IV vs PO abx

[Guest219794]

A while back, my Dad was in the ER with pneumonia- He drove himself there after a week or so of generalized symptoms.

Doc: Looks like we should admit him for a day or two.

Me: Why?

Doc: IV antibiotcs.

Me: Which one?

Doc: Levaquin.

Me: Given the excellent bio-availability of PO Levaquin, why not send him home with a prescription?

Doc: He might get worse despite treatment.

Me: I'll bring him back.

Doc: Sounds like a plan.

I work in an ER, and give a lot of IV antibiotics.

Often on admitted patients, and periodically have to start a line for one administration. (I really want to tell the patient to refuse, and request PO.)

Obviously, this is needed for PTs who cannot tolerate PO.

Other than that, is there any evidence anywhere that the preference for IV abx is supported?

One argument is the high concentrations needed for certain infections. But that can be maintained by appropriate dosing.

Another argument is for more rapid absorption. Maybe. This might be the case for a rapidly progressing infection, which is rarely the case. And, I would argue that on average, the patient getting IV abx (in the ER) reaches effective plasma concentration more slowly due to:

• Starting IV
  
• Obtaining the med, which may need to come from pharmacy
  
• Actual duration of administration
  
• Setting up a pump, and inevitable pump issues
  

I strongly suspect that, if studied, on average patients getting PO abx reach effective plasma concentrations earlier.

So- anybody know of any good evidence supporting the widespread practice of IV abx over PO?

[Wuzzie]

Look at your thread title!

[Jedrnurse, BSN, RN]

Well, I've always preferred oral antibiotics over PO ones...

[Meriwhen, ASN, BSN, MSN, RN]

I fixed the title for you before any more wisecracks are posted :)

I'm no IV medication expert (IM medications, on the other hand...), so bear that in mind as you read...

I would think that IV medications would reach and maintain therapeutic levels faster. Yes, there may be some more delays in starting an IV abx vs a PO one due to obtaining the med, starting IVs, titrating the dose over a period of time, etc. But consider that there may be delays in getting a PO abx from the pharmacy as well. Plus the fact that some abx may not be given directly with or for a period of time before/after certain foods and other PO medications. Then you have to consider how long it'll take the body to process the medication from the GI tract and get it into the system. Then you have to draw a level, and that may not be able to be done until after a few doses.

Whereas after you started the IV form, you'll already have a line in for future IV doses and for drawing levels. And those future doses will likely be delivered and ready to go by the time you have to administer it. IVs meds start working pretty much immediately, and I'd imagine it's probably easier to adjust and measure the level. Plus, you won't have to worry so much about food interactions (interactions with other meds are still possible though).

I didn't do a literature search for you, but I thought I'd throw that out there for you to consider.

[Guest219794]

I fixed the title for you before any more wisecracks are posted :)

I'm no IV medication expert (IM medications, on the other hand...), so bear that in mind as you read...

I would think that IV medications would reach and maintain therapeutic levels faster. Yes, there may be some more delays in starting an IV abx vs a PO one due to obtaining the med, starting IVs, titrating the dose over a period of time, etc. But consider that there may be delays in getting a PO abx from the pharmacy as well. Plus the fact that some abx may not be given directly with or for a period of time before/after certain foods and other PO medications. Then you have to consider how long it'll take the body to process the medication from the GI tract and get it into the system. Then you have to draw a level, and that may not be able to be done until after a few doses.

Whereas after you started the IV form, you'll already have a line in for future IV doses and for drawing levels. And those future doses will likely be delivered and ready to go by the time you have to administer it. IVs meds start working pretty much immediately, and I'd imagine it's probably easier to adjust and measure the level. Plus, you won't have to worry so much about food interactions (interactions with other meds are still possible though).

I didn't do a literature search for you, but I thought I'd throw that out there for you to consider.

Thanks for changing the title, though I probably deserve the wisecracks.

Levels are really only done for Vanco, as far as I know.

As far as the IV meds working faster, maybe some. But even when they do, that only matters if it is rapidly progressive.

I have read (really scanned) a bunch of the literature, and none of seems to support IV over PO.

For example:

Antibiotics that are well absorbed after oral administration are available, and the best current evidence suggests they are safe and effective for many conditions.

Belief in the superiority of intravenous antibiotics is widespread among health professionals and patients, but it is not supported by good evidence.

Or:

What's so magical about the route of antibiotic administration? I can understand how lay persons may perceive parenteral antibiotics as "stronger," but sometimes I think medical personnel fall victim to the same misconception.

Or:

The present results document the efficacy of ciprofloxacin in the initial empirical management of severe UTIs, and show that the oral regimen is as effective as the intravenous one

[Wuzzie]

Thanks for changing the title, though I probably deserve the wisecracks

Hopefully you know they were all in good fun!

[Jedrnurse, BSN, RN]

Hopefully you know they were all in good fun!

Oh, I thought it was a matter of oral vs. p****d o** (PO) medications...

[Guest219794]

I fixed the title for you before any more wisecracks are posted :)

I'm no IV medication expert (IM medications, on the other hand...), so bear that in mind as you read...

I would think that IV medications would reach and maintain therapeutic levels faster. Yes, there may be some more delays in starting an IV abx vs a PO one due to obtaining the med, starting IVs, titrating the dose over a period of time, etc. But consider that there may be delays in getting a PO abx from the pharmacy as well. Plus the fact that some abx may not be given directly with or for a period of time before/after certain foods and other PO medications. Then you have to consider how long it'll take the body to process the medication from the GI tract and get it into the system. Then you have to draw a level, and that may not be able to be done until after a few doses.

Whereas after you started the IV form, you'll already have a line in for future IV doses and for drawing levels. And those future doses will likely be delivered and ready to go by the time you have to administer it. IVs meds start working pretty much immediately, and I'd imagine it's probably easier to adjust and measure the level. Plus, you won't have to worry so much about food interactions (interactions with other meds are still possible though).

I didn't do a literature search for you, but I thought I'd throw that out there for you to consider.

Thanks for changing the title, though I probably deserve the wisecracks.

Levels are really only done for Vanco, as far as I know.

As far as the IV meds working faster, maybe some. But even when they do, that only matters if it is rapidly progressive.

I have read (really scanned) a bunch of the literature, and none of seems to support IV over PO in many, if not most cases.

For example:

Antibiotics that are well absorbed after oral administration are available, and the best current evidence suggests they are safe and effective for many conditions.

Belief in the superiority of intravenous antibiotics is widespread among health professionals and patients, but it is not supported by good evidence.

Or:

What's so magical about the route of antibiotic administration? I can understand how lay persons may perceive parenteral antibiotics as "stronger," but sometimes I think medical personnel fall victim to the same misconception.

Or:

The present results document the efficacy of ciprofloxacin in the initial empirical management of severe UTIs, and show that the oral regimen is as effective as the intravenous one

[Meriwhen, ASN, BSN, MSN, RN]

Hopefully you know they were all in good fun!

Heck, I was tempted to throw in a one-liner myself. Then I remembered that I work here

[KelRN215, BSN, RN]

Levels are really only done for Vanco, as far as I know.

And gent, tobra and amikacin. Those were the big ones I saw providers order levels on when I worked in home infusion.

For pneumonia, in my experience, oral antibiotics are usually trialed first. I rarely got referrals for IV antibiotics for pneumonia when I was working as an infusion liaison.

Actually, I would say, for the majority of my patients at that job, they failed POs before they were referred for long term IV antibiotics. The exception was the CF patients. Sometimes they trialed POs first but for some, it was IV antibiotics for any exacerbation That was also based on a long history, though.

[Kallie3006, ADN]

IV abx bioavailability is 100% where PO depends on the med.

IV is preferred on infections in a part of the body where PO abx penetration is less effective

Absorption factors that are patient dependent

IV abx meet peak concentration levels faster than PO (depending on the med)

IV antibiotics are given due to the increased amount of resistant infections where PO effectiveness has declined

IV antibiotics bring in more money

[LibraSunCNM, BSN, MSN, CNM]

There's also the factor of all of the zillions of lovely bugs he could pick up during a hospital stay to treat his own bug. The healthcare system royally sucks on a lot of levels.