trimethoprim prophylactically for bladder reflux

[Clarella]

Hello,

My son has bladder reflux and is on trimethoprim. I've been going round and round regarding dosage, weight linked.

Now in a situation where I'm wondering if he has a slight uti and cursing myself about the dosing again!

Couple of weeks a GP wrote out a weight list with appropriate doses; to the ml. He was 12.4 when we measured him so she says 2.5 is still appropriate however he's packed out in a fortnight and now 12.6 so should be on more 2.6 as she says round up to next kg, round down if 12.4.

When he was first put on it at the hospital he was on quite a bit more than according to weight. I sort of feel it should be 3 ml (but obv don't want to give too much antibiotics if needed!) and the pharmacist seemed to indicate he'd do that.

But no one will give a clear answer?!

Does anyone have a child on trimethoprim prophylactically? How have you been dosing?

My DS was on this for over 12m as a baby due to unexplained urinary infections when a few weeks old and sleepiness...
No-one seemed too fussed about varying the dosage level then but really it is for your GP to decide so explain your concern and then do what s/he advises and try not to worry! They do keep them on a low dose for quite a while.

My daughter was on it for 5 years. Every time she had a paediatrician or urology appt they would weigh her, tell me what dose to put her on, and tell us what to increase it to when she reached the next weight milestone.

Trimethoprim only protects against the most common bugs that cause utis. Perhaps he has a differfent one?

Thankyou; I may be splitting hairs. I guess I worry he's put on weight without me realising (as recently) and should be a bit higher. But from that PoV I feel he should be on a bit more than the tiny increments (as they did via hospital when he was tiny) to 'cover him' so to speak.

He's also tall and skinny; another child of the same height would weigh more iykwim.

Doesn't seem to have been a uti as the Dr hasn't replied, but he also seems but better.

So then I question if he's had a mild one that may have been fought off?!

I think my biggest issue is that we never realised he had any symptoms as was dx at 14 weeks - I'd gone to question normal reflux. He was bejnv bit more sick than usual but carried on being a very awkward sicky baby well after the uti! When first on the amoxycillin for it he became very sleepy, but no other noticeable symptoms eg smell.

And the paediatrician was very insistent we test wee every time he was poorly... (But they're a bit wee testing crazy at this hospital)