NU141- Chapter 5 Dosage Calculations
A client is being treated for congestive heart failure (CHF) and is to receive 0.5 milligrams of digoxin, which is available in 250-microgram tablets. The nurse would correctly administer how many tablets?
2 tablets
An adult client with renal cancer, weighing 95 kg, is to receive vincristine 25 mcg/kg/day IV. What is the dosage of vincristine that the client is to receive daily?
2,375 mcg
The nurse determines that a newborn weighs 6 lb 7 oz. What would be the equivalent of this weight in grams?
2,920 g
A child weighs 11 kilograms. The health care provider orders a drug as follows: 0.2 mg/kg intravenously. What dose should the nurse administer?
2.2
A child weighs 22 kilograms. The physician orders a drug as follows: "1.1 mg/kg by intramuscular injection." The nurse determines the proper dose as:
24 mg
Methocarbamol (Robaxin) 1.5 g orally four times a day has been prescribed for a client to treat neck pain. Robaxin is available in 500-mg tablets. How many tablets will the nurse administer for each dose?
3
The nurse is converting grams to milligrams. How would the nurse move the decimal point?
3 places to the right
An older adult client states that he takes 5 grains of aspirin every day. The nurse would determine that the client takes how many milligrams every day?
300 mg
A group of students are practicing pediatric dosage calculation using Clark's rule. Which information would the students need?
Child's weight in pounds
The nurse is administering a drug metabolized in the liver to an infant. Because of the immaturity of the infant liver, what does the nurse determine should be done for dosing of this drug?
Ensure that lower drug dosages or an increased interval between doses is scheduled.
A public health nurse is preparing to administer an intramuscular injection of a vaccine to an 8-year-old girl. The nurse recognizes that the child is uncharacteristically quiet and appears tense. The nurse should recognize the possibility of what nursing diagnosis?
Fear related to IM injection
The clinical nurse educator who oversees the emergency department in a children's hospital has launched an awareness program aimed at reducing drug errors. What measure addresses the most common cause of incorrect doses in the care of infants and children?
Have nurses check their math calculations with a colleague before administering a drug.
Which best describes the manual redundancy system used to reduce potential error in medication administration by a nurse?
It is a process using the 5 rights and 3 checks.
Convert to units in the household system: a. 5 mL =_____ tsp b. 30 mL =_____ tbsp
a. 1 tsp b. 2 tbsp
Convert to units in the metric system: a. 150 gr =_____ g b. gr =_____ mg c. 45 min =_____ mL d. 2 qt =_____ L
a. 10 g b. 67 mg c. 3 mL d. 2 L
Convert the weights in the following problems: a. A patient weighs 170 lb. What is the patient's weight in kilograms? b. 200 lb =_____ kg c. A patient weighs 3,200 g. What is the patient's weight in pounds? d. 4,000 g =_____ lb
a. 77 kg b. 91 lb c. 7 lb d. 9 lb
Ratio and proportion
an equation in which a ratio containing two known equivalent amounts is on one side and a ratio containing the amount desired to convert and its unknown equivalent is on the other side
Heparin 800 units is ordered for a patient. The heparin is supplied in a multidose vial that is labeled 10,000 units/mL. How many milliliters of heparin would be needed to treat this patient? a. 0.8 mL b. 0.08 mL c. 8 mL d. 0.4 mL
b. 0.08 mL
An order is written for 1,000 mL of normal saline to be administered IV over 10 hours. The drop factor on the IV tubing states 15 drops/mL. What is the IV flow rate? a. 50 mL/h at 50 drops/min b. 100 mL/h at 25 drops/min c. 100 mL/h at 100 drops/min d. 100 mL/h at 15 drops/min
b. 100 mL/h at 25 drops/min
A patient needs to take 0.75 g of tetracycline PO. The drug comes in 250-mg tablets. How many tablets should the patient take? a. 2 tablets b. 3 tablets c. 4 tablets d. 30 tablets
b. 3 tablets
The average adult dose of meperidine is 75 mg. What dose would be appropriate for a 10-month-old infant? a. 50 mg b. 5 mg c. 25 mg d. 0.5 mg
b. 5 mg
A 2-year-old client is diagnosed with stomach flu and is suffering from vomiting and diarrhea. What is the most important factor in determining the correct dosage for his infection?
body surface area
A dose of 0.125 mg of digoxin was ordered for a patient who has been having trouble swallowing. The bottle of digoxin elixir reads 0.05 mg/mL. How much would you give? a. 5 mL b. 0.5 mL c. 2.5 mL d. 2 mL
c. 2.5 mL
The usual adult dose of diphenhydramine (Benadryl) is 50 mg. What would be the safe dose for a child weighing 27 lb? a. 0.9 mg b. 1.8 mg c. 9 mg d. 18 mg
c. 9mg
Aminophylline is supplied in a 500 mg/2.5 mL solution. How much would be given if an order were written for 100 mg of aminophylline IV? a. 5 mL b. 1.5 mL c. 2.5 mL d. 0.5 mL
d. 0.5 mL
An order is written for 700 mg of ampicillin PO. The drug is supplied in liquid form as 1 g/3.5 mL. How much of the liquid should be given? a. 5.25 mL b. 2.55 mL c. 6.25 mL d. 2.45 mL
d. 2.45 mL
Coversion
finding the equivalent values between two systems of measure
A nurse should recognize what as a metric system unit? (Select all that apply.)
gram milliliter kilogram
An infant's antiseizure medication has been prescribed after careful consideration of the unique pharmacokinetics among this population. What characteristic of neonates has the greatest bearing on drug metabolism?
immaturity of the infant's liver
A neonate's highly immature liver and resulting low levels of the enzyme cytochrome P-450 (CYP450) affects what aspect of pharmacokinetics?
metabolism
The nursing student is studying drug dosage and has learned that there are three systems of measurement associated with drug dosing. What are these systems? (Select all that apply.)
metric system apothecary system household measurement system
A nurse in a nutrition clinic is to give 2 cups of organic prune juice to a client every night. The nurse is to document this on the nursing chart. What unit will the nurse use to document the amount of juice according to the metric system of measurement?
milliliter
The nurse is administering regular insulin (Novolog) using a weight-based protocol. The nurse administers the insulin by using calculations performed by the:
nurse with verification by a second nurse.
Metric system
the most widely used system of measure, based on the decimal system; all units in the system are determined as multiples of 10
The nurse is ordered to administer 1.5 L of saline for a dehydrated client via an IV line. What is the equivalent of this amount of saline in milliliters?
1,500 mL
Order: 400 mg. Cefazolin I.V. Available: Cefazolin 500 mg powder to be diluted with 5 mL of sterile saline How many mL will the nurse administer?
4
The nurse, when using the method of dispensing drugs in which each tablet or capsule is packaged separately. Which dispensing method is this?
unit-dose method
When the nurse uses ratio and proportion to complete drug calculations, which formula would have the most potential for error?
1 mg.: 1,0000 mcg = X mg: 0.620 mcg
The nursing student is learning about the metric system and how it is the most commonly used system of measurement in medicine. The student demonstrates an understanding of the metric system when stating which?
"In the metric system, the liter is a unit of volume."
A young mother asks the nurse why she cannot give her 2-year-old child an adult dose of acetaminophen. The nurse explains why this is unsafe. What statement would indicate that the mother needs further education?
"My baby's dose of acetaminophen is based on a healthy adult male."
The nurse is conducting client education for a newly diagnosed diabetic. The order is for 32 units of insulin. The insulin is supplied in a multidose vial that is labeled 100 units/mL. How many mL of insulin would be needed to treat this client?
0.32
A client has been prescribed a one-time dose of 4 mg morphine IV. The medication is available in ampules of 10 mg/mL. What volume of morphine should the nurse draw up?
0.4
A client is prescribed a 12.5-mg dose of metoprolol for the treatment of high blood pressure. The nurse should administer how many 25-mg tablets?
0.5
A client has been prescribed 15 mL of an oral liquid potassium supplement. The nurse should administer how many ounces?
0.5 oz
Ordered: 0.35 mg. Available: 1.2 mg/2 mL. Proper dose: _____ mL.
0.58 (0.6) mL
A pediatric nurse is caring for a child who weighs 42 lbs. The health care provider has ordered methylprednisolone sodium succinate (Solu-Medrol), 0.03mg/kg/day IV in normal saline. How many milligrams should the nurse prepare to give?
0.6
Ordered: 6.5 mg. Available: 10 mg/mL. Proper dose: _____ mL.
0.65 mL
The health care provider has ordered 35 mg of Demerol IM for relief of a severe migraine headache. The package insert reads meperidine hydrochloride (Demerol) 50 mg/mL. How many milliliters would the nurse administer?
0.7
Medication doses given to children are usually smaller than those given to adults. Doses for children can also be calculated based on the child's weight. Which would be correct when calculating a dose based on weight?
1 kg equals 2.2 pounds
The nurse must use the metric system in dosage calculations. Which conversions are correct? (Select all that apply.)
1 kilogram = 1000 grams 1 gram = 1000 milligrams 1 milligram = 1000 micrograms
Ordered: 80 mg. Available: 50 mg/mL. Proper dose: _____ mL.
1.6 mL
A nurse is to administer 175 mg of a medication intramuscularly. The label on the multidose vial states that the concentration is 100 mg/mL. What volume of the drug should the nurse administer? (Record your answer using two decimal places.)
1.75
Ordered: 150,000 units. Available: 400,000 units/5 mL. Proper dose: _____ mL.
1.9 mL
The primary care provider orders cimetadine 100 mg P.O. daily. The medication is available as cimetadine 200 mg tablets. How much will the nurse give?
1/2 tablet
A pediatric client is admitted to the hospital. The nurse weighs the client and expresses the weight as:
10.1 kilograms.
A postoperative order is written for 15 gr of codeine every 4 hours as needed (pro re nata, p.r.n.) for pain. Each dose given will contain how many milligrams of codeine? _____ mg
1000 mg
Robitussin cough syrup 225 mg PO is ordered. The bottle reads 600 mg in 1 oz. How much cough syrup should be given? _____ mL
11.25 mL
A child with a urinary tract infection who is prescribed cephalexin 25 mg/kg/day in 3 divided doses. Knowing that the child weighs 15 kilograms, the nurse should administer how many mg with each dose?
125
Delatsone (prednisone) has been prescribed to a client with sarcoidosis. The client is to take 20 mg/day for 1 week and then taper the dose. The medication is available in 10-mg tablets. If the client follows the drug regimen, how many tablets would be taken in the first week?
14
A health care provider writes an order for a client to receive 500 mL of normal IV over 8 hours. If the IV infusion set delivers 15 drops per mL, how many drops per minute should the client receive?
15 drops/minute
A health care provider orders 500 mL D5W to be administered over 4 hours along with 80 mg gentamicin in 50 cc normal saline to be administered over 30 minutes. How many mL of fluid will the client receive in one hour (60 minutes)?
175 mL
The health care provider prescribes ascorbic acid 0.5 g daily. The drug label reads ascorbic acid 250 mg/tablet. The nurse would administer how many tablets?
2
The nurse is to administer 200 mg of trimethoprim and sulfamethoxazole suspension. The suspension must be shaken well as suspensions settle to the bottom of the bottle. The medication available is trimethoprim and sulfamethoxazole 250 mg in 5 mL. Which is the correct dosage required for administration?
4 mL
An 80-year-old with internal bleeding is admitted through the emergency room after a motor vehicle accident. The health care provider has ordered 2 units of packed red blood cells (1 unit is 250 mL) to infuse over 1 hour each. The drip rate on the blood administration set is10 gtt/mL. What would be the flow rate in drops per minute?
42
The nurse is preparing medication for a 30-month-old with right otitis media. The child weighs 33 pounds. The health care provider has ordered cephalexin, 50 mg/kg/day in divided doses every 8 hours. The medication concentration is 250mg/5mL. How many milliliters should the nurse give the toddler?
5
A client with an acute myocardial infarction is admitted to the coronary care unit. The health care provider has ordered Heparin 25,000 units in 250 mL normal saline to infuse at a rate of 600 units/hour. The nurse should set the infusion pump to deliver how many milliliters in an hour?
6
The nurse is to administer an off-label medication to a premature infant. To check for an appropriate dose for this client, the nurse refers to
A pediatric drug reference
A 2-year-old has been prescribed an antibiotic as part of treatment. What should the nurse consider to minimize the adverse effects?
Altering the dosage of the drug according to the child's age
A nurse is reading an article that uses minims as the measurement. The nurse identifies this as belonging to which system of measurement?
Apothecary
A nurse is using the metric system for solid measure. Which unit would the nurse expect to use?
Gram
Young rule
a method for determining pediatric drug dose based on the child's age and the usual adult dose; it states
Fried rule
a method of determining a pediatric drug dose for a child younger than 2 years of age, based on the child's age and the usual adult dose (assumes that an adult dose would be appropriate for a 12.5-year-old child); it states
Clark rule
a method of determining the correct drug dose for a child based on the known adult dose (assumes that the adult dose is based on a 150-lb person); it states
Apothecary system
a very old system of measure that was specifically developed for use by apothecaries or pharmacists; it uses the minim as the basic unit of liquid measure and the grain as the basic unit of solid measure
Change to equivalents within the system: a. 100 mg =_____ g b. 1,500 g =_____ kg c. 0.1 L =_____ mL d. 500 mL =_____ L
a. 0.1 g b. 1.5 kg c. 100 mL d. 0.5 L
