Drug Calculation Questions with Answers – Part 1
1) 700mL of saline solution is to be given over 8 hours. The IV set delivers 20d/mL. What is the required drip rate?
Answer
To calculate the required drip rate, we need to determine how many drops per minute (dpm) are needed to deliver 700 mL of saline solution over 8 hours.
- Calculate the total infusion time in minutes:
– 8 hours * 60 minutes/hour = 480 minutes
- Calculate the drip rate:
– Total volume to be infused: 700 mL
– IV set delivers: 20 drops/mL
– Drip rate (dpm) = (Total volume in mL * Drop factor) / Total time in minutes
– Drip rate (dpm) = (700 mL * 20 drops/mL) / 480 minutes
– Drip rate (dpm) = 14000 drops / 480 minutes
– Drip rate (dpm) ≈ 29.17 drops per minute
So, the required drip rate is approximately 29 drops per minute.
2) A pt is prescribed phenobarbitone 140mg.Stock ampoules contain 200mg/mL. What vol must be withdrawn for injection?
Answer
To determine the volume of phenobarbitone solution to be withdrawn for injection, we need to calculate the amount based on the concentration provided.
- Determine the concentration:
– The stock ampoules contain 200 mg of phenobarbitone per 1 mL.
- Calculate the volume needed for 140 mg:
– 200 mg is in 1 mL.
– To find out how many mL are needed for 140 mg, we use the ratio:
200 mg/ 1 mL = 140mg/ x mL
X = (140 mg * 1 mL)/ 200 mg = 0.7 mL
So, the volume to be withdrawn for injection is 0.7 mL.
3) A patient is to be given co-amoxiclav. The recommended dosage is 120mg/kg/day,3 doses per day, calculate the size of a single dose if the patient’s weight is 24kg
Answer
To calculate the size of a single dose of co-amoxiclav for a patient weighing 24 kg, we need to follow these steps:
- Determine the total daily dosage:
– Recommended dosage: 120 mg/kg/day
– Patient’s weight: 24 kg
– Total daily dosage: 120 mg/kg/day * 24 kg = 2880 mg/day
- Calculate the size of a single dose:
– The total daily dosage is divided into 3 doses per day.
– Size of a single dose: 2880 mg/day ÷ 3 doses/day = 960 mg/dose
So, the size of a single dose for the patient is 960 mg.
4) Doctors order: Demerol 50mg IVpq 6hr prn pain. Available ) Demerol 75mg/1.3ml. How many mL will you administer?
Answer
To determine the volume of Demerol (meperidine) to be administered, we need to calculate the amount based on the concentration provided.
- Determine the concentration:
– The available Demerol is 75 mg per 1.3 mL.
- Calculate the volume needed for 50 mg:
– 75 mg is in 1.3 mL.
– To find out how many mL are needed for 50 mg, we use the ratio:
75mg/1.3 mL = 50mg/ x mL
Solving for x:
x = 50mg * 1.3mL/ 75 mg = 0.867 mL
So, the volume to be administered is approximately 0.87 mL.
5) Doctors order: infuse 50mg of Amphotericin b in 250mL NS over 4hrs 15mins; Drip factor: 12gtt/mL. What flow rate (mL/hr) will you set on the IV infusion pump?
Answer
To calculate the flow rate for the IV infusion pump, we need to determine the volume to be infused per hour.
- Calculate the total infusion time in hours:
– 4 hours 15 minutes = 4.25 hours
- Calculate the flow rate:
– Total volume to be infused: 250 mL
– Total time: 4.25 hours
– Flow rate (mL/hr) = Total volume (mL) / Total time (hours)
– Flow rate (mL/hr) = 250 mL / 4.25 hours
– Flow rate (mL/hr) ≈ 58.82 mL/hr
So, the flow rate to be set on the IV infusion pump is approximately 59 mL/hr.
6) Doctors order: Tylenol supp 1gprqq 6hr prn temp>101: available: Tylenol supp352mg (scored). How many supp will you administer
Answer
To determine how many Tylenol suppositories to administer, we need to calculate the total dosage required and then figure out how many suppositories are needed to meet that dosage.
- Determine the total dosage required:
– The doctor’s order is for 1 gram (1000 mg) of Tylenol.
- Determine the dosage per suppository:
– Each Tylenol suppository contains 352 mg.
- Calculate the number of suppositories needed:
– Total dosage required: 1000 mg
– Dosage per suppository: 352 mg
– Number of suppositories needed: 1000mg/ 352mg/supp = approx 2.84
Since you can’t administer a fraction of a suppository, you would need to round up to the nearest whole number. Therefore, you would administer 3 suppositories to meet the required dosage.
7) One liter of Hartman’s solution is to be given 12hrs, calculate the flow rate of a volumetric infusion pump.
Answer
To calculate the flow rate for the volumetric infusion pump, we need to determine the volume to be infused per hour.
- Determine the total volume to be infused:
– Total volume: 1 litre (1000 mL)
- Calculate the total infusion time in hours:
– Total time: 12 hours
- Calculate the flow rate:
– Flow rate (mL/hr) = Total volume (mL) / Total time (hours)
– Flow rate (mL/hr) = 1000 mL / 12 hours
– Flow rate (mL/hr) ≈ 83.33 mL/hr
So, the flow rate to be set on the volumetric infusion pump is approximately 83 mL/hr.
8) A vial of amoxicillin 500mgs reconstituted with wifi to a given concentration of 200mg/mL.calculate the volume of the solution to be drawn up for injection if the preparation is for 120mg
Answer
To determine the volume of amoxicillin solution to be drawn up for injection, we need to calculate the amount based on the concentration provided.
- Determine the concentration:
– The reconstituted vial contains 200 mg of amoxicillin per 1 mL.
- Calculate the volume needed for 120 mg:
– 200 mg is in 1 mL.
– To find out how many mL are needed for 120 mg, we use the ratio:
200 mg/ 1 mL = 120 mg/ x mL
– Solving for x:
x = 120 mg* 1 mL/ 200 mg = 0.6 mL
So, the volume to be drawn up for injection is 0.6 mL.
9) 500mg of amoxicillin is prescribed to a patient three times a day, 250mg tablets are available. How many tablets for a single dose
Answer
To determine how many 250 mg tablets of amoxicillin are needed for a single 500 mg dose, we can follow these steps:
- Determine the dosage required:
– The prescribed dosage is 500 mg.
- Determine the dosage per tablet:
– Each tablet contains 250 mg of amoxicillin.
- Calculate the number of tablets needed:
– Number of tablets needed =500 mg/ 250 mg/tablet = 2 tablets
So, for a single 500 mg dose, you would need to administer 2 tablets of 250 mg amoxicillin.
10) Doctors order)Nafcillin 500mg Po Po; Available) Nafcillin 1gm tab (scored). How many tabs will you administer per day
Answer
To determine how many tablets of Nafcillin to administer per day, we need to calculate the dosage based on the available tablet strength.
- Determine the prescribed dosage:
– The doctor’s order is for 500 mg of Nafcillin.
- Determine the dosage per tablet:
– Each tablet contains 1 gram (1000 mg) of Nafcillin and is scored, meaning it can be split into two equal halves of 500 mg each.
- Calculate the number of tablets needed per dose:
– Since each tablet can be split into two 500 mg halves, you would administer half a tablet (500 mg) per dose.
- Calculate the total number of tablets needed per day:
– If the prescription is for 500 mg per dose and the dosing frequency is not specified, we assume it’s a single dose per day.
– Therefore, you would administer half a tablet (500 mg) per day.
So, you would administer half a tablet of Nafcillin per day.
11) A patient has been prescribed 1g Carbocisteine solution What volume should be administered? Please use the correct unit The bottle is 200mg/5ml
Answer
To determine the volume of Carbocisteine solution to be administered, we need to calculate the amount based on the concentration provided.
- Determine the concentration:
- The bottle contains 200 mg of cartocastein per 5 mL.
- Calculate the volume needed for 1 g (1000 mg):
- 200 mg is in 5 mL.
- To find out how many mL are needed for 1000 mg, we use the ratio:
200 mg/5 ml = 1000 mg/ xml
Solving for x:
X = (1000mg x 5ml)/ 200 mg = 25 mL
So, the volume to be administered is 25 mL.
12) A patient is prescribed 500mL of glucose 5% and sodium chloride 0.9% to be infused at 62.5mL per hour. What volume of fluid (in mL) would remain after 4 hours?
Give your answer as a whole number
Answer
Calculate the total volume infused in 4 hours:
Infusion rate: 62.5 mL per hour
Time: 4 hours
Total volume infused: 62.5 mL/hour * 4 hours = 250 mL
Subtract the infused volume from the initial volume:
Initial volume: 500 mL
Volume infused: 250 mL
Volume remaining: 500 mL – 250 mL = 250 mL
So, after 4 hours, 250 mL of fluid would remain.
13) A patient is prescribed 1L of Hartman’s solution to run over 10hrs, using an intravenous infusion set that delivers 20 drops per mL, how many drops per minute would you need to set the infusion at?
Answer
- Convert hours to minutes:
10 hours * 60 minutes/hour = 600 minutes
- Calculate the total volume in milliliters:
1 liter = 1000 milliliters
- Calculate the total number of drops:
1000 milliliters * 20 drops/milliliter = 20,000 drops
- Calculate the drip rate:
20,000 drops / 600 minutes = 33.33 drops per minute
Therefore, the infusion should be set at approximately 33 drops per minute.
14) Doctors order: Tazidine 0.3g/m tid. Reconstitution instructions: for 1m solution,add 1.5mL of diluent. Shake to dissolve, provides an approximate volume of 1.8mL (280mg/mL). How many mL will you give
Answer
Determine the total daily dose:
The doctor’s order is for 0.3g/m tid, which means three times a day.
Convert grams to milligrams:
1 gram is equal to 1000 milligrams, so 0.3g is equal to 0.3 * 1000 = 300mg.
Calculate the volume to administer:
The concentration of the reconstituted solution is 280mg/mL.
To administer 300mg, you would need 300mg / 280mg/mL = 1.07mL.
Therefore, you would administer approximately 1.07mL of Tazidine for a single dose.
A patient has been prescribed 2L of 0.9% sodium chloride
What is the volume in mL
liter (L) is equal to 1000 milliliters (mL).
Therefore, 2 liters (L) is equal to 2 * 1000 = 2000 milliliters (mL).
So, the volume in mL is 2000.