Sulfamethoxazole / trimethoprim
"As far as I am concerned,  this is a miracle drug.  I had a boil that wouldn't go away.  I tried soaking, tea tree oil and a lot of other homeopathic remedies.  The boil persisted for 3 months.  75$ for an urgent care visit, $4.00 for a 10 day prescription for it...4 days later, it's gone!  Yes, a little nausea at first...ALWAYS take it on a full stomach."