Abx question

[thegenius]

I've got an ID question, however it doesn't appear there is a specific ID subforum. So hopefully this forum is OK.

I treated a patient in the ED for a complicated UTI / early pyelonephritis. She ended up being stable, not septic, gave one dose of Rocephin IV and discharged her with antibiotics. cefadroxil 500 mg PO BID x7 days.

Her urine culture returned a few days later
100,000 cfu/ml Pseudomonas aeruginosa
with pan-sensitivity

Think the cefadroxil will be OK? Or should she be changed to something else like a fluoroquinolone or cefpodoxime?
Thanks.

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[VA Hopeful Dr]

Pretty sure it needs to be changed. Don't use cefpodoxime.

 

[Splenda88]

I don't think cefpodoxime provides pseudomonas coverage... I think a fluoquinolone (ciprofloxacin) is ok in that instance.

 

[liquidlarotrectinib]

Pseudomonas can be sensitive to cefadroxil. But it is not an appropriate empiric choice given most strains of Pseudomonas will be resistant to it. If you don't have an assay that says it is sensitive to cefadroxil, which you don't, you need to switch antibiotics. Cipro or Levofloxacin seem like the most appropriate choices for outpatient management.

 

[deleted1013332]

The FDA data sheet says that it has no activity against Pseudomonas species.

 

[thegenius]

Why not use cefpodoxime? It’s a third generation cephalosporin like ceftaz above. I was under the general impression that drugs within the same classes have similar antibio effects (although may not be 100% similar).

But my PO choices are minimal though. Looks like fluoroquinolones. There aren’t too many 3rd or 4th gen cephalosporins available in PO form.

 

[VA Hopeful Dr]

Why not use cefpodoxime? It’s a third generation cephalosporin like ceftaz above. I was under the general impression that drugs within the same classes have similar antibio effects (although may not be 100% similar).

But my PO choices are minimal though. Looks like fluoroquinolones. There aren’t too many 3rd or 4th gen cephalosporins available in PO form.

Generally you're right, but this is a special case. Only 1 3rd gen cephalosporin has activity against pseudomonas these days, and that's ceftaz as you mentioned (its weird, but it is what it is).

Basically the only PO meds with any activity against pseudomonas are levaquin and cipro. Avelox does not so stay clear of that in this patient.

 

[mszzeta]

I've got an ID question, however it doesn't appear there is a specific ID subforum. So hopefully this forum is OK.

I treated a patient in the ED for a complicated UTI / early pyelonephritis. She ended up being stable, not septic, gave one dose of Rocephin IV and discharged her with antibiotics. cefadroxil 500 mg PO BID x7 days.

Her urine culture returned a few days later
100,000 cfu/ml Pseudomonas aeruginosa
with pan-sensitivity
View attachment 283224


Think the cefadroxil will be OK? Or should she be changed to something else like a fluoroquinolone or cefpodoxime?
Thanks.

I don't think it is appropriate to use first-generation cephalosporins to treat UTI in modern era, let alone pseudomonoas!

The choice of abx in treating UTI depends on local bacteriogram. And cefpodoxime or other 3rd generation cephalosporins is a common option for places with high resistant rate to both bactrim and fluoroquinolone

 

[thegenius]

At one of my hospitals we use cephalexin all the time for UTI. it's approved in the literature as well. 500 mg BID x7 days.
If you have pyelo, my ID consult says cephalexin is fine as long as you do 500 mg QID x7-10 days.

At the other hospital I work at (Kaiser), they instead use cefadroxil for all the same indications as cephalexin. cefadroxil is nice as it's 500 mg PO BID x7-10 days. It's never QID dosing as far as I can tell, even for pyelo. Kaiser probably has some sort of deal with the manufacturer of cefadroxil making it cheap as I sometimes prescribe it at my initial hospital and I get calls from the pharmacist that it's not on formulary for CA Medicaid patients.

I don't think it is appropriate to use first-generation cephalosporins to treat UTI in modern era, let alone pseudomonoas!

Recall that I treated her empirically and got the urine culture results back a few days later.

 

[IMrad]

Call the patient. Tell them to stop taking the abx they were prescribed. And write a 5-7 day course of cipro.

 

[thegenius]

Call the patient. Tell them to stop taking the abx they were prescribed. And write a 5-7 day course of cipro.

Yup! just did it.

 

[aafisahar]

cefpod would have been a fine choice. The real worry is MDR PsA but your strain is pan-sensitive. There's nothing special about PsA and antibiotics other than having a propensity for more MDR strains.

In contrast, enterococcus is always resistant to cephalosporins even if it's not reported that way on the sensitivities. That's where Rx'ing a penicillin makes sense.

FWIW, I discharged most patients on either amox or cefpod when I was a resident.

 

[VA Hopeful Dr]

I don't think it is appropriate to use first-generation cephalosporins to treat UTI in modern era, let alone pseudomonoas!

Explain why that is, because e coli is still 90% sensitive to cefazolin in my area.

 

[mszzeta]

Explain why that is, because e coli is still 90% sensitive to cefazolin in my area.

High resistance rate. For example, you can look at this review article

Management of uncomplicated urinary tract infections

www.ncbi.nlm.nih.gov

It is written by UCSF pharmacist

 

[mszzeta]

Explain why that is, because e coli is still 90% sensitive to cefazolin in my area.

I do believe local bacteriogram is also important so it may make sense to use these agents in your area, though it may not be generalizable to other US hospitals

 

[VA Hopeful Dr]

High resistance rate. For example, you can look at this review article

Management of uncomplicated urinary tract infections

www.ncbi.nlm.nih.gov

It is written by UCSF pharmacist

That article is 17 years old.

Why not use this one instead it's 10 years newer: International Clinical Practice Guidelines for the Treatment of Acute Uncomplicated Cystitis and Pyelonephritis in Women: A 2010 Update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases

 

[xoggyux]

While guidelines and bacteriogram are helpful for empiric it is not helpful on selecting the antibiotic once the sensitivities back the management should be straightforward choosing whatever antibiotic the organism is sensitive to with the best tolerance profile.

In theory, I think the proper thing to do would be to call the patient and re-assess if symptoms are still present. Spontaneous resolution of infections do occur and some antibiotics that are traditionally reported as "intermediate" or resistant can end up having partial activity against the organism in vivo in specific tissues because of the volume of distribution of medications. I say this to emphasize that we treat people and not tests.

The situation is tricky and I have been in the same position a few times, sometimes I go ahead and prescribe the second antibiotic, sometimes I hold back. I make the decision based on a full disclosure discussion with a patient with risk/benefit just as the first time I gave antibiotics and document it as such. Things that bias me towards giving antibiotics anyway: Bad infections, poor follow up of a patient with PCP once discharge, low confidence on the patient. If the original encounter documented anything regarding possible pyelonephritis I am afraid I would have also done the new antibiotic prescription as such and I admit it is not so much a medical decision but a cover your ass kind of decision. C'est la vie

 

[mszzeta]

That article is 17 years old.

Why not use this one instead it's 10 years newer: International Clinical Practice Guidelines for the Treatment of Acute Uncomplicated Cystitis and Pyelonephritis in Women: A 2010 Update by the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases

"β-Lactam agents, including amoxicillin-clavulanate, cefdinir, cefaclor, and cefpodoxime-proxetil, in 3–7-day regimens are appropriate choices for therapy when other recommended agents cannot be used (B-I). Other β-lactams, such as cephalexin, are less well studied but may also be appropriate in certain settings "

cefdinir and cefpodoxime are third generation. cefaclor is 2nd generation .And cephalexin is first generation. I think they are still with significant reservations of first generation cephalosporins

 

[VA Hopeful Dr]

"β-Lactam agents, including amoxicillin-clavulanate, cefdinir, cefaclor, and cefpodoxime-proxetil, in 3–7-day regimens are appropriate choices for therapy when other recommended agents cannot be used (B-I). Other β-lactams, such as cephalexin, are less well studied but may also be appropriate in certain settings "

cefdinir and cefpodoxime are third generation. cefaclor is 2nd generation .And cephalexin is first generation. I think they are still with significant reservations of first generation cephalosporins

E. Coli resistance rates in my area are 25% for bactrim, 20% for Cipro/levaquin.

My approach is for cystitis, everybody gets macrobid (3% e coli resistance) unless allergic or CKD, then cephalexin if no recent antibiotics ceftin if they have. Pyelo gets rocephin x1 then omnicef.

I've tried to use fosfomycin but can't get insurance to cover it.

This tracks with the evidence/recommendations quite well.