Question

ordered 1.0g of tetracycline to be given every 6 hours. on hand 500mg. how many will we need for 1 days treatment?

Answer 1

How many hours in a day. 24 hours?

Once every 6 hours means four doses per day.
Each dose is 1.0 g so you will need 4 grams. You already have 0.500 g so you will need another 3.5 g? Check it out.