I Overdosed on Niacin Yesterday

My doctor put me on prescription Niaspan/niacinamide for high triglycerides about 10 years ago. Normally, you take it at night before bedtime, so the flushing isn't as disturbing. The flushing was pretty bad but I didn't know how bad until I took the dose I had missed the night before at 7am the next morning. Everything was fine until I sat down in the teachers' lounge to eat lunch 6 hours later. All of a sudden I flushed red from head to toe. My lips and eyes swelled and I thought I was going to bust out of my clothes, like the Hulk. Scared the principal out of her wits. Although I assured her that this was simply a medication issue, looking back I wonder if it wasn't really an allergic reaction. At any rate, I never took it again!