Final answer:
To determine the amount of elixir that should be administered every 12 hours, we can use the given dosage and concentration. Using the ratio method, we find that 2 ml of the elixir should be administered every 12 hours.
Step-by-step explanation:
To determine the amount of elixir that should be administered every 12 hours, we need to consider the dosage ordered by the MD and the concentration of the available elixir.
The MD has ordered 50 mg to be given every 12 hours.
The elixir available is 125 mg/5ml.
To find the amount that should be administered every 12 hours, we can use the ratio:
125 mg --> 5 ml
50 mg --> x ml
Using cross multiplication, we can find that x ml = (50 mg * 5 ml) / 125 mg = 2 ml.
Therefore, 2 ml of the elixir should be administered every 12 hours.