Trimethoprim for VUR

[geordiepharm1]

Following a routine test for a urine infection at 5 months old my Son was diagnosed with Vesico-ureteric reflux.

They prescribed 50mg/5ml trimethoptim 2.0ml to be taken at night. (To prevent any possible infections from occuring).
When he got to about 1 year old they increased the dose to 2.5ml due to his increased weight/size. (They explained at the hospital that the dose would need to be increased gradually as he grows).

However, upon speaking with my GP he said (quite dismissively) that the dose does not need to be increased any further, despite being on the same dosage since he was 12 months (he is now 2yrs 9 mnths). As you can imagine he is now a lot bigger than he was at 1. Does this sound right?

[Rafael]

check how trimethoprim is distributed(fatty tissues or muscles) and metabolised in the body and work out the rest.

[geordiepharm1]

Just to clarify, I am currently posting as a member of the public with a drug inquiry.

Sorry if my screen name has caused any confusion. I am starting MPharm this September.

[Nik]

According to BNF-C, dose is worked out on mg/kg basis, so as your son grows older, the dose would presumably increase. For prophylaxis of UTI's, the recommended dose in children (1 month - 12yrs) is 2mg/kg once daily at night (max 100mg). Dosages and indications of drugs for children can be found in the British National Formulary (BNF) for children (currently 2008), which along with the BNF, will become important reference books throughout your degree course.

[johnep]

Talk to your pharmacist. This would be what is known as a Medicines Use Review.
johnep

[geordiepharm1]

Well from my working out as he is now 14.3kg he should be on around 2.9ml. Don't know if I have worked it out right or if it would make much difference to 2.5ml...

I'd better leave it to the experts for now and visit my pharmacist!

Thank for the advice guys.