Final answer:
To find the number of capsules, convert the physician's order from grams to milligrams. Divide the total amount of the drug on hand per capsule by the amount prescribed per capsule. The patient would need to take half a capsule to get 0.5 grams of cephalexin.
Step-by-step explanation:
To find the number of capsules, we need to convert the physician's order from grams to milligrams. 0.5 grams is equal to 500 milligrams. Next, we divide the total amount of the drug on hand, which is 250 milligrams per capsule, by the amount per capsule prescribed by the physician (500 milligrams) to find the number of capsules needed. So, the calculation would be 250 milligrams/capsule ÷ 500 milligrams/capsule = 0.5 capsules per dose. Therefore, the patient would need to take half of a capsule to get 0.5 grams of cephalexin.