Chapter 10 • Calculate doses of medications for children and adults using body weight • Calculate doses of medications for children using Clark’s rule • Calculate doses of medication for special populations based on body surface area • Calculate doses of medication for infants using Fried’s rule • Calculate doses of medication for children using Young’s rule Pretest Complete the following calculations for pediatric patients on the basis of age and body weight. The nomogram necessary for calculating some of these exercises can be found on p. 359. Show your calculations. Show your answers in tenths for strengths calculated for weights in the metric, apothecary or household system unless otherwise noted. Be sure your answer is a measurable dose for solids or volume measurements as appropriate unless otherwise noted. What is the exact volume dose (in hundredths) for the child using the label provided? ____________________ How many mcg of Lanoxin should be administered to the child? ____________________ What is the measurable volume of Lanoxin to be administered? ____________________ What would be the child’s dose in the metric system? ____________________ If the phenobarbital available is the label shown, what volume of medication would the child receive? ____________________ Show the correct volume of medication to be provided on the measuring device. What is the dose for the child? ____________________ What volume of medication should be given to the child using the label provided in hundredths? ____________________ What is the measurable dose? ____________________ Show the correct volume of medication to be provided on the measuring device. What is the measurable volume to be given using the provided label? ____________________ What is the dose to be given in mg? ____________________ What is the dose in household measurements? ____________________ What dose should the child receive? ____________________ What volume of medication should be given if the label shown is used? ____________________ What is the dose for the child based on the child’s age? ____________________ With the label shown, what is the volume of medication to be given? ____________________ What is the measurable dose volume in household measurements?____________________ Is this an acceptable dose according to labeled manufacturer’s dose? ____________________ What is the dose for the child based on body weight? ____________________ Using the measuring devices shown, what is the volume of medication to be administered per dose? ____________________ What is the dose of Biaxin for this child in hundredths? ____________________ Using the label given, what measurable volume of medication should be given to the child per dose? ____________________ Show the correct volume of medication to be provided on the measuring device. What is the dose to be given for this child with each administration? ____________________ What is the volume of medication to be given for this dose? ____________________ What should be the dose for the infant? ____________________ What volume of medication should be administered? (Round to the nearest hundredth.) ____________________ What is the measurable dose to be administered? ____________________ Show the correct volume of medication to be provided on the measuring device. What should be the dose for this child based on the adult dose? ____________________ What volume of medication should be administered to the child? ____________________ Using the dosage calculated, what dose should be approximated in the solid form of medication given in label B? ____________________ Explain your decision on the dose of solid medication to be administered. ____________________ Show the correct volume of medication to be provided on the measuring device. What is the dose to be administered if the adult dose is 500 mg/dose? ____________________ Using the label, how many capsules should be given to the child with each dose? ____________________ Round to the whole number for the total dosage per day. What is the strength of each dose for administration to the child using the Lorabid label shown? ____________________ What is the measurable volume of each dose of medication for administration? ____________________ What is the total dosage of Lorabid to be given in a day? ____________________ What should be the strength per dose for the child aged Using the label shown, what volume of the medication should be given with each dose? ____________________ What measuring device could be used to best supply this amount of medication to a child of this age? ____________________ Again, ounces may be canceled and the means and extremes multiplied or Now convert total weight to kilograms for the child weighing 18.25 lb. The steps for calculating mg/kg are as follows: 1. Obtain the weight of the patient, and calculate that weight into kilograms. 2. Read the physician’s order for the strength or weight of the medication that is to be provided to the patient. 3. Complete the calculation of medication of “mg/kg” by multiplying. 4. After obtaining the dose of medication to be administered, use the ratio and proportion, dimensional analysis, or formula method to calculate the dose in either solid tablets or capsules or volume of liquid medication as shown in Chapters 7 and 8. If the medication needs reconstitution, use the knowledge from Chapter 9 to reconstitute the medication. Example 10-1 First you need to change pounds to kilograms: Example 10-2 What would be the strength of each dose? ____________________ What amount or volume of medication should be given as a dose? ____________________ First convert the pounds to kilograms and round to the nearest kilogram. If you need to review the mathematical calculations for doses of liquid medications, refer to Chapter 8. If the medication is in a solid form, review Chapter 7 as needed. OR if weight in kilograms is to be used, the calculation formula would be
Calculation of Medications for Special Populations Based on Body Weight and Patient Age
1 The adult dose of amoxicillin is 500 mg tid.
2 The adult dose for Augmentin is 500 mg tid.
3 A child weighing 54 lb is to take phenobarbital. The physician orders 1 mg/kg tid.
4 An 8-month-old infant is ordered Demerol following surgery. The normal adult dose is meperidine 50 mg.
5 A child weighs 55 lb and has an order for acetaminophen on the basis of body weight. The adult dose is 325 mg.
6 A child has an order for digoxin based on 8 mcg per kilogram of body weight. The child weighs 35 lb.
7 An 8-year-old child is to receive phenobarbital, and the adult dose is phenobarbital gr 
.
8 A physician orders Zantac syrup for a 10-month-old child. The adult dose is 150 mg bid.
9 A child weighs 66 lb and is of normal height for weight. The physician orders Benadryl elixir to be given based on body surface area. The adult dose is 50 mg q8h prn.
10 A child 10 years old has bronchitis, and the physician orders Keflex suspension. The normal adult dose is 500 mg bid. Use age of the child and the normal adult dose as the basis for your answer.
11 A child age 5 years 4 months is ordered Colace syrup. The adult dose is Colace 100 mg hs.
12 A child weighs 88 lb, and the physician orders Compazine syrup 0.5 mg/kg tid.
13 A child weighs 84 lb. The physician orders Biaxin oral suspension 10 mg/kg bid in divided doses.
14 A child weighs 56 lb and is 40″ tall. He has been diagnosed as having epilepsy. The physician orders Dilantin suspension for this child to be based on BSA. The normal adult dose is Dilantin 300 mg per day in three divided doses.
15 A 9-month-old child is to receive Dilantin according to the following label. The adult dose is Dilantin 100 mg.
16 A child is 12 years old and is to receive Dilantin according to label A. The adult dose is Dilantin 200 mg qam.
17 A child weighing 75 lb has otitis media. The physician orders Keflex to be given tid.
18 A child weighing 45 lb has been prescribed Lorabid 15 mg/kg/day in divided doses bid.
19 A child weighing 33 lb has an order for Epivir bid. The adult dose is Epivir 150 mg bid.
years? ____________________
20 An 8-year-old child is being treated for a urinary tract infection. The usual adult dose for Furadantin is 100 mg.
Calculating Medication Doses By Body Weight
Use Of Clark’s Rule For Pediatric Dosage
Stay updated, free articles. Join our Telegram channel
Tech Alert
A child who has been diagnosed with epilepsy weighs 53 lb. The physician orders Dilantin 30 mg Kapseals to be given at 2.5 mg/kg/dose. What dose of the medication should be given to this child? 
A physician orders amoxicillin 20 mg/kg/day to be given q8h to a child who weighs 42 lb. The concentration of amoxicillin is 125 mg/mL. What would be the dosage for the day? ____________________
A physician orders amoxicillin 20 mg/kg/day to be given q8h to a child who weighs 42 lb. The dosage strength of amoxicillin is as shown above at 125 mg/mL. (The q8h would be a 3-times-a-day dosage—therefore the use of 3 doses in the formula.)
Tech Alert
Full access? Get Clinical Tree
