My experience with antibiotic and pneumonia is that treatment beats feeling like I'm dying. Breathing trumps everything else until it's under control.
Seriously, DS tested faintly positive for Strep back when he was 8, so Amox was prescribed. He didn't improve, so we were sent in for a chest x-ray, which showed a pneumonia in one area of one lung. So the Amox dose was doubled. He seemed to be improving, but started breaking out in spots. We did some reading:this happens sometimes with antibiotics, no big deal. Then the spots started running together into big patches. We took him back in. Doc looked at him, listened to his lungs, ordered him an immediate dose of Prednisone (a cortico-steriod, serious med), and sent us into PGH to Children's Hospital. Long story short, he had Micoplasm Pneumonia, which does not respond at all to Amox. He needed a very different antibiotic. In addition, he is allergic to Penicillins, which is the family of antibiotics that Amox is in. The only reason he had seemed to be getting better was that he's got a heck of an immune system. The pneumonia had diffused throughout his lungs instead of being localized. Once he was on Zithromax, he began to truly get better, and the spots disappeared without any further treatment.
A week later, I started having the same symptoms as he did, but the doc we saw that Saturday would not prescribe "based on history". The fool. I still chuckle that when my temperature spiked to 105 (though as rational as I was, I'm thinking the thermometer may not have been accurate) in the middle of the night Sunday, he was the doc on call. He called me in the same med that DS had been prescribed: Zithromax. Amazingly enough, I was starting to feel better after the next day.
Everyone's experience will differ though. I'm just leery of the habit of starting with Amox for everything. Once they know it's bacterial, how difficult can it be to see which one it is to make sure the med being prescribed will actually work?