Nuva Ring + Vandazole

Hi!
I have been on Nuva Ring for about 6 months now, with no problems or terrible side effects. I went for a gyno check up this morning and found out I have a mild bacterial infection, so my doctor gave me Vandazole and told me to use it once or twice a day. I asked her about the effects it might have on my nuva ring's efficacy, but she didn't really give me an answer.
My question is, will it decrease the efficacy? If so, is it a huge decrease? My boyfriend and I use always use condoms anyway, but I want to be sure in case the condom breaks. Also, because the gel goes right into the vagina, if it does decrease efficacy, will I have to rinse it off when my infection clears, to make sure the gel's not sticking around and decreasing the Nuva Ring's effects constantly?
Sorry about the barrage of questions, but I figure this would be good for future reference as well.
Thanks!