I used to take niacin for a different reason. If the flushes become troublesome (they can make some people feel like they have bad burns all over their body), try slow-release niacin.
Also, ask your regular doc to monitor your liver function, as niacin can affect that. I had to stop taking it because it started shutting my liver down.
Hope it works for you all!
Your physician is certain that was a direct result of the niacin, and not because your liver was overloaded with cleaning toxins from the die-off? People without Lyme have taken doses over 10,000 mg daily and not suffered any liver issues. I know the heavy and prolonged neurotoxin release from killing the bacteria will put a big strain on anyone's liver.
I don't have Lyme. I was taking Niacin for hyperlipidemia, under doctor supervision. When I started, it was a low dose which was slowly increased over time to watch the reaction. Every time I took it, I flushed terribly. The flushes aren't dangerous, merely very distressing for some people. And certainly not everyone would get liver toxicity, but it is a known potential side effect. When I stopped the niacin the liver function went back to normal, so in my case that seemed to be the problem.