Antibiotics: The Classy Medication!

Posted on 10.07.2015

I chose the title for this blog article for two reasons. First of all, antibiotics are amazing medicines and secondly, when it comes to the final exam, students quite frequently miss questions that deal with the different classes of antibiotics.

The American Academy of Pediatrics recently updated an article entitled The History of Antibiotics published on If you have some time, it’s an interesting read. I would like to pull out just a couple of paragraphs from it to show why I think antibiotics are classy.

The term antibiotics literally means “against life”; in this case, against microbes, and the discovery of antimicrobial drugs (antibiotics) was one of the most significant medical achievements of the 20th century.

• Before antibiotics, 90% of children with bacterial meningitis died. Among those children who lived, most had severe and lasting disabilities, from deafness to mental retardation.
• Strep throat was at times a fatal disease, and ear infections sometimes spread from the ear to the brain, causing severe problems.
• Other serious infections, from tuberculosis to pneumonia to whooping cough, were caused by aggressive bacteria that reproduced with extraordinary speed and led to serious illness and sometimes death.

Through his discovery of penicillin in the 1920s, British scientist Alexander Fleming won the Nobel Prize in Physiology and Medicine. By 1941, other researches in Europe and the United States found that even low levels of penicillin cured very serious infections and saved many lives, and by the mid to late 1940s, it became widely accessible to the general public and newspapers hailed it as a “miracle drug!”

The first class of antibiotics we’ll discuss are the penicillins. A few of the most common of these are:  amoxicillin, ampicillin, dicloxacillin, nafcillin, and piperacillin. Notice that penicillins end in “cillin.” (a great study tip!) Some well-known brand names are Amoxil and Augmentin.

Another class of antibiotics are the, cephalosporins. These are broad-spectrum antibiotics because they are used on strains of bacteria that have become resistant to penicillin. You will recognize some of these brand names: Keflex, Rocephin, Ceftin. Looking at some of the generic names, you’ll again see a pattern you can remember for testing: cefuroxime, cefprozil, ceftriaxone, and cephalexin.  They all begin with the “cef” sound which sounds a lot like cephalosporin, right?

So what’s the alternative if a patient is allergic to penicillin? Macrolide antibiotics. These types of antibiotics reduce production of proteins, which bacteria need to survive, and this slows the growth of or even kills the bacteria. The most common macrolides are Zithromax (azithromycin), Biaxin (clarithromycin), and Ery-Tab (erythromycin). Notice that they all end in “mycin.”

One last class that we’ll talk about is quinolones. These work on bacteria by making it difficult or impossible to repair their DNA, and you’re probably familiar with these: Cipro (ciprofloxacin) and Levaquin (levofloxacin). Study tip: they both end in “floxacin.”

We will conclude this with a few important notes about antibiotics in general that you will need to know.

• Metronidazole (Flagyl) – Do not drink alcohol while taking this medication (not fun side effects)!
• Vancomycin – Fairly toxic and is considered a “drug of last resort.”
• Female patients will need to be informed that contraceptives can be less effective while taking an antibiotic and backup contraception should be used while taking the antibiotic.
• Penicillins or sulfa-containing medications should be counted on dedicated counting trays because of the high prevalence of penicillin and sulfa allergy in the general population.