Jump to content

Reconstitution Problem- penicillin G potassium

Student Assist   (4,506 Views | 4 Replies)
by ljgeronsin ljgeronsin (New) New

467 Profile Views; 3 Posts

Hello!

So I am doing a dosage calculation worksheet for class and I just want to double check my answer. A classmate of mine said that because penicillin injections can be very painful to use more solution. However, I've read here and elsewhere to use as little as possible. His drug book said to use less than 100,000 units per mL which I'm not so sure about. Anyway...

1.Order: penicillin G potassium 600,000 units IM. The medication label reads:

ONE MILLION UNITS Penicillin G Potassium

Use sterile saline as diluent as follows:

Add Units per mL reconstituted solution

18.2 mL 250,000 units

8.2 mL 500,000 units

3.2 mL 1,000,000 units

I would think adding 3.2mL would be the most appropriate, you'd only have to give 0.6mL. Thoughts anyone? Thanks much in advance!

Share this post


Link to post
Share on other sites

loveofrn has 3 years experience as a BSN, RN and specializes in MICU.

347 Posts; 7,174 Profile Views

It is not about the unit that is closer.

Here is how to break it down to know how many ml to administer

Lets start with reconstitution

1) mixture of 1,000,000 unit with 18.2 ml= 250,000 unit per ml

This is dimensional analysis

(1,000,000 unit)*(1ml/250,000 unit)= 4 ml to administer

mixture of 1,000,000 unit with 8.2 ml= 500,000 unit per ml

(1,000,000 unit)*(1ml/500,000 unit)= 2 ml to administer

Mixture of 1,000,000 unit with 3.2 ml= 1,000,000 unit per ml

(1,000,000 unit)*(1ml/1,000,000)= 1ml to administer

PS: You can use any diluent but you have to know how many to administer if you use any one of them

Share this post


Link to post
Share on other sites

3 Posts; 467 Profile Views

Maybe my question wasn't clear. I was just curious if it would be better to give a less concentrated dose because the medication may cause pain or irritation. So instead of giving 0.6mL IM I could chose to do 1.2mL IM.

Share this post


Link to post
Share on other sites

SierraBravo has 3 years experience.

547 Posts; 8,351 Profile Views

There is an upper limit to the amount of volume you can give IM. For adults, I believe it is 3mL but I would have to double check it. In general, your patient will thank you if you can minimize the volume being given IM.

Share this post


Link to post
Share on other sites

loveofrn has 3 years experience as a BSN, RN and specializes in MICU.

347 Posts; 7,174 Profile Views

Maybe my question wasn't clear. I was just curious if it would be better to give a less concentrated dose because the medication may cause pain or irritation. So instead of giving 0.6mL IM I could chose to do 1.2mL IM.

It depends on the IM site. For deltoid, you can give up to 2 ml. For vastus lateralis and ventrogluteal, you can give up to 5 ml.

There is something called Z-track for IM injections (only ventrogluteal and vastus lateralis) which is used to reduce skin irritation and pain. The purpose of Z-track is to seal medication deep within muscle.

Again once you do your math, you can choose any IM site and inject the recommended amount the site can take.

If the patient is an adult and if it not a vaccine the prefer route is ventrogluteal

Share this post


Link to post
Share on other sites
×

This site uses cookies. By using this site, you consent to the placement of these cookies. Read our Privacy, Cookies, and Terms of Service Policies to learn more.