What is the different action or benefits of cephalexin and cotrimoxazole in prophylaxis treatment of U.T.I?

I have 7 month girl who recived injection antibiotic in hospital folowing urinary tract infection and pyelonephritis for 10 days . her first doctor belives that cotromoxazole is the best medication for her prophylaxy treatment for 3 month .but her second doctor says that cephalexin is safer to some extent .which one is really best one ? which one has more serious side efect ? i asked this becaus my doughter is more susceptible for ( entherobacter ) infection while taking cephalexin .can i change it with cotrimoxazole ?
she was in hospital for E-Coli infection

I am just taking a shot at this. You state that your daughter has e-coli with pyelonephritis . I am going under the assumption that she had haemolytic uraemic syndrome caused by enterohaemorrhagic E.coli infection.

There is no single antibiotic therapy is better than the other for your daughter's case. Most antibiotics are nephrotoxic (aka damaging to the kidneys) and the side effects depends on the individual taking it.

There are some risks involving cotrimoxazole for newborns which includes brain damage. I am not too sure of the effects it will have on a 7 month old.

Cephalexin is a broad spectrum antibiotic which has been around for a while. The issue with it is not so much with newborns. Rather that it increases the risk of bacterial overgrowth and intestinal infections because it wipes out the susceptible bacterial but not the non susceptible ones such as Clostridium difficile .It is a drug which has been classified as a lowest risk drug to pregnant mothers in terms of foetus malformations and miscarriages, when compared to Cotrimoxazole which poses a higher risk to pregnant mothers.

If it is just a prophylactic dose - frankly one can assume that cephalexin is more likely to pose less of a problem to your 7 month old daughter. However you have to take precautions such as going back to your doctor if she starts having diarrhea. That is just my opinion.

When in doubt between 2 doctors, get an opinion of a third. And for your case, the third doctor should be a trained paediatrician (a doctor specialising in babies/children's medical care) - paediatricians will know what drug they can give to a baby and explain to you in concise terms what the risks involve.

Disclaimer : the advice I provide is not a medical solution to your problem.

Co-trimoxazole is an antibiotic combination of trimethoprim and sulfamethoxazole.

Cephalexin is in a group of drugs called cephalosporin antibiotics.

They are both used to treat infections caused by bacteria, including upper respiratory infections, ear infections, skin infections, and urinary tract infections.

Some studies indicate that cotrimoxazole appears to be superior to cephalexin in the management of acute urinary infections. Both have side effects and with more severe ones usually associated with cotrimoxazole. If she does not have these side effects, however if she is tolerating it well, it is reasonable to stick with it.

Make sure that if she gets a second one more UTI's that she is properly investigated as recurrent UTI's can lead to kidney damage.

Speak to her doctor if you are worried about side effects, you will not get better information from anyone on Answers than you will from her doctor who knows what's going on.

Good luck.