Video Library
Dosage calculations RN adult medical surgical assessment 3.1
Total Questions : 35
Showing 25 questions, Sign in for moreA nurse is preparing to administer heparin 7,500 units subcutaneous. Available is heparin 10,000 units/mL. How many ml. should the nurse administer? (Round the answer to the nearest hundredth. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To calculate the volume of heparin (in milliliters) to administer, you can use the following formula:
Volume (mL) = Desired dose (units) / Concentration (units/mL)
In this case, the desired dose is 7,500 units, and the concentration is 10,000 units/mL.
Volume (mL) = 7,500 units / 10,000 units/mL
Volume (mL) = 0.75 mL
So, the nurse should administer 0.75 mL of heparin.
A nurse is preparing to administer metronidazole 7.5 mg/kg via intermittent IV bolus to a client who weighs 212 lb. Available is metronidazole 500 mg/100 mL. How many mL should the nurse administer? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To calculate the dose of metronidazole for a client who weighs 212 lb, the nurse needs to convert the weight to kilograms and multiply it by the prescribed dose of 7.5 mg/kg.
One kilogram is equal to 2.2 lb, so the client's weight in kilograms is 212/2.2 = 96.36 kg. The dose of metronidazole in milligrams is 96.36 x 7.5 = 722.7 mg.
The nurse needs to find out how many mL of the available solution contain this amount of metronidazole.
The available solution has a concentration of 500 mg/100 mL, so the nurse can use a proportion to solve for the volume: 500/100 = 722.7/x.
Cross-multiplying and solving for x gives x = 722.7 x 100 / 500 = 144.54 mL.
The nurse should round the answer to the nearest whole number, so the final answer is 145 mL.
The nurse should administer 145 mL of metronidazole via intermittent IV bolus to the client.
A nurse is preparing to administer megestrol 200 mg PO to a client. Available is megestrol oral suspension 40 mg/mL. How many ml should the nurse administer? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To calculate the volume of megestrol oral suspension (in milliliters, mL) that the nurse should administer, use the following formula:
Volume (mL) = Dose (mg) / Concentration (mg/mL)
In this case, the dose is 200 mg of megestrol, and the concentration of the oral suspension is 40 mg/mL.
Volume (mL) = 200 mg / 40 mg/mL
Volume (mL) = 5 mL
The nurse should administer 5 mL of megestrol oral suspension to the client.
A nurse is caring for a client who has a new prescription for sotalol 320 mg/day in two divided doses. The amount available is 80 mg tablets. How many tablets should the nurse administer with each dose? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To determine how many tablets of sotalol the nurse should administer with each dose, you can use the following calculation:
Total daily dose / Number of doses per day = Dose per administration
In this case, the total daily dose is 320 mg, and it's divided into two doses per day.
320 mg / 2 doses = 160 mg per administration
Now, you know that the nurse should administer 160 mg of sotalol with each dose. The available tablets are 80 mg each, so you can calculate how many tablets are needed:
Dose per administration / Tablet strength = Number of tablets
160 mg / 80 mg/tablet = 2 tablets
Therefore, the nurse should administer 2 tablets of sotalol with each dose.
A nurse is preparing to administer morphine 0.1 mg/kg IM to a client who weighs 99 lb. Available is morphine 2 mg/mL. How many ml. should the nurse administer? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To calculate the amount of morphine (in mL) the nurse should administer, follow these steps:
Step 1: Convert the client's weight from pounds to kilograms. 99 lb / 2.2 lb/kg ≈ 45 kg (rounded to the nearest whole number)
Step 2: Calculate the total dose based on the client's weight. 0.1 mg/kg * 45 kg = 4.5 mg
Step 3: Determine how many mL of the available morphine solution (2 mg/mL) are needed to achieve the prescribed dose. 4.5 mg ÷ 2 mg/mL = 2.25 mL
Rounded to the nearest tenth, the nurse should administer 2.3 mL of morphine.
A nurse is preparing to administer dextrose 5% in water 1,000 mL IV to infuse over 6 hr. The nurse should set the IV pump to deliver how many mL/hr? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To calculate the infusion rate in mL/hr for dextrose 5% in water 1,000 mL over 6 hours, you can use the following formula:
Infusion Rate (mL/hr) = Total Volume (mL) / Total Time (hr)
Infusion Rate = 1,000 mL / 6 hr ≈ 166.67 mL/hr
Rounded to the nearest whole number, the nurse should set the IV pump to deliver approximately 167 mL/hr.
A nurse is preparing to administer acetaminophen 650 mg PO to a client for pain. Available is acetaminophen liquid 160 mg/5 mL. How many ml should the nurse administer? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To calculate the amount of acetaminophen liquid to administer, you can use the following formula:
Amount (mL) = (Desired Dose in mg) / (Concentration in mg/mL)
Amount (mL) = 650 mg / (160 mg/5 mL) = 20.31 mL
Rounded to the nearest tenth, the nurse should administer approximately 20.3 mL of acetaminophen liquid.
A nurse is preparing to administer cefazolin 500 mg IM every 8 hr. Available is cefazolin 1 g vial. The package insert instructs adding sterile water 2.5 mL to yield cefazolin 330 mg/mL. How many mL should the nurse administer per dose? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
First, we need to calculate the amount of cefazolin 500 mg in milligrams per milliliter (mg/mL) using the information provided:
Cefazolin concentration after reconstitution = 330 mg/mL Amount of cefazolin needed per dose = 500 mg
Now we can calculate the volume (mL) required for the dose:
Volume (mL) = Amount of cefazolin needed per dose / Cefazolin concentration after reconstitution
Volume (mL) = 500 mg / 330 mg/mL ≈ 1.52 mL
Rounded to the nearest tenth, the nurse should administer approximately 1.5 mL of cefazolin per dose.
A nurse is preparing to administer exenatide 10 mcg subcutaneous. Available is exenatide 250 mcg/mL. How many ml. should the nurse administer? (Round the answer to the nearest hundredth. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To calculate the volume of exenatide to administer, you can use the following formula:
Volume (mL) = (Desired Dose in mcg) / (Concentration in mcg/mL)
In this case, the desired dose is 10 mcg, and the concentration is 250 mcg/mL. Plugging these values into the formula:
Volume (mL) = 10 mcg / 250 mcg/mL = 0.04 mL
Rounded to the nearest hundredth, the nurse should administer approximately 0.04 mL of exenatide.
A nurse is preparing to reconstitute amoxicillin/clavulanate potassium oral suspension for administration to a client who has a respiratory tract infection. According to the label, which of the following actions should the nurse take? (Refer to the medication label below.)
Directions for mixing
Tap bottle until all powder flows freely. Add approximately 2/3 of total water for reconstitution
Shake vigorously to wet powder. Add remaining water, again shake vigorously Dosage: See accompanying prescribing Information
Discard after 10 days.
125 mg/5 mL
AMOXICILLIN CLAVULANATE POTASSIUM FOR ORAL SUSPENSION
When reconstituted, each 5ml contains AMOXICILLIN 125 mg. as the trihydrate
CLAVULANIC
ACID, 31.25 mg.
as clavulanate potassium
75mL
(when reconstituted)
A nurse is preparing to administer calcitonin 8 units/kg IM to a client who weighs 130 lb. Available is calcitonin 200 units/ml. for injection. How many ml. should the nurse administer? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To calculate the amount of calcitonin the nurse should administer, follow these steps:
Calculate the client's weight in kilograms: Weight in kilograms = Weight in pounds / 2.2 Weight in kilograms = 130 lb / 2.2 = 59.09 kg (rounded to two decimal places)
Calculate the total units of calcitonin needed: Total units = Weight in kilograms × Dose per kilogram Total units = 59.09 kg × 8 units/kg = 472.72 units
Determine the volume (ml) to administer using the concentration of the available calcitonin: Volume (ml) = Total units needed / Concentration (units/ml) Volume (ml) = 472.72 units / 200 units/ml = 2.36 ml
Rounded to the nearest tenth of a milliliter, the nurse should administer 2.4 ml of calcitonin.
A nurse is preparing to administer lisinopril 2.5 mg PO to an older adult client. Available is lisinopril 5 mg tablets. How many tablets should the nurse administer? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To calculate how many tablets of lisinopril 5 mg the nurse should administer to achieve a 2.5 mg dose, divide the desired dose by the dose per tablet:
Number of tablets = Desired dose / Dose per tablet
Number of tablets = 2.5 mg / 5 mg/tablet
Number of tablets = 0.5 tablets
A nurse is preparing to administer gentamicin 5 mg/kg via intermittent IV bolus to a client who weighs 210 lb. The amount available is gentamicin 10 mg/mL. How many ml, should the nurse administer? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To calculate how many milliliters (ml) of gentamicin to administer, follow these steps:
Calculate the client's weight in kilograms: Weight in kilograms = Weight in pounds / 2.2
Weight in kilograms = 210 lb / 2.2 Weight in kilograms ≈ 95.45 kg
Determine the dose based on the weight: Dose = 5 mg/kg × Weight in kilograms Dose = 5 mg/kg × 95.45 kg Dose ≈ 477.25 mg
Check the concentration of the available gentamicin: Concentration = 10 mg/mL
Calculate the volume (ml) to administer: Volume (ml) = Dose (mg) / Concentration (mg/ml) Volume (ml) = 477.25 mg / 10 mg/ml Volume (ml) ≈ 47.73 ml
Rounded to the nearest whole number, the nurse should administer approximately 48 ml of gentamicin.
A nurse is preparing to administer 0.9% sodium chloride 1,200 ml. IV to infuse over 8 hr. The nurse should set the IV pump to deliver how many mL/hr? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To calculate the IV pump rate, you need to divide the total volume (1,200 ml) by the total infusion time (8 hours). Here's the calculation:
IV Pump Rate (ml/hr) = Total Volume (ml) / Total Infusion Time (hr)
IV Pump Rate (ml/hr) = 1,200 ml / 8 hr
IV Pump Rate (ml/hr) = 150 ml/hr
So, the nurse should set the IV pump to deliver 150 ml/hr.
A nurse is preparing to administer tobramycin 3 mg/kg/day IM in three divided doses to a client who weighs 85 kg. The amount available is tobramycin 40 mg/ml. How many mL should the nurse administer per dose? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To calculate the amount of tobramycin to administer per dose, you need to follow these steps:
Step 1: Calculate the total daily dose. Total Daily Dose (mg) = Weight (kg) x Dose (mg/kg/day)
Total Daily Dose (mg) = 85 kg x 3 mg/kg/day = 255 mg/day
Step 2: Calculate the dose per divided dose (three divided doses). Dose per Divided Dose (mg) = Total Daily Dose (mg) / Number of Divided Doses
Dose per Divided Dose (mg) = 255 mg / 3 doses = 85 mg/dose
Step 3: Convert the dose to mL using the concentration. Dose (mL) = Dose (mg) / Concentration (mg/mL)
Dose (mL) = 85 mg / 40 mg/mL ≈ 2.125 mL
Rounded to the nearest tenth, the nurse should administer 2.1 mL per dose.
A nurse is preparing to administer fentanyl 0.5 mcg/kg via IV bolus to a client who weighs 187 lb. Available is fentanyl 50 mcg/ml. How many mi should the nurse administer? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To calculate the amount of fentanyl to administer, you need to follow these steps:
Step 1: Convert the client's weight from pounds to kilograms. Weight in kg = Weight in lb / 2.2046 Weight in kg = 187 lb / 2.2046 ≈ 84.82 kg
Step 2: Calculate the total dose based on the client's weight. Total Dose (mcg) = Weight in kg x Dose per kg Total Dose (mcg) = 84.82 kg x 0.5 mcg/kg = 42.41 mcg
Step 3: Determine the volume (mL) needed based on the available concentration. Dose (mL) = Total Dose (mcg) / Concentration (mcg/mL) Dose (mL) = 42.41 mcg / 50 mcg/mL ≈ 0.8482 mL
Rounded to the nearest tenth of a milliliter, the nurse should administer 0.8 mL of fentanyl.
A nurse is preparing to administer promethazine 25 mg IM to a client. Available is promethazine 50 mg/ml. How many ml administer? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero)
Explanation
To calculate the volume (mL) needed to administer 25 mg of promethazine using a concentration of 50 mg/mL, you can use the following formula:
Volume (mL) = Dose (mg) / Concentration (mg/mL)
In this case, the dose is 25 mg, and the concentration is 50 mg/mL:
Volume (mL) = 25 mg / 50 mg/mL = 0.5 mL
So, the nurse should administer 0.5 mL of promethazine.
A nurse is preparing to administer amiodarone 300 mg IV bolus over 10 min to a client. Available is amiodarone 50 mg/mL. How many mL should the nurse administer? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To calculate the volume (mL) needed to administer 300 mg of amiodarone using a concentration of 50 mg/mL, you can use the following formula:
Volume (mL) = Dose (mg) / Concentration (mg/mL)
In this case, the dose is 300 mg, and the concentration is 50 mg/mL:
Volume (mL) = 300 mg / 50 mg/mL = 6 mL
So, the nurse should administer 6 mL of amiodarone.
A nurse is preparing to administer 0.9% sodium chloride 1,500 mL. IV to be infused over 12 hr. The nurse should set the IV pump to deliver how many ml/hr? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To calculate the infusion rate in mL/hr, you can use the following formula:
Infusion Rate (mL/hr) = Total Volume (mL) / Time (hr)
In this case, the total volume is 1,500 mL, and the time is 12 hours:
Infusion Rate (mL/hr) = 1,500 mL / 12 hr = 125 mL/hr
So, the nurse should set the IV pump to deliver 125 mL/hr.
A nurse is preparing to administer enoxaparin 40 mg subcutaneous for prevention of deep vein thrombosis. Available is enoxaparin 100 mg/ml. How many mL should the nurse administer? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To calculate the mL of enoxaparin to administer, you can use the following formula:
Volume (mL) = Dose (mg) / Concentration (mg/mL)
In this case, the dose is 40 mg, and the concentration is 100 mg/mL:
Volume (mL) = 40 mg / 100 mg/mL = 0.4 mL
So, the nurse should administer 0.4 mL of enoxaparin.
A nurse is preparing to administer phenobarbital 2 mg/kg/day IV divided in 2 equal doses to a client who weighs 165 lb. Available is phenobarbital 65 mg/mL. How many ml should the nurse administer per dose? (Round the answer to the nearest tenth. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To calculate the mL of phenobarbital to administer per dose, you can use the following steps:
Convert the client's weight from pounds to kilograms. There are approximately 2.2 pounds in 1 kilogram.
Weight in kg = 165 lb / 2.2 lb/kg ≈ 75 kg
Calculate the total daily dose based on the client's weight and the prescribed dose per kilogram:
Total daily dose = 2 mg/kg/day × 75 kg ≈ 150 mg/day
Since the dose is divided into two equal doses per day, calculate the dose per dose:
Dose per dose = Total daily dose / 2 = 150 mg / 2 = 75 mg
Now, you need to find out how many mL of phenobarbital 65 mg/mL corresponds to a dose of 75 mg:
Volume (mL) = Dose (mg) / Concentration (mg/mL) = 75 mg / 65 mg/mL ≈ 1.1538 mL
Rounded to the nearest tenth, the nurse should administer approximately 1.2 mL of phenobarbital per dose.
A nurse is caring for a client who reports taking 1 Tbsp of guaifenesin oral solution every 4 hr. The concentration on the client's bottle reads guaifenesin 100 mg/5 mL. How many mg of guaifenesin is the client taking with each dose? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To determine how many milligrams (mg) of guaifenesin the client is taking with each dose, you can use the following calculation:
Dose (mg) = (Volume in mL) x (Concentration in mg/mL)
The client is taking 1 tablespoon (which is approximately 15 mL) of guaifenesin oral solution, and the concentration is 100 mg/5 mL.
Dose (mg) = (15 mL) x (100 mg/5 mL) = 300 mg
So, the client is taking 300 mg of guaifenesin with each dose. Rounded to the nearest whole number, the answer is 300 mg.
A nurse is caring for a client who reports taking 1 Tbsp of guaifenesin oral solution every 4 hr. The concentration on the client's bottle reads guaifenesin 100 mg/5 mL. How many mg of guaifenesin is the client taking with each dose? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To calculate how many milligrams (mg) of guaifenesin the client is taking with each dose, you can use the following steps:
Determine the volume of the client's dose. The client is taking 1 tablespoon (Tbsp) of guaifenesin oral solution.
1 Tbsp is approximately equal to 15 mL.
Determine the concentration of guaifenesin in the oral solution, which is 100 mg/5 mL.
Calculate the amount of guaifenesin in the client's dose:
Amount (mg) = (Volume of dose in mL / Concentration in mg/mL)
Amount (mg) = (15 mL / 5 mg/mL) = 3 doses of 100 mg each
So, the client is taking 300 mg of guaifenesin with each dose.
A nurse is preparing to administer pyrazinamide 20 mg/kg PO to a client who weighs 165 lb and has tuberculosis. Available is pyrazinamide 500 mg tablets. How many tablets should the nurse administer? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To calculate how many tablets of pyrazinamide the nurse should administer, you can use the following steps:
Convert the client's weight from pounds (lb) to kilograms (kg):
Client's weight in kg = Client's weight in lb / 2.2 Client's weight in kg = 165 lb / 2.2 ≈ 75 kg
Determine the total dosage required based on the client's weight:
Total dosage = Client's weight in kg × Dosage (mg/kg) Total dosage = 75 kg × 20 mg/kg = 1500 mg
Determine the number of tablets needed:
Number of tablets = Total dosage / Tablet strength Number of tablets = 1500 mg / 500 mg/tablet = 3 tablets
The nurse should administer 3 tablets of pyrazinamide
A nurse is preparing to administer acetaminophen 15 mg/kg via intermittent IV bolus to a client who weighs 99 lb. The amount available is acetaminophen 1,000 mg/100 mL. How many mL should the nurse administer? (Round the answer to the nearest whole number. Use a leading zero if it applies. Do not use a trailing zero.)
Explanation
To calculate the mL of acetaminophen to administer, follow these steps:
Convert the client's weight from pounds (lb) to kilograms (kg):
Client's weight in kg = Client's weight in lb / 2.2 Client's weight in kg = 99 lb / 2.2 ≈ 45 kg
Determine the total dosage required based on the client's weight:
Total dosage = Client's weight in kg × Dosage (mg/kg) Total dosage = 45 kg × 15 mg/kg = 675 mg
Determine the mL to administer based on the available concentration:
Concentration (mg/mL) = 1,000 mg / 100 mL = 10 mg/mL
Calculate the mL to administer:
mL to administer = Total dosage (mg) / Concentration (mg/mL) mL to administer = 675 mg / 10 mg/mL = 67.5 mL
Round the answer to the nearest whole number:
The nurse should administer 68 mL of acetaminophen
Sign Up or Login to view all the 35 Questions on this Exam
Join over 100,000+ nursing students using Naxlex’s science-backend flashcards, practice tests and expert solutions to improve their grades and reach their goals.
Sign Up Now
