re: Strangest side effect you had from a prescribed drug?

Broke out in horrible hives from amoxicillin. In college went to infirmary for a sore throat. Doc looked at throat and diagnosed me with a red throat(whatever that is). Sent me away with amoxicillin. A few days later I am at work and a coworker tells me I am breaking out in hives. By the time I get to the infirmary I am covered. Doc sees me and just says uh oh. Sends me immediately for a mono test. Positive for mono. Apparently there is some sort of reaction between mono and amoxicillin