Weight Based Dosing
amoxicillin (Polymox):
A medication order states 20 mg/kg/dose of amoxicillin for a child weighing 18 kg. How many mg per dose?
(Round to the nearest tenth, if applicable. Use a leading zero, but no trailing zero, if applicable. Label your answer.)
20 mg x 18kg =
360 mg
A child weighs 40 lbs. The doctor orders ibuprofen for a fever. The safe dose range for this medication is 10–15 mg/kg. What is the maximum safe dose for this child?
(Round to the nearest tenth, if applicable. Use a leading zero but no trailing zero, if applicable. Label your answer.)
40 lbs / 2.2 = 18.2kg
18.2 kg x 15 mg =
273 mg
levothyroxine (Synthroid):
A provider orders 75 mcg of levothyroxine. The available strength is 25 mcg per tablet. How many tablets should the nurse administer?
(Round to nearest tenth, if applicable. Use leading zero but no trailing zero, if applicable. Label your answer.)
(75 mcg / 25 mcg) * 1 tablet =
3 tablets
diphenhydramine (Benadryl): A doctor prescribes 50 mg of diphenhydramine. The liquid form available is 12.5 mg per 5 mL. How many mL should be given?
(Round to the nearest tenth, if applicable. Use leading zero but no trailing zero, if applicable. Label your answer.)
(50 mg / 12.5 mg) x 5 mL =
20 mL
A patient's weight is 180 lbs. What will the weight be in kg?
(Round to the nearest tenth. Use a leading zero but no trailing zero, if applicable. Label your answer.)
180 lbs / 2.2 =
81.8 kg
metoprolol (Toprol XL):
A provider prescribes 0.5 mg/kg of metoprolol for an adult weighing 70 kg. How many mg should be administered?
(Round to the nearest tenth, if applicable. Use a leading zero but no trailing zero, if applicable. Label your answer.)
0.5 mg x 70 kg =
35 mg
ondansetron (Zofran):
A doctor orders 2 mg of ondansetron for a child who weighs 13.6 kg. The safe dosage of this medication is 0.15 mg/kg. Is this a safe dose?
(Round to the nearest whole number, if applicable. Use a leading zero but no trailing zero, if applicable. Label your answer.)
13.6 kg x 0.15mg = 2.04 mg
Rounded = 2mg
YES! Safe Dose!
clindamycin (Cleocin):
A doctor orders 900 mg of clindamycin. The available strength is 0.3 g per capsule. How many capsules should be given?
(Round to the nearest tenth, if applicable. Use leading zero but no trailing zero, if applicable. Label your answer.)
(900mg / 0.3g) x ( 1 / 1000) x 1 capsule =
3 capsules
meperidine (Demerol):
A provider orders 7 mg of meperidine. The available strength is a syringe with 400 mg / 40mL. How many mL will the patient receive?
(Round to the nearest tenth, if applicable. Use leading zero but no trailing zero, if applicable. Label your answer.)
(7 mg / 400 mg) x 40 mL =
0.7mL
A mother has called the nurse line stating she gave her child 1 teaspoon of acetaminophen.
How many mL did the mother give her child?
(Round to the nearest whole number, if applicable. Use leading zero but no trailing zero, if applicable. Label your answer.)
5 mL
ibuprofen pediatric (Children's Motrin):
A child weighs 55 lbs. For ibuprofen, the order is for 5 mg/kg/day. How many mg should the child receive daily?
(Round to the nearest tenth, if applicable. Use leading zero, but no trailing zero, if applicable. Label your answer.)
55 lbs / 2.2 = 25 kg
5 mg x 25 kg =
125mg daily
diphenhydramine (Benadryl):
A doctor orders diphenhydramine for a child who weighs 63 lbs. The safe dosage is 5-7 mg/kg/day. What is the safe daily dose range for this child?
(Round to the nearest tenth, if applicable. Use a leading zero but no trailing zero, if applicable. Label your answer.)
63 lbs / 2.2 = 28.6 kg
28.6 kg x 5 mg = 143 mg
28.6 kg x 7 mg = 200.2 mg
Low: 143 mg High: 200.2 mg
digoxin (Lanoxin):
A patient requires 0.125 mg of digoxin. The pharmacy provides 62.5 mcg per tablet. How many tablets should be given?
(Round to the nearest tenth, if applicable Use leading zero but no trailing zero, if applicable. Label your answer.)
(0.125 mg / 62.5 mcg) x (1000 / 1) x 1 =
2 tablets
clindamycin (Cleocin):
Order 275mg of clindamycin IV. Available: 5mg/mL concentration. How many mL of solution will you give?
(Round to the nearest tenth, if applicable. Use leading zero but no trailing zero, if applicable. Label your answer.)
(275 mg / 5 mg) x 1 mL =
55 mL
lactated ringers (LR):
Convert 3.5 L of lactated ringers solution to mL.
(Round to the nearest tenth, if applicable. Use a leading zero but no trailing zero, if applicable. Label your answer.)
3.5 L x 1000 =
3,500 mL
acetaminophen liquid (Children's Tylenol):
A pediatric patient weighing 24 kg is ordered 15 mg/kg/day of acetaminophen, divided into three doses. How many mg per dose?
(Round to the nearest tenth, if applicable. Use leading zero but no trailing zero, if applicable. Label your answer.)
24 kg x 15 mg = 360 mg per day
360 mg per day / 3 doses =
120 mg per dose
ampicillin (Principen):
A doctor orders 400 mg IV every 6 hours. The child weighs 28 lbs. The safe dosage range for ampicillin is 50–100 mg/kg/day. Is this a safe dose for this patient?
(Round to the nearest tenth, if applicable. Use a leading zero but no trailing zero, if applicable. Label your answer.)
28 lbs / 2.2 = 12.7 kg
12.7 kg x 50 mg = 635 mg (low)
12.7 kg x 100 mg = 1270 mg (high)
400 mg is NOT a safe dose - too low.
cephalexin (Keflex):
The doctor prescribes 0.5 g of cephalexin. Available: 250 mg per tablet. How many tablets should the patient take?
(Round to the nearest tenth, if applicable. Use a leading zero but no trailing zero, if applicable. Label your answer.)
(0.5 g / 250 mg) x (1000 / 1) x 1 tablet =
2 tablets
An adult patient is ordered 80 mg IV methylprednisolone sodium. The pharmacy has 100 mg / 2mL vials available. How many mL should the nurse administer?
(Round to the nearest tenth, if applicable. Use leading zero but no trailing zero, if applicable. Label your answer.)
(80 mg / 100 mg) x 2 mL =
1.6 mL
levothyroxine (Synthroid):
A tablet contains 75 mcg of levothyroxine. How many mg is this?
(Do not round. Use a leading zero but no trailing zero, if applicable. Label your answer.)
75 mcg / 1000 =
0.075 mg
ibuprofen liquid (Children's Motrin):
The order is for 15 mg/kg/day of ibuprofen for a child weighing 44 lbs. The drug is to be given twice daily. How many mg per dose?
(Round to the nearest tenth, if applicable. Use leading zero but no trailing zero, if applicable. Label your answer.)
44 lbs / 2.2 = 20 kg
20 kg x 15 mg = 300 mg a day
300 mg per day / 2 =
150 mg per dose
cephalexin (Keflex):
A doctor orders cephalexin for a child who weighs 63 lbs. The safe dosage range for this medication is 25–50 mg/kg/day. What is the safe dose range for this child?
(Round to the nearest tenth, if applicable. Use a leading zero but no trailing zero, if applicable. Label your answer.)
63 lbs / 2.2 = 28.6 kg
28.6 kg x 25mg = 715mg
28.6 kg x 50mg = 1430mg
Low: 715mg High: 1430mg
thyroxine (Eltroxin):
Order 100 mcg of thyroxine. Available: 0.05 mg each. How many tablets should the nurse administer?
(Round to the nearest tenth, if applicable. Use a leading zero but no trailing zero, if applicable. Label your answers.)
(100 mcg / 0.05 mg) x (1 / 1000) x 1 tablet =
2 tablets
cyancobalamin (Vitamin B-12):
A doctor orders 2500 mcg of cyancobalamin for a patient. The pharmacy sends a vial with 5 mg per mL. How many mL should the nurse administer?
(2500 mcg / 5 mg) x (1 / 1000) x 1 mL =
0.5 mL
acetaminophen (Tylenol):
Convert 1,250 mg of acetaminophen to grams.
(Round to nearest hundredth. Use a leading zero but no trailing zero, if applicable. Label your answer.)
1,250 mg / 1,000 =
1.25 g