I am a 24 year old female. I got diagnosed with walking pneumonia...

I am a 24 year old female. I got diagnosed with walking pneumonia after having a chest X ray at my doctors office. The doctor prescribed z-pak. I went home and took the first 2 pills and about 2-3 hours after taking it I suddenly experienced uncontrolled rapid heart rate. My heart was pounding so hard i almost fainted. I work in the medical field, and knew immediately that I was in trouble. My husband drove me to the ER, where I was admitted with a heart rate of 186 beats per minute, I honestly felt like i was going to faint, or die. Once they ran several tests and ruled out anything major IE blood clot, they determined I was having an extreme allergic reaction to the z-pak. They gave me IV benadryl and steroids, which immediately started to bring my heart rate down. I do not take any medications ever, other than supplements, this is the first time in 9 years that I have had to take an antibiotic, and this was the only prescription I was taking that day.