In: Nursing
A 20ml vial of Retrovir contains 10 mg/mL IV infusion solution
So 1ml of injection contains 10mg of the drug
1 Vial of Retrovir = 20ml solution
20ml (one vial in total) contains 20 x 10 = 200mg.
Amount of Retrovir required per dose to be administered = 150mg in 150ml of D5W
Question 1: How many milliliters of Retrovir should be added to the IV fluids?
Answer : 15ml
We need only 150 mg of drug from the 200mg (20ml) vial
Method 1: 20 ml = 200 mg
Xml = 150mg
[Applying cross multiplication]
200X = 150 x 20
200X = 3,000
So X = 3,000 / 200 = 15
So 15ml = 150mg.
[Method 2: 1 ml = 10 mg, so 15 ml gives 150mg ]
Question 2: How many mL of fluids will be infused with each dose?
Answer : 165ml.
As stated in the question 150mg Retrovir to be added to 150ml D5W over 1 hour with a 15 gtts/mL administration set.
So 150mg Retrovir = 15ml of injection
150ml D5W + 15ml of Retrovir = 165ml
So total amount of fluid = 165ml.
Question 3: What is the drip rate for the infusion?
Answer : 41 gtts/min
Order is to administer Inj. Retrovir 150 mg (15ml) added to 150 mL of D5W 4th hourly over 1 hour with a 15 gtts/mL administration set.
Drops per minute = (Total volume to be administered x Drop factor (gtts/mL) / Time in minutes
Total volume to be administered = 165ml
Drop factor (gtts/mL) = 15 drops per min
Time in minutes = 1 hour = 60minutes
Drops per minute = (165 x 15) / 60
= 41.25 which can be rounded off as 41 drops per minute.
Question 4: How many milliliters of Retrovir will be discarded from the vial with each dose?
Answer : 5ml
Each vial contains 20ml from which only 15 ml is required as per the required dose. So 5ml will be remaining after withdrawing the required amount for each dose.