
Child's weight = 18 kg
Convert 18 kg to lbs = 18kg x 2.2 = 39.6
39.6 x 250 mg / 150 = 66 mg
Convert CCCXCV to Arabic numbers?
395
Insulin R - 19 units tid
m: 1 vial
What is the dispense quantity in milliliters (mL) for this prescription?
What is the days supply?
10 mL
1000 units/ 57 units/day = 17.54
change to 17 days - round DOWN
Amoxil
Sig: 12mg/kg tid x 10/7
Patients weight: 20 kg
How many mL would you give for ONE dose?
What is the dispense quantity?
250 mg/5mL = 240 mg/xmL = 4.8 ml one dose
144 mL = 150 mL bottle x1
Biaxin 500mg tabs
Sig: 2g stat, 500mg bid x 14 days
What is the dispensed quantity?
What is the days supply?
32 tablets
14 days
Step 1: Look for "x__ days, THAT is your answer
ex. 500 mg bid x 14 days = 14 days supply
Step 2: stat/loading dose, day 1 dose , DO NOT affect days supply.
Step 3: if no duration is given, USE this FORMULA
days supply = total quantity/Dose per day
A physician orders 50 mEq of potassium chloride to be added to IV fluids. The medication label indicates a concentration of 2 mEq/mL. What volume of potassium chloride should be added to the IV fluids?
Volume(mL) = desired amount/ concentration
Volume(mL) = 50 mEq/mL/ 2 mEq/mL
Volume(mL) = 25 mL
The doctor orders 450 mL of a 15% potassium chloride solution. You have 20% and 5% potassium chloride solutions available. What volume of 20% potassium chloride solution is required to prepare the order?
Do not include units in your answer. Round your answer to the nearest hundredths.
This is a classic alligation problem
Target = 15% Available = 20% and 5%
Set it up: 20-15 = 5 and 15 -5 = 10
Ratio 10:5 = 2:1 = 3 parts
20% solution = 2/3 x 450 = 300
Insulin R - 10 units tid
m: 1 vials
What is the dispense quantity in milliliters (mL) for this prescription?
What is the days supply?
10 mL
1000 /30 = 33.33 days
Maximum 28 days per vial
Days supply is 28 days
Amoxil
Sig: 220mg tid x 10 days
How many mL would you give for ONE dose?
What is the dispense quantity?
250 mg/5 mL = 220 mg/xmL = 4.4 mL single dose
132 mL = 150 mL = 1 bottle
Given the following prescription:
Amoxicillin 500mg
Sig: 2g stat, 1 tid x 14/7
How many capsules should be dispensed?
What is the total prescription price for an MLP drug that costs $126.78 per 500 capsules. Use the following formula:
Total Price = 1.07 × (1.03 × MLP) + 12.15
What is the days supply?
Patients co-pay if they are fully covered through AISH
46 capsules dispensed
126.78/500 = x$/46 =$11.66
Total Price = 1.07 x (1.03 x 11.66) + 12.15
= 25.00
Days supply 14 days
Co-pay is $0.00 ( no charge for patient)
Prepare 500 mL of a 2.5% hydrogen peroxide solution from a 10% stock solution. How many milliliters of sterile water are required to dilute the hydrogen peroxide?
Do not include units in your answer. Round your answer to the nearest hundredth.
Use alligation (dilution chart) method
10% (stock), 2.5% (desired), 0% (diluent, water)
step 1: cross-subtract 10-2.5 = 7.5 parts (water)and 2.5-0 = 2.5 parts (this is stock)
step 2: ratio stock: water = 2.5:7.5
simplify 1:3
1+3 = 4 parts 1/4 x 500= 375 mL final answer
A prescriber orders 2 oz of a 40% Cream A, but the pharmacy only stocks 75% and 20% concentrations. How much of the 75% Cream A is required to prepare a 40% cream?
Round your answer to the nearest hundredths.
Use an alligation chart:
find the ratio- 75% - 40% = 35%/ 40% -20% = 20%
So ratio is 75%: 20% = 20:35 (55 parts) total
75% Cream A = 20/55 x 60 g = 21.82 g
Dimenhydrinate 1g/2mL (Pack size: 2mL multi-use vial)
Sig: Inject 350mg qam x 9/7
How many vials of dimenhydrinate would be required to fill this prescription?
How many mL(s) are injected for 1 dose?
Answer is 6.3 mls
You would need 4 vials of 2 mls vials
0.7 mL injected for 1 dose
Biaxin
SIG: 12mg/kg bid x 10/7
Patient weight: 34kg
How many mL would you give for ONE dose?
What is the dispense quantity?
12 mg x 34 kg = 408 mg
250 mg/5 mL = 408 mg/x mL = 8.2 ml single dose
8.2 mL x 2 x 10 = 164 mL
dispense 2 bottles of 105 mL = 210 mL
Given the following prescription: Lamisil Cream - bid ud mitte: iii oz How many grams should be dispensed?
What is the total prescription price for a base drug that costs $17.97 per 30 g? Use the following formula:
Total Price = 1.07 × (1.075 × base price) + 12.15
What is the days supply?
90 grams
Total prescription price = $74.16
10 days for topicals
A physician orders 260 ml of 15% dextrose in water. The stock solution is 50 % dextrose in 10 ml ampules. How many ampules of dextrose would be necessary to complete this order?
Desired = 15%
Stock = 50% Diluent (water) = 0%
50%: Water = 15:35 = 50 parts total
Volume of 50% = 15/50 x 260 mL = 78 mL
78/10 = 7.8 ampoules = 8 ampoules
*IF ampoules/vials are single-use, always round UP (never down)