Final answer:
To calculate the first dose of digoxin for a child weighing 48 lb, convert the weight to kilograms and then multiply by the recommended mcg per kilogram dosage range. The resulting total dose is then divided in half to find the initial dose range, which lies between 327.3 mcg to 436.4 mcg.
Step-by-step explanation:
The student has asked how much of the digoxin elixir should be given to a child who weighs 48 pounds for the initial dose. To find the correct dosage, first, we must convert the child's weight from pounds to kilograms, knowing that 1 kilogram equals approximately 2.2 pounds. This is important as the dosage is given in mcg per kilogram.
48 lb ÷ 2.2 lb/kg = 21.82 kg (rounded to two decimal places).
The recommended digitalizing dose of digoxin elixir for children 2 to 5 years old is 30 to 40 mcg/kg. Therefore, we multiply the child's weight in kg by the dosage range:
- 21.82 kg × 30 mcg/kg = 654.6 mcg
- 21.82 kg × 40 mcg/kg = 872.8 mcg
The first dose is half of the total digitalizing dose. Hence, the first dose will range from:
- 654.6 mcg ÷ 2 = 327.3 mcg
- 872.8 mcg ÷ 2 = 436.4 mcg
Therefore, the initial dose will fall in the range of 327.3 mcg to 436.4 mcg.