Azithromycin
"I had a 3-day course of Azithromycin (Z-Pack) to stop a case of Bronchitis, and it worked. Unfortunately, the bacteria (I think) got into my inner ear. Now I am starting a 5-day course (at my request) for the earache. If these drugs don't work it's often not the fault of the drug itself, but of the misuse by previous patients and/or doctors, leading to drug-resistant bacterium.  Note: I resist taking drugs until my immune system seems not to be working."