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Pediatric and Adult Dosages
Based on Body Weight
Chapter 13
Verifying Safe Pediatric Dosages:
Body Weight Method
• 1. Convert child’s weight from
pounds to kilograms (rounded to tenths)
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Verifying Safe Pediatric Dosages:
Body Weight Method
• 2. Calculate safe dosage in mg per kg or
mcg per kg (rounded to tenths) for a child
of this weight
– As recommended by a reputable drug
reference
– Multiply mg per kg by child’s weight in kg
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Verifying Safe Pediatric Dosages:
Body Weight Method
• 3. Compare ordered dose to
recommended dose
– Decide if dosage is safe
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Verifying Safe Pediatric Dosages:
Body Weight Method
• 4. If safe
– Calculate amount to administer dose
– If dosage seems unsafe, consult with
ordering practitioner
– NOTE: Dosage per kg may be mg per kg, mcg
per kg, g per kg, mEq per kg, units per kg,
milliunits per kg, etc.
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Calculation of Safe Dosage
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•
Physician orders amoxicillin 200 mg p.o.
q.8 hours for a child who weighs 22 lbs
Is this dosage safe?
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Calculation of Safe Dosage
1. Convert lb to kg
 Approximate equivalent: 1 kg = 2.2 lb
– Think: 21 of 22 = 11
– 22 lb = 22  2.2 = 10 kg
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Calculation of Safe Dosage
• 2. Calculate recommended dosage
– Look at label Amoxil (amoxicillin)
– Label describes recommended dosage as “20 to
40 mg per kg per day in divided doses every 8
hours….”
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Calculation of Safe Dosage
– The label recommends that total daily dosage
be divided and administered every 8 hours,
resulting in 3 doses in 24 hours.
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Calculation of Safe Dosage
• Calculate minimum and maximum
dosage for each single dose
• Minimum total daily dosage:
– 20 mg/kg/day × 10 kg = 200 mg per day
• Minimum dosage for each single dose:
– 200 mg  3 doses = 66.7 mg per dose
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Calculation of Safe Dosage
• Maximum total daily dosage:
– 40 mg/kg/day × 10 kg = 400 mg/day
• Maximum total daily dosage:
– 400 mg  3 doses = 133.3 mg/dose
– Single dosage is 66.7 to 133.3 mg per dose
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Calculation of Safe Dosage
• 3. Decide if ordered dosage is safe
– 200 mg
– Allowable, safe dosage is 66.7 to 133.3 mg per
dose
• No, this dosage is too high and is not safe.
• 4. Contact physician to discuss order
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