There's a question raised in iVillage about allergies to penicillin. The concern of the patient was that, if a person is allergic to penicillin, would that mean that his infections or illnesses will be left untreated since he cannot be prescribed penicillin and other beta-lactam antibiotics?

Absolutely not. Although beta-lactam antibiotics are wide-spectrum antibiotics, meaning they can be effective against a wide array of infections, there are other options in cases where it is not possible to administer beta-lactams. According to Dr. Harold Oster, MD:

Most infections that you would develop later in life could be treated with the fluoroquinolone class. This class includes ciprofloxacin (Cipro), levofloxacin (Levaquin) and the newer drugs moxifloxacin (Avelox) and gatifloxacin (Tequin). We could also use the tetracycline class and the macrolides erythromycin (E-mycin), clarithromycin (Biaxin) and azithromycin (Zithromax). There are also other choices from other classes that would be safe for you to take.

So don't worry, there are lots of options when the time comes. Do not self-prescribe though. These are powerful antibiotics designed for specific conditions. If you're sick, let your doctor decide which is the best for you.