Pediatric Dosage Calculation Hello Class!!!!!!! Good luck in college.

How is Pediatric Dosage Calculation Different than Adults? There is no standard dose All doses are based on a recommended dosage based on: Body weight in kilograms (for this dosage test) Body Surface Area

Begin by Converting to Kilograms All MD orders will be ordered as a dose per kg Convert the patient’s weight in lbs to kg by dividing the weight in lbs by 2.2 Example: 50 lbs divide by 2.2 = Round to tenths place = 22.7 kg

Now you try! 1. Patients weight 48 lbs How many kg does the patient weigh? Patient weight 13.9 lbs How many kg does the patient weigh?

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The MD order The MD order can be written in several ways: In a daily total to be divided in equal doses Ex: 30mg/kg/day equally divided in three doses or Per dose Ex: 30mg/kg TID

Lets Try it! Patients weight: 45 lbs 2. Give 30mg/kg/day equally divided in three doses How many mg per dose? How much is the 24 hr drug total? 3. Give 30mg/kg TID How many mg per dose? How much is the 24 hr drug total?

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Is the dose safe? All pediatric dosages have a recommended range in the drug guide These ranges are typically based on a 24 hour total amount of a dosage in mg, mcg, gm, etc. Remember how to convert mcg to mg, gram to mg etc.

Is the order safe? A statement from the drug guide will be provided on the dosage test Ex: The drug guide states the recommended safe dosage is 3-5 mg/kg/day to be given in 2 divided doses

Lets try it! 4. MD order Sporanox (itraconazole) 40 mg bid Patients weight 47 lbs Drug guide recommends 3-5mg/kg/day q12 hrs Is the dose safe?

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Supply Pediatric medication is typically supplied in liquid form Some children can swallow pills or the medication may only come in tablet form Most of the dosage assessment questions will consist of medication in liquid form, few questions will be in tablet form

Remember…. Supply is expressed as a dosage amount per a commonly used quantity Example 250mg/5ml 100mg/ml 50mcg/1ml This is different from the total amount of drug dosage in the bottle

Calculate Liquid Medication Dose desired Dose on handX quantity in ml = volume to be administered

Lets try it! 5. MD order is to give 75 mg Supply is 250mg/5ml Calculate the amount to administer

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Read a label Some dosage questions will require you to read a drug label Mixing directions: Add 30 ml of water Mix Vigorously Discard after 5 days Zantac (ranitidine) Oral suspension 25mg/5ml

Lets try it! 6. Using the medication label supplied, how many milliliters should be administered per dose if the MD order is 100 mg po qd?

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Ok, so how do you round? Look at it this way… –If the calculated answer is <1 ml then round to the hundredths place as this amount could be easily administered in a 1 ml syringe Example: If the answer was 0.75 ml, where would you draw the solution to in this syringe?

What if the Answer is > 1 ml? If the calculated dose is greater than 1 ml then you round to the tenths place Example- if the dose was 2.75 ml, using a 3 ml syringe you would need to round to 2.8ml, as 2.75ml can not be precisely administered

For Example If the answer is Round to 0.38ml…..don’t forget the zero in the ones place! If the answer is Round to 1.4 ml

NEVER……. Round to a whole number!!!!! If the answer is Round to 1.9 ml NOT 2 ml

So Remember: < 1 ml rounds to 2 places to the right of the decimal place >1 ml, kg, mg, mcg, anything else rounds to only 1 place to the right of the decimal place

Practice Rounding If you calculated the answer to be: a mg, round to:__________ b ml, round to:_________ c ml, round to:__________ d , round to:__________ e kg, round to:_______

Intravenous Nothing new here…. Volume in ml x drop factor = gtt/min Time in min

You are Ready!!! Lets put it all together 8. The physician orders Kantrex (kanamycin) oral suspension po 150 mg/kg/day in 2 divided doses. Supply Kantrex 500mg/5ml. Patients weight: 28 lbs How many milliliters should be administered per dose?

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9. The physician orders Prostigmin (neostigmine bromide) 8 mg q 4 hrs The drug guide recommended dosage is 2-4 mg/kg/day in divided doses Patients weight: 21 lbs Is the physicians order safe?

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Careful…some may have patients weight in kg already! 10. The physician orders Primacor (milrinone lactate) 50 mcg IM stat. Supply: 0.2mg/ml Patients weight: 12 kg. How many milliliters should be administered per dose?

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11. The physician orders Sustiva (efavirenz) 20mg/kg po q 12 hrs. Supply: Sustiva 50 mg tablets Patients weight: 11 lbs How many tablets are to be administered per dose?

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12. The physician orders IV fluids as follows: Infuse 1000ml of 0. 45% normal saline solution in 10 hours IV. Calculate the flow rate when the drop factor is 10 drops per milliliters

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You are ready to take the practice test!