Antibiotics affecting HRT and causing bleeding? Help!

[ChrisPPancake]

I remember from the days way back when that on the pill you needed additional protection when taking antibiotics.
I've been on HRT over 2 years (non-cyclical), last period 2020 but prior to that only 2 in 2019! I was switched from oral to oestrogel/utrogestan in September if it's relevant (4 pumps/100mg orally).
On Friday urine dip was positive for leucocytes so I was given nitrofurantoin (Macrobid). I've had it before with no issues. Yesterday afternoon I started bleeding and it's got heavier. Had to get up and change pad in the night which I've never had to do before even when periods were v heavy.

Clutching at straws maybe but is it the antibiotics that have done it?! GP have no appointments available.

No change to HRT regime and no missed doses. Did throw up on a couple of days last week but in the mornings and I take the utrogestan in the evening. And there's absolutely no way I can be/could have been pregnant.

Hopeful bump?

I'd make an appt with your GP and ask for a referral for a scan.

I could be wrong but I don't think there is any evidence that antiBs affect HRT.

It's more likely that as you are using a lot of gel, the amount of Utrogestan is too low. The BMS recently commented on this and suggested that 200mgs might be better for women on a high dose (and 4 pumps is high.)

Thanks @JinglingSpringbells , that's really helpful. I hadn't read that about the increased dose of utrogestan but I guess it makes sense.

Actually managed to get a phone appointment this afternoon. Spoke with GP who asked me to put the bleeding aside for now (I wish 😂) while the rest of me gets better. Got to call back next week and he'll start the process. He said it was unlikely to be related to the antibiotics as well.

I had scans/hysteroscopy in 2021 and all was ok. I only went up to 4 pumps/day in December so maybe it is that?

Thanks again 😊

My oestrogen was high in November (on 4 pumps) and I changed to patches. I may be absorbing it even better from patches as I'm now bleeding a lot and sick of it. I'm back on gel and gradually reducing the dose to get off it, which will be better for me. It's likely you have too much oestrogen for progesterone, the balance is delicate apparently