I was just prescribed 500 mg of cephalexin, as a precaution. Since I am having a surgery soon. It seems like I have to pee literally every 5 seconds. Is this a common side affect, or does it mean I'm allergic? I started taking it yesterday after noon, and am supposed to take it 3 times a day. I have taken 4 so far.
Does cephalexin cause you urinate more often?
Question posted by Adrein26 on 2 June 2011
Last updated on 30 March 2025 (3 weeks ago) by duckieruns
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18 Answers
Yes it mostly certainly does. I have been urinating like crazy. I was prescribed 500 mg 4 times a day for 10 days. I was prescribed because of a UTI… I thought the medicine was not working since im still frequently peeing. Then I thought the medicine was not working and found this thread.
Even with a little bit of water or depending on what you’re eating you will still urinate- thank god I don’t have pain but it is a little nerve racking having to go. I still have 4 more days on this. I was told to drink more water to flush out the UTI and for the medicine to work but this is crazy.
Yes, I was on 500 mg of Cephalexin twice a day for 6 days after GreenLaser TURP. After the catheter was removed I was able to urinate successfully. I was Peeing every 1/2 Hour to an Hour days and up every hour at Night. When I stopped the Cephalexin I thought something was wrong. I started Peeing maybe 5 or 6 times a day and a couple times at night. Actually scared me thinking the operation was reverting back. Then I found this Discussion and it all made sense.
Yes it does. At first I thought it was because I was drinking a lot of water, however I noticed that even if I take a small sip I have to run to the bathroom. I've only been on it for 2 days 4 times a day 500mg and I'm glad I don't have anything to do because I have to pee alot.
OMG yes. It must. I got on this medication because I thought I might have a mild UTI although the tests were negative. I did not have the type of frequency prior to starting this medication. It's really distressing when you have the urge to pee every 15-30 minutes but no pee to let out (dehydrated). I've learned to drink a serious amount of water so that there's always something to let out and that cuts down on irritation or upset. Tbh it really has been stressing. I can't sleep, I can't relax. I still have two more days on this pill (500mg/3x day) so I'm praying it resolves once its out of my system. Seeing this thread has made me feel a lot better.
Yes, I noticed the change within the first 2 days of taking 500mg 4 times a day. I first experienced a sudden and surprising 2-3 days of diarrhea (once a day). Soon following I had a strong urge to urinate at least 3 times a day that lasted more than a week (I still have urges 10 days later, after stopping taking the antibiotic) The urges never woke me up in the middle of the night, but were strongest very early (between 5-6 am) which is when I usually rise. I also looked for answers at other different medical websites but Drugs.com was the only one that confirmed (from actual users) frequent urination as a side effect of cephalexin ("Keflex" in the US). I'm inclined to believe that it must indeed be a related side effect to taking the drug since I did not have any diarrhea or urinating urges prior to using it.
yes it most definitely does. I had a (broken) thumb injury at work a couple months back. I was prescribed some to take 3 times a day. After the first day I couldn't stay out of the restroom and at times barely made it. But overall it works.
Yes I was prescribed this medication 1 day ago due to a really bad uti that went to my kidneys. After 30 minutes of taking this medication I was rushing to the bathroom. After that I have been going every 30-40 minutes and barley making it to the bathroom in time. This is without barely drinking any fluids.
I am having the same issue. I have been on this for 7 days 500mg twice a day. Started with a UTI and I have been going every 45 mins for days. What the heck?!
Yes, it absolutely does. I read all I could about this medication before taking it for my UTI and excessive urination is not listed as a side effect. I started to realize that I was urinating a lot more than normal and in looking up the prevalence of this as a side effect, drugs.com is the *only* site where I have seen others report to have the same issues. I’m 4 days in and experiencing mild diarrhea. Had abdominal discomfort on the first 2 days and, for the past 2 days (maybe more), frequent peeing. Urine is clear and odorless. There is no pain or burning sensation when voiding. I feel like a sieve! As soon as I drink water, it seems I need to release it.
Hello, Did it go away after you finished the medication?
I thought I was crazy. I pee alot anyways, but this wakes me up constantly. I almost peed the bed the other night.
This is definitely a side effect. It was making me pee so much and actually making my urethra hurt, I went back to the doctor to ask if I could stop taking it because the peeing was driving me crazy. I was also experiencing stinging pain with the peeing. I've been off it for 24 hours now and am still experiencing this horrible side effect.
I was prescribed cephalexin at 500 mg. 3 times daily for a UTI. By the 2nd night, I was wetting the bed. I kid you not, I have never had to pee so much with a UTI in my life. I thought maybe I had something bad wrong and even called an online dr. She told me to go to my regular general practitioner... I'm reading about all the other people that have had the same side affects and now my anxieties are gone. The only thing is now I need diapers for the rest of my treatment. This is absolutely crazy! Thanks to everyone that has answered this question. Daytime is best because i know how long i can hold off..but night time waking and needing to go in a split second... no way.
I have been prescribed 250mg at bedtime for unexplained recurrent UTI in pregnancy as a daily prophylaxis until I give
birth. YES this med does cause frequent urination and all of your answers have validated the effect I am feeling as well- so thank you for posting. Yes I am
battling UTI which does cause frequent urination but I have noticed that within 10 minutes or so of taking this, I am having to go a lot more within certain time frames, than I do in the day when I am not on it- and drinking more water. Like one poster mentioned, several times per hour, and can last 5-6 hours so imagine needing to sleep but waking up
constantly to urinate. Very inconvenient and uncomfortable. Good luck to everyone.
I was prescribed this 4 days ago for a case of strep throat , I am also having the same side effect . I normally go about 2 or 3 times a day , now I'm going about 2 or 3 times every hr .cant wait to be off this
Oh my god. It was prescribed to my three year old. She’s been crying each night. Score bed begging me to find diapers and to let her go pee on a potty (where she will sit endlessly). I went to a doctor today with this issue and they had no clue what’s up. This medication is ridiculous- my little one is devastated. I have been crying each night trying to figure out what it is. Wonder who I should contact so this issue can be added as a side effect.
Related topics
Further information
- Cephalexin uses and safety info
- Cephalexin prescribing info & package insert (for Health Professionals)
- Side effects of Cephalexin (detailed)
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