78 y/o female with UTI/vesico-vaginal fistula growing enterococcus x 2 cultures; susceptible to amp, nitrofurantoin and vanco. Pt is allergic to penicillin, nitrofurantoin and sulfa. Pt was started on Vanco 1 g IV q 12h – level prior to 3rd dose with orders for pharmacy to adjust dose. eGFR= 71 mL/min; Scr= 69.
According to susceptibilities, vanco is the only option due to allergies, but I’m not sure it’s the best. Do you know of any other abx options that are good for enterococcus in this scenario?
Great case. Thanks for the question.
I tried to go through her profile to better characterize this fistula but I couldn’t find any imaging report or note that really describes the extent of her problem. I believe that currently has extensive metastatic ovarian cancer, had debulking surgery and this is a sequelae of the procedure. She also underwent left-sided stent placement as a result of obstruction, which was changed sometime in January . As you may already know, the treatment for this is surgery. If the fistula is very small, sometimes catheter insertion can let it heal up, but usually this is not sufficient. No antibiotic is going to fix this permanently. I gather she is here to be considered for surgical repair as these fistulas are a significant problem for patient’s QoL, even if she is palliative.
In general, a vesico-vagnial fistula is a tract that communicates between the bladder and the vaginal tract. The bugs that can be found there are the same ones that cause UTIs. She happens to have small amounts of enterococcus in the urine, and you can expect that those are also leaking into the vagina. Although this appears to be a “bad” problem for someone with complex anatomy/foreign material, a lot of these people will have bugs in the urine. If we keep looking for them, we will find them. Unless she is going for urogenital surgery, I would recommend that you DO NOT treat her unless she has symptoms. I doubt that she does – I didn’t see fever, leukocytosis or any other SIRS features. She likely has a catheter in and does not have urinary symptoms. I would also stop culturing her urine as it will undoubtedly be positive.
One indication for treatment, however, is surgery. This would require pre-operative treatment, which means just before surgery. You can give her vanco until she goes for surgery, and that’ it. It would be ideal to stop the vanco now, and give it to her just the day of her surgery without all the TDM, but this may be challenging if she’s waiting for an opening. Hopefully the surgery will be scheduled soon, and you can just give her 1-2 days of vanco. If she’ll be on it over the weekend, you can check a level if you want, but don’t chase it unless it’s significantly below 10 or over 20. If she does not go for surgery, stop the vanco immediately and do not do any more urine testing unless she has symptoms.
If she does develop an infection from this source, she needs more work-up. I understand that the fistula is number one on the list as a cause, but the MRP would in that case need to rule out the involvement of the left kidney and the stent. These stents can be a significant source of infections. For antibiotic treatment, should she become symptomatic, we would use the same drugs as we would for pylo or a UTI. These drugs need to get into the bladder well and be effective against these bacteria, and this can include oral medication such as nitrofurantoin. If there is stent/kidney involvement, then nitrofurantoin cannot be used. In this unlikely scenario, I would really verify these allergies and explain to the patient what we’re dealing with, but besides what you see in the sensitivities, there aren’t any other options besides weirdo/inappropriate drugs like ceftaroline, linezolid, dapto etc.