Trimethoprim ; worried about side effects

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I have most of the posts related to this medication and am on high alert of  the side effects.  Following attending Urgent Care I was prescribed Trimethoprim a  5 day x2 daily course. The first 2 tablets 1) taken in the afternoon and 2) at night; I woke with cramp in my abominal region, feeling shakey and so scared and took paracetamol to help with the pain. Not what I had expected!!

So reading again all the side-effects sypmtoms and posts I really would like to know how many of the outlined side effects people have had. I am so worried to continue on with the medication vs clearing UTI.

Particularly - weight loss as I have been experiencing weight loss I dont want to lose more or indeed develop loss of appetite.

Itching and rash (slight itching has started), headache, (first evening of taking it). But the side effects listed are much more as well as others which have been experienced by the posts that sound so horrendous.

itching and rash




stomach upset,

loss of appetite,

changes in taste,


skin sensitivity to sunlight,

swollen tongue, and


Whilst feeling unwell and needing all the support and recovery possible we dont need medications that are supposed to one thing causing further problems for us.


0 likes, 4 replies


4 Replies

  • Posted

    Hi Elaine,

    I wouldn't take this medication again personally unless I really really had to.... my issue turned out to be a deficiency to caffeine after my first medication did clear up the UTI. Trimethoprim was the second of three medications I took.

    If I can give you any advice it would be to complete the course, but take a few weeks off to rest in bed with few distractions. I took 3 months to get over the side effects and I think If I'd been able to take some time off work and relax my recovery would have been much quicker.

    If diarrhoea is an issue and contributing to the weight loss, simply take imodium as directed in the leaflet, but speak to your doctor first if still on any other meds. I put up with the diarrhoea for ages and finally taking something for it, did stop it.

    I also got really weird sensations in my head, a numbness, it was awful, I felt like my IQ dropped by two thirds.

    I hope you don't suffer too much, get better soon,



    • Posted

      Hi Graham

      Many thanks for your reply sharing your experience and advice on this medication. I think your right that these meds from what I have also read are synthentic and ultimately not nice in side effects. I relate to the having sensations behind my left ear towards my back of my head feeling numb that in its self is scary as your trying to deal with other things going on.

      May I ask how long was your course of medication for (mine is fo 5 days) and more specifically the side effects had please it sounds that you had chronic side-effects ???

      I've already had week off from work this week and will be off for next week also I really hope I dont need to take anymore time off (I work in the NHS) in fear of dealing with subsequent side effects.

      Have you made a full recovery from the side effects (hope you have been able too).

      Best wishes


    • Posted

      Hi Elaine,

      I was on it for 7 days, i visited the out of hours GP after the third day who told me to keep taking it if i could stand the side effects.

      During my three month suffering i went to my GP a lot who disagreed this medication had made me feel the way i was but this forum proves it had to be the Trimethoprim.

      Im a lot better now thank-you. Not had any further issues and keeping away from the caffeine. I found it really scary because i wasn't sure what was causing my issues. Just know that the side effects will disappear, and i think you will cope with it better than i did in that knowledge. If the UTI issue persists following a week off the meds go back to your GP smile

      Best Wishes,


  • Posted

    I have just been perscribed a 3 month course of this medication for recurrent infections and am afraid to take it now after reading people's experiences here.


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