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)

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

Verifying Safe Pediatric Dosages: Body Weight Method 3. Compare ordered dose to recommended dose Decide if dosage is safe

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.

Calculation of Safe Dosage Physician orders amoxicillin 200 mg p.o. q.8 hours for a child who weighs 22 lbs Is this dosage safe?

Calculation of Safe Dosage 1. Convert lb to kg Approximate equivalent: 1 kg = 2.2 lb Think: of 22 = 11 22 lb = 22  2.2 = 10 kg

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….”

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.

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

Calculation of Safe Dosage Maximum total daily dosage: 40 mg/kg/day × 10 kg = 400 mg/day 400 mg  3 doses = 133.3 mg/dose Single dosage is 66.7 to 133.3 mg per dose

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