# Reconstitution Help!!!!!

Posted

I struggle so much with reconstitution, so can someone help me with this problem and give me tips or other examples that will help me please.

Order: Drug 300mg IV q 12 hr

On Hand: Drug 1g vials

Directions for reconstitution: For IM injection or IV infusion, reconstitute according to the following table. For IV administration, each dose must be further diluted with 10 ml of 0.9% NaCl.

Total volume of each dose of your infusion is _______.

Vial -Diluent to be added -Appox. average concentration

IM

1g -2.2ml -500mg/ml

IV Infusion

500mg -10ml -48mg/ml

1g -10ml -125mg/ml

This is what I did to get 56.3ml

ml= 1ml/48mg x 300mg/1dose

=300/48

= 6.25

= 6.3ml

6.3ml+50ml= 56.3ml

Edited by CordaeP

I must be really thick tonight, but I haven't the foggiest idea what you're talking about.

If you have one gram of drug in a syringe and you only want 300mg of it, top off the syringe to a full 10cc with NS or sterile water, roll to mix, and you have one gram in 10cc. If you discard 7cc of it, you'll have 300 mg in the syringe in 3cc. Then add it to whatever you're going to use to give it IV.

This is a dosage calculation problem that I am trying to figure out how to work out.

according to the chart you have been provided -- you would mix the 1g vial with 10 mL and have an avg concentration of 125 mg/ml (which seems high to me since 1000 mg/10 ml = 100 mg/ml).

if you need to administer 300 mg then 300/125 = 2.4 mL

Specializes in NICU, Trauma, Oncology. Has 7 years experience.

according to the chart you have been provided -- you would mix the 1g vial with 10 mL and have an avg concentration of 125 mg/ml (which seems high to me since 1000 mg/10 ml = 100 mg/ml).

if you need to administer 300 mg then 300/125 = 2.4 mL

Wouldn't it be 4.8ml since the reconstitution says for IV to add and additional 10ml NS, making total volume 20ml?

Edit ... Or would it be 12.4ml since it says (reread) an additional 10ml per dose?

i was going by the chart as written.. since it's a poorly written question as you have identified :)

Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma. Has 41 years experience.

O

rder: Drug 300mg IV q 12 hr

On Hand: Drug 1g vials

Directions for reconstitution: For IM injection or IV infusion, reconstitute according to the following table. For IV administration, each dose must be further diluted with 10 ml of 0.9% NaCl.

Total volume of each dose of your infusion is _______.

Vial -Diluent to be added -Appox. average concentration

IM

1g -2.2ml -500mg/ml

IV Infusion

500mg -10ml -48mg/ml

1g -10ml -125mg/ml

I'm sorry I am with GrnTea on this...what the heck?

When do you add the 10ml? If you have 1gm in 10ml how does that come out to 125mg/ml when you have a 1gm vial on hand?

If you have 1gram of drug in 2.2ml that is not 500mg per ml it's 500mgs per 1.1ml of drug and that would make it 454.5mgs/ml (so round it to 455mg/ml)

But using the given information.... if 500mgs in 10 mls is 48mgs/ml to give 300mgs is 6.25mls or rounded is 6.3mls = 300mgs.....10mls added would be total volume of 16.3mls

and if you have 125mgs/ml (even though 1gm/1000mgs in 10 mls is 100mgs/ml) and need to give 300mgs...you need 2.4mls for 300mgs...add 10 mls and you have a total of 12.4mls of fluid.

Is the problem you gave us exactly as the worksheet?

Specializes in SICU, trauma, neuro. Has 16 years experience.

I too would dilute it in 10 ml--always easier to divide/multiply by 10s/100s!

So then you'd have 1000 mg/10 ml=100 mg/ml.

100 mg/1 ml=300 mg/x ml and solve for x. ---> = 3 ml

Yes this is the exact problem. I got the 6.3 but I added 50ml because the problem said to further dilute it with 50 ml. I'm sorry the 10ml should be 50ml. I will edit it.

Further dilute should be 50ml not 10ml.

Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma. Has 41 years experience.

Ok...then

If you have 1gram of drug in 2.2ml that is not 500mg per ml it's 500mgs per 1.1ml of drug and that would make it 454.5mgs/ml (so round it to 455mg/ml)

But using the given information.... if 500mgs in 10 mls is 48mgs/ml to give 300mgs is 6.25mls or rounded is 6.3mls = 300mgs.....10mls added would be total volume of 16.3mls

and if you have 125mgs/ml (even though 1gm/1000mgs in 10 mls is 100mgs/ml) and need to give 300mgs...you need 2.4mls for 300mgs...add 10 mls and you have a total of 12.4mls of fluid.

if 500mgs in 10 mls is 48mgs/ml to give 300mgs is 6.25mls or rounded is 6.3mls = 300mgs plus 50ml = 56.3ml of total fluid

and...if you have 125mgs/ml (even though 1gm/1000mgs in 10 mls is 100mgs/ml) and need to give 300mgs...you need 2.4mls plus 50ml = 52.4ml total fluid

Specializes in NICU, Trauma, Oncology. Has 7 years experience.

Ok...then if 500mgs in 10 mls is 48mgs/ml to give 300mgs is 6.25mls or rounded is 6.3mls = 300mgs plus 50ml = 56.3ml of total fluid

and...if you have 125mgs/ml (even though 1gm/1000mgs in 10 mls is 100mgs/ml) and need to give 300mgs...you need 2.4mls plus 50ml = 52.4ml total fluid

Thanks Esme!