diluting meds??

I have a quick question that is driving me crazy. Please help. It is regarding diluting meds. For example order: Ranitidine 50mg ivp. The patient has LR TKO. In the med book it states to dilute 50mg in 20 mls of NS. After dilution, does this change the dosage? For example, would you give 2.5 ml because when the med is diluted it changes the dosage or the full 20 ml? Hope this is not confusing some. Is there some dosage calculation for diluted meds? Any help will be appreciated.

No it does not change the dosage. On the packages of medications it is more clear, because you will realize that you are diluting 50 mg (in usually a powder form of the drug) with the 20 mL of NS. Then the pt will get all of the 20 mL because you only have 50 mg of the drug. Some diluting is more difficult, and you do have to do a dosage calcualtion. But that is usually medication for injection, not for PB administration. In my internship last month we had Solumedrol single dose vials that were 125 mg. You diluted the powder with 2 mL of NS. However the doctor only ordered 60 mg. So I only drew up 0.96 mL into the syringe. I hope this makes sense!!!