Suggest Dosage For Cephalexin While Suffering From Recurrent UTI

Posted on Wed, 6 Sep 2017

Question: I'm a c-6 quadriplegic, 25 years post-injury. I do an intermittent self catheterization 4x daily. I've had a long history of chronic UTI's (some being MRSA and VRE infections). Recently, a Urologist recommended I start taking a maintenance course of Keflex (Cephalexin) 500mg 3x a day - Every other day (that's a total of 1500mg one day on then one day off). I've been on this regimen for 5 months with no recurrent UTI's. It's wonderful to be infection free but no other physician I've spoken too has heard of this regimen. While it's hard to argue with success, I'd like to know why it works and how it works? Could this infection-free period be a coincidence? Lastly, am I at risk of developing an antibiotic resistance?
Any light you could shed on this would be greatly appreciated. Thank you in advance.

Answered by Dr. Panagiotis Zografakis (1 hour later)

Brief Answer:
not heard of it...

Detailed Answer:
Hello,

although cephalexin is one valid option for prophylaxis, this dosage is unknown to me. What Sanford's guide to antimicrobial treatment recommends is cephalexin (as one of possible options) 250mg per day. Prophylactic treatment is controversial as there is not enough adequately documented evidence from clinical studies. Perhaps choosing other options may worth a try, like cranberries' extract for example which has proven some efficacy in prevention, but no efficacy in treatment. If cranberries are not sufficient to reduce the number of urinary tract infections (UTI) then using drugs can be considered, starting from low dose antibiotics like half a double strength tablet of TMP-SMZ per day (instead of one every 12 hours which is the standard dose for treatment) or even cephalexin 250mg per day.

One thing to consider is to review the catheterization procedure so that everything is done as sterile as possible and without injury. You can talk with the urologist about the procedure because infections may have to do with improper technique.

I can't say whether the infection free period was a coincidence or not. Taking antibiotics is supposed to eliminate the pathogens or at least contain them so that the body can defend itself more effectively. Antibiotic resistance is a sure thing after prolonged antibiotic exposure...

So in conclusion, although there isn't strong evidence in favor of any prophylaxis option, the recommended dosage for recurrent UTI is 250mg of cephalexin once per day. Antibiotic resistance is almost certain after prolonged use.

I hope it helps!
Kind Regards!

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Panagiotis Zografakis (22 hours later)

Is it possible that an infection exists but the antibiotics in my system mask the results on a dip stick and a bacteria culture?
Thank you... XXXXXXX

Answered by Dr. Panagiotis Zografakis (18 minutes later)

Brief Answer:
Yes and no... Please read the full answer

Detailed Answer:
Although it is a fact that antibiotic treatment may hide bacteria in culture results it is less likely to do so when the bacteria are resistant. Otherwise the antibiotic should prevent or treat the infection.

In patients with sensory deficits it is hard to diagnose real uti because symptoms play a big role in the diagnostic process. The urinalysis and/or cultures may be positive but it could be an asymptomatic bacteriuria. Another thing to consider is that patients who undergo urological interventions like catheterization may develop a real uti if they have bacteriuria.

I hope this makes things more clear.
Kind Regards!

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Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar