Antibiotics and weight gain????

Hi everyone i was prescribed antibiotics for an infection in my leg. i have been on  (Doxycycline hyclate and Bactrim ds) now since this past thursday january 12th so 6 days in that amount of time i have gained steady everyday i have gained a total of 9.7 pounds. Has anyone else had this happen with antibiotics I am guessing this is why I am gaining I have not changed anything else in my routine.I need to figure this out because as everyone knows 9.7 pounds is not easy to lose..... anything anyone can tell me about this would be helpful I am so upset about this...thank you in advance for any information you can give me. (as a side note i plan to go on full liquids today)

 I would call my doctor. Bactrim can affect the kidneys, and you could be retaining fluid. Or any other number of things. 

I've never seen 10 pounds weight gain with Bactrim or Doxycycline, but sodium/water is the only thing that makes since on that short of term. Its possible that the infection rather than the medication is lowering kidney function.
(Assuming you haven't eaten more)

If you are only going to be on them for a short while then the water should go away with the medication and/or the infection. I agree with the above though that since it seems to be an abnormal amount of weight gain, maybe your doctor should check your kidney function (BUN and Creat along with a Chem 7 should be enough - maybe a Urine for protein)

thank you for your reponses i took your advice and called my family doctor and my surgeon and they took me off the antibiotic and started me on probiotics and are going to repeat bloodwork i am having problems with my electrolytes and low potassium thank you again for your responses i will let you know how i am doing