Treatment of UTI in Elderly Patients on warfarin?

[Rockinacoustic]

I see this prescription often at work: Elderly patient with a UTI who is on warfarin therapy, so the doctor writes for Macrobid, which will do nothing but increase risk of AE's given their renal function.

Bactrim and FQ are a no-go because complicated infections require > 3 days of therapy, which will alter INR. Beta-lactams have resistance issues, although Augmentin is said to have some efficacy.

Any viable alternatives, or would you just dispense?

---

Members don't see this ad.

 

[thephoenician88]

I see this prescription often at work: Elderly patient with a UTI who is on warfarin therapy, so the doctor writes for Macrobid, which will do nothing but increase risk of AE's given their renal function.

Bactrim and FQ are a no-go because complicated infections require > 3 days of therapy, which will alter INR. Beta-lactams have resistance issues, although Augmentin is said to have some efficacy.

Any viable alternatives, or would you just dispense?

what's her crcl? do you know or just assuming she has poor renal function.

 

[Rockinacoustic]

what's her crcl? do you know or just assuming she has poor renal function.

This is merely assumption- I'm speaking from a community perspective so I have no access to labs, nor do I think the PCP or urgent care center who wrote the prescription would have gotten a SCr.

The patient in question was a 79 yo female given 5 days of Macrobid fwiw.

Granted, this isn't one of those end of the world contraindications. I'm just curious what others would do.

 

[Sparda29]

IMO, you can use Bactrim and/or FQ as long as you alter the dose of warfarin. Probably easier in hospital since we can monitor INR day to day.

 

[chibipinkneko]

I'm assuming this is an uncomplicated UTI. You need a ClCr of 60 to achieve therapeutic concentrations of Macrobid in the urine, and at 79 she won't have this unless she weighs 83 kg. This is assuming she has a SrCr of 1 or lower. So they're just creating resistant bacteria. If this is an uncomplicated infection, Augmentin has good, but not great activity against E.coli and Klebsiella. It also covers Staph and Enterococcus. Also, even if she did have a ClCr of 60, isn't the treatment duration with Macrobid for 7 days? How about Fosfomycin?

 

[npage148]

Macrobid would be fine with me. Or dicloxicillin ?

 

[lactonerx]

Augmentin for outpatient treatment in a patient who does not follow up for INR checks regularly seems reasonable

 

[Rockinacoustic]

I'm assuming this is an uncomplicated UTI. You need a ClCr of 60 to achieve therapeutic concentrations of Macrobid in the urine, and at 79 she won't have this unless she weighs 83 kg. This is assuming she has a SrCr of 1 or lower. So they're just creating resistant bacteria. If this is an uncomplicated infection, Augmentin has good, but not great activity against E.coli and Klebsiella. It also covers Staph and Enterococcus. Also, even if she did have a ClCr of 60, isn't the treatment duration with Macrobid for 7 days? How about Fosfomycin?

I was taught unless you're non-pregnant adult female < 45 yo, you should be treated as a complicated case. Otherwise I'd have called and suggested 3 days of Cipro.

 

[chibipinkneko]

I was taught unless you're non-pregnant adult female < 45 yo, you should be treated as a complicated case. Otherwise I'd have called and suggested 3 days of Cipro.

Ah okay, thanks 🙂 It was never clearly delineated for us in school. Fosfomycin and Macrobid are only for non-complicated cases right? I would suggest Augmentin then, or have her warfarin dose titrated because she'll need to be on Septra or a FQ for 1-2 weeks :S

 

[Praziquantel86]

There are so many blanket statements in this thread that are incorrect or partially true. Look beyond what you were taught in school and actually find out the actual answer.

Some questions to ponder: what literature supports a specific CrCl cutoff for nitrofurantoin (not saying that it should be used in this case, but the answer varies significantly depending on who you ask and where you look). Since when is being >45 make all UTIs complicated? What is the minimum length of treatment for simple cystitis? Why would cipro not be a good choice for empiric treatment? Is fosfomycin useless for anything other than "uncomplicated" UTIs?

Before you question prescribing practices, it helps to have your ducks all in a row. Otherwise when people ask you for anything supportin your recommendations beyond your good intentions, you'll be SOL.

 

[chibipinkneko]

There are so many blanket statements in this thread that are incorrect or partially true. Look beyond what you were taught in school and actually find out the actual answer.

Some questions to ponder: what literature supports a specific CrCl cutoff for nitrofurantoin (not saying that it should be used in this case, but the answer varies significantly depending on who you ask and where you look). Since when is being >45 make all UTIs complicated? What is the minimum length of treatment for simple cystitis? Why would cipro not be a good choice for empiric treatment? Is fosfomycin useless for anything other than "uncomplicated" UTIs?

Before you question prescribing practices, it helps to have your ducks all in a row. Otherwise when people ask you for anything supportin your recommendations beyond your good intentions, you'll be SOL.

Well, what do you recommend?

 

[Praziquantel86]

Well, what do you recommend?

I don't know the patient, so I have no recommendations. Those are general questions. It just irks me to see misinformation floating around with little to back it beyond "that's what I was taught".

 

[rxlea]

I would ask some questions/gather info first:

Comorbidities like diabetes?
Recurrent UTIs?
Did she have a recent UTI and if so, what did they use?
Sexually active?
Allergies?
Any topical estrogens being used?

FQ have variable resistance patterns and, again, you'd need to assess her other Comorbidities and drug regimens. Most elderly-- polypharmacy. Usually only used if you can't use other things.

I'm fairly certain Bactrim is a no go/not recommended for empiric tx in older women but I'd have to look it up.

So much info needed!

 

[chibipinkneko]

I don't know the patient, so I have no recommendations. Those are general questions. It just irks me to see misinformation floating around with little to back it beyond "that's what I was taught".

What makes a complicated UTI case? I was never clear on that. .

Ah okay. Well I was never shown the research behind the fact that Nitrofurantoin is only effective if ClCr >60. Do you have a link to the research behind it? According to the IDSA guidelines for an uncomplicated urinary tract infection, Nitrofurantoin can be used for 5-7 days. 5 Days have as much efficacy as 7 days, at least according to these guidelines by the IDSA, so I guess I was wrong about that. Cipro and Septra are effective for 3 days, according to this IDSA document: http://cid.oxfordjournals.org/content/29/4/745.long

The problem with Fosfomycin is that there isn't a lot of evidence to support it's use in complicated infections. According to this article there have been case reports of it's use in complicated infections: http://journals.lww.com/infectdis/Fulltext/2001/06000/Fosfomycin__A_Review_.4.aspx

But it would only be used as a last resort until there is more evidence. It is not mentioned in the IDSA guidelines for treatment of a complicated infection.

So I'm still left wondering why Nitrofurantoin is not used in complicated UTI's. It is not effective against Psuedomonas or Enterococcus faecium, which you have to worry about with complicated infections. Although if a patient has Enterococcus faecium, you're left with very little choices :S

Thanks for your help 🙂

 

[chibipinkneko]

Is this patient in a retail setting or a hospital because in a retail setting you get very little patient information, and that makes it hard for the pharmacist to know if it's the right antibiotic.

 

[chibipinkneko]

I would ask some questions/gather info first:

Comorbidities like diabetes?
Recurrent UTIs?
Did she have a recent UTI and if so, what did they use?
Sexually active?
Allergies?
Any topical estrogens being used?

FQ have variable resistance patterns and, again, you'd need to assess her other Comorbidities and drug regimens. Most elderly-- polypharmacy. Usually only used if you can't use other things.

I'm fairly certain Bactrim is a no go/not recommended for empiric tx in older women but I'd have to look it up.

So much info needed!

The Bactrim isn't good in this patient because of her warfarin use, although you could monitor her INR closely, though I'm not sure how often you would need to monitor it.

 

[rxlea]

The Bactrim isn't good in this patient because of her warfarin use, although you could monitor her INR closely, though I'm not sure how often you would need to monitor it.

Yes, but it's not a good choice anyway warfarin or not possibly because of her age as well as other factor s

 

[Thoughtfulsinner]

Unless you are the one prescribing the medication, who cares? Just fill the prescription handed to you and go on with your day.

 

[rxlea]

Is this patient in a retail setting or a hospital because in a retail setting you get very little patient information, and that makes it hard for the pharmacist to know if it's the right antibiotic.

True but you can still talk to the patient for some of it-- like if she had it before, how long ago, etc. you can look in her profile to see what else she is taking to see if she is diabetic, has had other things that would have been used for UTI,, etc.

 

[npage148]

Swich it to bactrim and tell her to cut 1/3 off her warfarin tablet each day. Should even out

 

[Rockinacoustic]

I keep trying to stress this in in a community setting.

Prazi and Lea raise some excellent questions. Perhaps I'm oversimplifying this scenario.

One certainly could check the profile to see the last time macrobid (if any) was dispensed. Allergies and any co-morbidities like diabetes are obtainable information as well.

I can't find an article specifically stating a CrCl < 60 is an absolute contraindication for macrobid... but it is on the Beer's Criteria for that exact reason now.

 

[rxlea]

What makes a complicated UTI case? I was never clear on that. .

Ah okay. Well I was never shown the research behind the fact that Nitrofurantoin is only effective if ClCr >60. Do you have a link to the research behind it? According to the IDSA guidelines for an uncomplicated urinary tract infection, Nitrofurantoin can be used for 5-7 days. 5 Days have as much efficacy as 7 days, at least according to these guidelines by the IDSA, so I guess I was wrong about that. Cipro and Septra are effective for 3 days, according to this IDSA document: http://cid.oxfordjournals.org/content/29/4/745.long

The problem with Fosfomycin is that there isn't a lot of evidence to support it's use in complicated infections. According to this article there have been case reports of it's use in complicated infections: http://journals.lww.com/infectdis/Fulltext/2001/06000/Fosfomycin__A_Review_.4.aspx

But it would only be used as a last resort until there is more evidence. It is not mentioned in the IDSA guidelines for treatment of a complicated infection.

So I'm still left wondering why Nitrofurantoin is not used in complicated UTI's. It is not effective against Psuedomonas or Enterococcus faecium, which you have to worry about with complicated infections. Although if a patient has Enterococcus faecium, you're left with very little choices :S

Thanks for your help 🙂

Complicated UTI means that there is a higher risk for failed treatment because of GU abnormalities (BPH, renal caniculi, etc.), immunocompromised status, or MDR infection. Other bacteria are of concern rather than just your typical e coli. It's also important to recognize if it's cystitis or pyelonephritis...

Macrobid is good for cystitis but not so much for pyelonephritis...

That's why it's important to know if she has recurrent UTIs, Comorbidities (diabetics especially with poorly controlled diabetes will probably require longer length of treatment), or if she has recently taken anything else like FQ, cephalexin, etc.

 

[Praziquantel86]

What makes a complicated UTI case? I was never clear on that.

Lea has a pretty good explanation above, so I won't go further - the strict definition can be found in the guidelines. When you read those, note the amount of "expert opinion" with limited data available. Then look into the recent research about duration of treatment for those with complicated UTIs and realize that the duration keeps getting shorter and shorter.

Ah okay. Well I was never shown the research behind the fact that Nitrofurantoin is only effective if ClCr >60. Do you have a link to the research behind it? According to the IDSA guidelines for an uncomplicated urinary tract infection, Nitrofurantoin can be used for 5-7 days. 5 Days have as much efficacy as 7 days, at least according to these guidelines by the IDSA, so I guess I was wrong about that. Cipro and Septra are effective for 3 days, according to this IDSA document: http://cid.oxfordjournals.org/content/29/4/745.long

That's because there is none. This paper (http://www.theannals.com/content/47/1/106.abstract) unfortunately didn't exist until a few weeks ago, so I had to discover that myself. Don't always believe what you're told - especially the "moderate evidence level" behind the Beers recommendation. Not saying you should use nitrofurantoin in the elderly, but its absurd to think that 60 is a hard and fast cutoff based on poor data from 1967. There's a paper from 1968 that says 20 is the number.

The problem with Fosfomycin is that there isn't a lot of evidence to support it's use in complicated infections. According to this article there have been case reports of it's use in complicated infections: http://journals.lww.com/infectdis/Fulltext/2001/06000/Fosfomycin__A_Review_.4.aspx


But it would only be used as a last resort until there is more evidence. It is not mentioned in the IDSA guidelines for treatment of a complicated infection.

Fair enough - I'd point you to the IV fosfomycin data from Europe. Granted those aren't UTIs, but I think that sepsis is more difficult to treat than UTIs. There are also these more recent reviews that are worth reading - data for oral fosfomycin goes well beyond case reports (the paper you reference is from 12 years ago now): http://jac.oxfordjournals.org/content/65/suppl_3/iii25.full and http://www.ncbi.nlm.nih.gov/pubmed/20129148 or http://aac.asm.org/content/early/2012/08/21/AAC.00402-12.abstract.

So I'm still left wondering why Nitrofurantoin is not used in complicated UTI's. It is not effective against Psuedomonas or Enterococcus faecium, which you have to worry about with complicated infections. Although if a patient has Enterococcus faecium, you're left with very little choices :S

Thanks for your help 🙂

Since when is nitrofurantoin not active against E. faecium? (http://aac.asm.org/content/45/1/324.full)...I'll agree with Pseudomonas, though. And remember, if we're dealing with simple community-acquired UTIs, Pseudomonas is way far down on the list of potential organisms. With the exception of cipro, are any of the other drugs you mentioned active against Pseud?

Sorry if this comes across harsh, but remember that it's not just your reputation on the line, it's pharmacists in general. I always hear about it when the physicians I work with get called by an outpatient pharmacist on something like this and don't know what they're talking about. I've built up enough trust where we joke about it and that's the end, but it took me a long time to get there. If you're going to make a recommendation, know your stuff before you do it.

And one last point - these papers are not hard to find. Took me about 2 seconds worth of Googling - you don't need institutional access to get good information.

 

[All4MyDaughter]

I always hear about it when the physicians I work with get called by an outpatient pharmacist on something like this and don't know what they're talking about. I've built up enough trust where we joke about it and that's the end, but it took me a long time to get there. If you're going to make a recommendation, know your stuff before you do it.

A long time? Out of school < 2 years and already mocking other pharmacists with the physicians? I'm sure you don't mean it that way, but it comes off as pretty smug. 🙁

I teach my students the Macrobid contraindication. Do I tell them that it can never be used? No. But I am not sure that they will go wrong by following the information in the manufacturers' labeling. They will often have to make do with the information that is most readily available + their own clinical judgement. Most of us "outpatient pharmacists" (and many outpatient prescribers) don't have time to consult primary literature when trying to make clinical decisions. The world outside of academic medical centers is quite different than that found in teaching institutions.

 

[thephoenician88]

I think you're all over thinking this scenario, especially from an outpatient basis. Clearly the MD is just trying to avoid any warfarin issues, I would just call MD about her renal function. Micromedex states nitro shouldn't be used in <60 but mentions it could be >30. I would just discuss with MD, and if he says she'll be fine then we'll go with it.

The last thing i would do in a retail position would be to call up md, tell him it's contraindicated and i'm assuming she has poor renal, and then offer something like cipro or augmentin.

Also, dog on motorcycle, if you see this daily and work with this daily, then of course you would be well versed in exactly what happens. Pharmacists on the other end should be able to handle it as it comes, but most retail pharmacists don't have time to pull a literature search during the busiest time of the day to try to justify MD.

 

[Praziquantel86]

A long time? Out of school < 2 years and already mocking other pharmacists with the physicians? I'm sure you don't mean it that way, but it comes off as pretty smug. 🙁

I teach my students the Macrobid contraindication. Do I tell them that it can never be used? No. But I am not sure that they will go wrong by following the information in the manufacturers' labeling. They will often have to make do with the information that is most readily available + their own clinical judgement. Most of us "outpatient pharmacists" (and many outpatient prescribers) don't have time to consult primary literature when trying to make clinical decisions. The world outside of academic medical centers is quite different than that found in teaching institutions.

I'm not mocking pharmacists, simply pointing out what happens when recommendations are made with incomplete information. Worst case scenario, the patient is harmed. And this goes for inpatient pharmacists as well - if you don't know enough about the clinical scenario to gather all the information necessary to make a recommendation, the recommendation should not be made. One of the staff pharmacists I work with recommended a full dose of cefepime for a patient on dialysis, without realizing that the creatinine was low because the patient had just been dialyzed. We were called by a retail pharmacist who refused to dispense a prescription for 2 days of Tamiflu (because it's a five day treatment course) despite the prescription saying that the patient had already received 3 days worth of treatment in the hospital.

I'm not saying that there is an inherent difference in the knowledge base of outpatient pharmacists, but I am saying that there is a difference between those who are willing to make a recommendation on incomplete information versus those who are not. And yes, it's taken me 7 months to get to the point where I'm completely trusted by the physicians I work with (this is a private hospital, not an academic center) - I'd consider that a long time.

I think you're all over thinking this scenario, especially from an outpatient basis. Clearly the MD is just trying to avoid any warfarin issues, I would just call MD about her renal function. Micromedex states nitro shouldn't be used in <60 but mentions it could be >30. I would just discuss with MD, and if he says she'll be fine then we'll go with it.

The last thing i would do in a retail position would be to call up md, tell him it's contraindicated and i'm assuming she has poor renal, and then offer something like cipro or augmentin.

Also, dog on motorcycle, if you see this daily and work with this daily, then of course you would be well versed in exactly what happens. Pharmacists on the other end should be able to handle it as it comes, but most retail pharmacists don't have time to pull a literature search during the busiest time of the day to try to justify MD.

That's my point - if you don't have the time to fully understand the implications of the recommendations that are being made, then those recommendations should not be made. That just seems to be good practice. What happens if they ask the question "Why?" and you have no response beyond that's what I was told? Your credibility goes out the window. I worked retail for 6 years, 4 as an intern at very busy stores - I've never been a pharmacist in the retail setting, but I have a good idea of what the time constraints are. If it's worth calling about, it's worth spending two minutes on Google to justify yourself.

 

[naseuy]

We were called by a retail pharmacist who refused to dispense a prescription for 2 days of Tamiflu (because it's a five day treatment course) despite the prescription saying that the patient had already received 3 days worth of treatment in the hospital.

This is probably more of an issue where the pharmacist doesn't want an open box of Tamiflu sitting around waiting to expire than a clinical objection....

 

[All4MyDaughter]

This is probably more of an issue where the pharmacist doesn't want an open box of Tamiflu sitting around waiting to expire than a clinical objection....

That's what I was thinking. I would not be able to sell the other three days worth, most likely. I would also be hesitant to break the package.

 

[Praziquantel86]

This is probably more of an issue where the pharmacist doesn't want an open box of Tamiflu sitting around waiting to expire than a clinical objection....

I'm sure it was - but instead is was framed as a bogus clinical objection, and perpetuated the physician's belief that pharmacists don't know what they're talking about. I wouldn't want it sitting on my shelf either, and there's nothing wrong with calling and mentioning that.

 

[All4MyDaughter]

I'm sure it was - but instead is was framed as a bogus clinical objection, and perpetuated the physician's belief that pharmacists don't know what they're talking about. I wouldn't want it sitting on my shelf either, and there's nothing wrong with calling and mentioning that.

Did you actually take the call from the retail pharmacist yourself?

 

[Praziquantel86]

Did you actually take the call from the retail pharmacist yourself?

No, but I was sitting in the room with the physician when she did. I have taken calls from pharmacists about recommendations that I've made, however.

 

[All4MyDaughter]

No, but I was sitting in the room with the physician when she did. I have taken calls from pharmacists about recommendations that I've made, however.

What was the outcome?

 

[Praziquantel86]

What was the outcome?

She ended up calling the Rx into a different store that would dispense the appropriate amount.

 

[All4MyDaughter]

She ended up calling the Rx into a different store that would dispense the appropriate amount.

Yeah, confirms my suspicion that it was a business objection, not a clinical one. A third grader understands 5 - 3 = 2. I suspect you might have heard an embellished version of the anecdote, especially if joking about knowledge-challenged pharmacists is the norm at your place. Just no way in hell the retail pharmacist didn't understand.

 

[confettiflyer]

Pt will get whatever abx and will be instructed to check-in with their coumadin clinic at shorter intervals, done. Working clinic I had no say in abx since that was in their primary care office, and depending on the timing of the visit I'd empirically reduce dose based on pt's history.

I'd reduce f/u time to 1 week intervals while on abx and I don't get too excited if the INR shoots to 3-4 unless I have a narrow goal of 2-2.5 for my sensitive pt's.

I'll even augment with diet if the pt is agreeable.

Often a 4-week interval pt shows up and says they had a 7 day course of abx that ended 3-4 days ago...yah can't do much about that. So retail pharms - ask your pt's when their next CC apt is.

 

[njac]

Cephalexin. Boom. Done.

 

[rxlea]

Cephalexin. Boom. Done.

Like.

 

[pinipig523]

At our hospital, our antibiograms showed that cipro had more resistance than augmentin. So your patient can potentially be placed on Augmentin 875mg po bid for 10 days.