need help with math problem

Thank you so much for the help. That's the other thing that bothered me about this problem, should there be a safe dose range to go by?

Daytonight,

can I just say that "YOU'RE AWESOME"!

I've been on this site for about 6 months now and I've passed through many of your posts and replies to others. You seem to have so much knowledge and inspire me to be just that knowledgable and educated in nursing!

Thank you so much for the help. That's the other thing that bothered me about this problem, should there be a safe dose range to go by?

Yes, there is. But of course, that depends on the patient.

From Medscape (WebMD). Here's a link. (It's a great idea to register with this site, you'll find it a valuable resource):

http://www.medscape.com/druginfo/monograph?cid=med&drugid=5214&drugname=Cardizem+IV&monotype=monograph&secid=3

Thank you so much for the help. That's the other thing that bothered me about this problem, should there be a safe dose range to go by?

Source: Thomson Micromedex

Start at 5-10 mg/hour, increase in 5 mg increments up to *NO MORE THAN* 15 mg/hour up to 24 hours.

---

In practice at my facility I've (rarely) seen it up to 20 mg / hour for short durations on larger patients.

Note that this is discounting boluses often given before the drip is started.

When I bring up the link it is blank and I am a registered user of the website.

Oh crud. Let's see if this one works.

http://www.medscape.com/nurses

In the top search field, there's a tab for "drug" search. Type in Diltiazem IV

http://search.medscape.com/drug-reference-search?newSearch=1&queryText=diltiazem+IV

That should get you there. It's such a great resource, it's worth it to register and get the newsletters, updates and CMEs.

I didn't put this in the math problem, but on the first question it ask...your order states to start the infusion (Cardizem) at 0.5mg/kg/min. Which is way too much medication to start out with because the recommended doseage shouldn't exceed 15mg/hr.

then the next question had ask.....if the MD order stated to start the infusion at 5/mg/hr. at what rate would this be?

5mg/Hr x 50mL = 1 mL/hr

250mg

is this correct? and if so, they way the question is written with 5/mg/hr, does that mean it should be increased each time (5mg/hr) not to exceed 15mg/hr?

I didn't put this in the math problem, but on the first question it ask...your order states to start the infusion (Cardizem) at 0.5mg/kg/min. Which is way too much medication to start out with because the recommended doseage shouldn't exceed 15mg/hr.

then the next question had ask.....if the MD order stated to start the infusion at 5/mg/hr. at what rate would this be?

5mg/Hr x 50mL = 1 mL/hr

250mg

is this correct? and if so, they way the question is written with 5/mg/hr, does that mean it should be increased each time (5mg/hr) not to exceed 15mg/hr?

250 mg in 50 mL is a dangerously unsafe concentration-- you shouldn't hang it at all. It's concentrated for pharmacies to use one vial to make multiple admixtures off it.

i'm having difficulty understanding the question. i think it's because of the dilution instructions. it would depend on the concentration of the resulting final mixture. 2007 intravenous medications, 23rd edition, by betty l. gahart and adrienne r. nazareno lists the dilution and resulting dose and infusion rates for cardizem as follows:

• where the final concentration after dilution is 1mg/ml (125mg cardizem to 100ml of diluent) the dose and infusion rates would be
  • 5mg/hour = 5ml/hour
    
  • 10mg/hour = 10ml/hour
    
  • 15mg/hour = 15ml/hour

  [*]where the final concentration after dilution is 0.83mg/ml (250mg cardizem to 250 ml of diluent) the dose and infusion rates would be

  • 5mg/hour = 6mg/hour
    
  • 10mg/hour = 12ml/hour
    
  • 15mg/hour = 18ml/hour

  [*]where the final concentration after dilution is 0.45mg/ml (250 mg cardizem to 500 ml of diluent) the dose and infusion rates would be

  • 5mg/hour = 11ml/hour
    
  • 10mg/hour = 22ml/hour
    
  • 15mg/hour = 33ml/hour

after re-reading your original post and thinking on this a while (i am not familiar with using this drug) it sounds like the second group of figures would be what you are looking for and the answer would be 6ml/hour.

i think there are numerous typos on either the original post or in the problem given to solve. i'm fairly familiar with the drug and we typically always use a concentration of 1 mg / 1 ml to make it easy to titrate on the fly.

the question also says .25% ns, which is a clear typo on somebody's part: ns is 0.9%; a 0.25% solution would be extremely hypotonic.

I'm totally confused....our question had that the pharmacy sends you a 50mL bag of 0.25 NS with 250 mg of Cardizem added. I feel like they are trying to trick us, which is nothing unusal. What really bothers me is that we haven't been taught this, so it's really hard to know what to do with the problem. I've looked in the drug books and in our text books and they say to start the infusion at 0.25mg/kg; may repeat in 15 min with a dose of 0.35 mg/kg. may follow with continuous infusion at 10mg/hr (range 5-15mg/hr) for up to 24hrs.

I didn't understand why she put in the problem 5/mg/hr. most of the time you would see it as 5mg/hr, but this just seems different to me. could it mean that it would be increased in increments of 5 mg???

so would I take the 0.25mg/kg = 25mg divide by 250 x 50mL = 5mL/hr???

I so sorry to keep bothering you with this crazy problem, but it will drive me crazy until I either figure it out or someone can explain it to me how it should be done.

Thanks!!