..What kinds are there, and how do they work?..Antibacterials..Penicillins and cephalosporins
..Erythromycin and its relatives
..Sulfa drugs
..Trimethoprim and sulfamethoxazole
..Other bacteria killers..Nitrofurantoin
..Aminoglycosides
..Polymyxin B..Antivirals..What can we do about viruses -- if anything?
..Acyclovir
..AZT and Other Reverse-Transcriptase Inhibitors
..Protease Inhibitors
..Why you shouldn't use antibiotics for a cold
What are antibiotics?Antibiotics are medicines that help your body fight bacteria and viruses, either by directly killing the offending bugs or by weakening them so that your own immune system can fight and kill them more easily. The vast majority of antibiotics are bacteria fighters; although there are millions of viruses, we only have antibiotics for half-a-dozen or so of them. Bacteria, on the other hand, are more complex (while viruses must "live" in a "host" (us), bacteria can live independently) and so are easier to kill.(A note for the purists out there: strictly speaking, an "antibiotic" is a bacteria-fighting medicine that is derived from a biological source (plant, mold, or other bacteria). Since most people use the term "antibiotic" for any anti-infection medicine, I am doing the same here.)Kinds of AntibioticsThere are now so many different antibiotics on the market that it's hard for us to keep track of them all. Personally, I almost always look up the dose of an antibiotic when I prescribe it, just to make sure that I'm giving the right medicine in the right dose. I also tend to stick to a few antibiotics in my practice, so that I can stay familiar with their effects and side-effects; most pediatricians I know do the same.Penicillins and CephalosporinsIn the first part of this century, Alexander Fleming discovered that a mold calledPenicillium (the cells are pencil-shaped when you look at them under a microscope) produces chemicals which kills most of the bacteria nearby. (The