Incompatible IV meds

[wolfie]

Spotted something here that I don't understand:

Not too mention the ARF, SIRS, MRSA, and that you are a teetering a narrow balance from going into complete septic shock have your family threaten the nurse physically because she "hurt you" putting in a third IV because your IV meds aren't compatible and can't run in the same line. "but she has a perfectly fine working IV, can't we stop the heparin or the cardizem while the antibiotic is running?"

If the IV meds are incompatible (would have a nasty reaction - my guess is that they'd generate a substance that's either toxic, or that would gum up the line) and can't be put in the same line due to what would happen if they were mixed, why is it OK to put them in the same bloodstream? Wouldn't the reaction caused by their incompatibility happen there as well?

[TheSHAD0W]

They'd be mixed with the blood, which would tend to buffer and dilute them. It'd be possible to mix them in the same IV if they were properly buffered, but that would enormously increase the complexity of administering them.

[BlaqueKatt]

If the IV meds are incompatible (would have a nasty reaction - my guess is that they'd generate a substance that's either toxic, or that would gum up the line) and can't be put in the same line due to what would happen if they were mixed, why is it OK to put them in the same bloodstream? Wouldn't the reaction caused by their incompatibility happen there as well?

Most are incompatible because one lowers the available dose of the other.

I was on Magnesium Sulfate and also needed an antibiotic, the only antibiotic I could take would be rendered inert by the magnesium. However once the magnesium was diluted in my bloodstream it wasn't present in a large enough amount to do anything.

another example, my spouse is allergic to eggs, can't have an omlette, but he's fine with pancakes which are made with eggs, because the actual amount of egg in the pancake is minimal.

[Sapphire Silk]

If the IV meds are incompatible (would have a nasty reaction - my guess is that they'd generate a substance that's either toxic, or that would gum up the line) and can't be put in the same line due to what would happen if they were mixed, why is it OK to put them in the same bloodstream? Wouldn't the reaction caused by their incompatibility happen there as well?

As soon as the medications hit the blood stream, they are absorbed and compatibility issues become moot. It's if they mix in the line, or in syringe that there is the potential for a problem. Sometimes they form a precipitate (the normally clear solution turns milky white). Sometimes they inactivate the other medication, or combine to turn into something toxic.

But once in the blood, they are so dilute in the plasma this just isn't a concern.

Now there are many medications that are compatible in syringe that I will still administer separately IV, but combine for IM administration. For example, an opiod narcotic such as Dilaudid or Morphine combines quite well with Phenergan for nausea, and the two are often ordered to go together because the narc can contribute to nausea. The reason I separate them is because if I mix them IV, and the patient suffers an adverse reaction, I won't know which drug caused the problem.