Antibiotic

try google...its been my saving grace many times!

Why does it matter?

http://www.emedexpert.com/classes/antibiotics.shtml

Although there are several classification schemes for antibiotics, based on bacterial spectrum (broad versus narrow) or route of administration (injectable versus oral versus topical), or type of activity (bactericidal vs. bacteriostatic), the most useful is based on chemical structure. Antibiotics within a structural class will generally have similar patterns of effectiveness, toxicity, and allergic potential.

Most commonly used types of antibiotics are: Aminoglycosides, Penicillins, Fluoroquinolones, Cephalosporins, Macrolides, and Tetracyclines. While each class is composed of multiple drugs, each drug is unique in some way.

Penicillins

The penicillins are the oldest class of antibiotics. Penicillins have a common chemical structure which they share with the cephalopsorins. Penicillins are generally bactericidal, inhibiting formation of the cell wall. Penicillins are used to treat skin infections, dental infections, ear infections, respiratory tract infections, urinary tract infections, gonorrhea.

There are four types of penicillins:

• The natural penicillins are based on the original penicillin-G structure. Penicillin-G types are effective against gram-positive strains of streptococci, staphylococci, and some gram-negative bacteria such as meningococcus.
  
• Penicillinase-resistant penicillins, notably methicillin and oxacillin, are active even in the presence of the bacterial enzyme that inactivates most natural penicillins.
  
• Aminopenicillins such as ampicillin and amoxicillin have an extended spectrum of action compared with the natural penicillins. Extended spectrum penicillins are effective against a wider range of bacteria.
  

Penicillins side effects

Penicillins are among the least toxic drugs known. The most common side effect of penicillin is diarrhea. Nausea, vomiting, and upset stomach are also common. In rare cases penicillins can cause immediate and delayed allergic reactions - specifically, skin rashes, fever, and anaphylactic shock. Penicillins are classed as category B during pregnancy.

Cephalosporins

Cephalosporins have a mechanism of action identical to that of the penicillins. However, the basic chemical structure of the penicillins and cephalosporins differs in other respects, resulting in some difference in the spectrum of antibacterial activity. Like the penicillins, cephalosporins have a beta-lactam ring structure that interferes with synthesis of the bacterial cell wall and so are bactericidal. Cephalosporins are derived from cephalosporin C which is produced from Cephalosporium acremonium.

Cephalosporins are used to treat pneumonia, strep throat, staph infections, tonsillitis, bronchitis, otitis media, various types of skin infections, gonorrhea, urinary tract infections Cephalosporin antibiotics are also commonly used for surgical prophylaxis. Cephalexin can also be used to treat bone infections.

Cephalosporins are among the most diverse classes of antibiotics, they are grouped into "generations" by their antimicrobial properties. Each newer generation has a broader spectrum of activity than the one before.

• The first generation cephalosporins include: Their spectrums of activity are quite similar. They possess generally excellent coverage against most gram-positive pathogens and variable to poor coverage against most gram negative pathogens. The first generation cephalosporins include:
  
  • cephalothin
    
  • cefazolin
    
  • cephapirin
    
  • cephradine
    
  • cephalexin
    
  • cefadroxil
    

  [*]The second generation cephalosporins. In addition to the gram positive spectrum of the first generation cephalosporins, these agents have expanded gram negative spectrum. Cefoxitin and cefotetan also have good activity against Bacteroides fragilis. Enough variation exists between the second generation cephalosporins in regard to their spectrums of activity against most species of gram negative bacteria, that susceptibility testing is generally required to determine sensitivity. The second generation cephalosporins include:

  • cefaclor
    
  • cefamandole
    
  • cefonicid
    
  • ceforanide
    
  • cefuroxime
    

  [*]The third generation cephalosporins have much expanded gram negative activity. However, some members of this group have decreased activity against gram-positive organisms. They have the advantage of convenient dosing schedules, but they are expensive. The third generation cephalosporins include:

  • cefcapene
    
  • cefdaloxime
    
  • cefditoren
    
  • cefetamet
    
  • cefixime
    
  • cefmenoxime
    
  • cefodizime
    
  • cefoperazone
    
  • cefotaxime
    
  • cefpimizole
    
  • cefpodoxime
    
  • ceftibuten
    
  • ceftriaxone
    

  [*]The fourth generation cephalosporins are extended-spectrum agents with similar activity against gram-positive organisms as first-generation cephalosporins. They also have a greater resistance to beta-lactamases than the third generation cephalosporins. Many fourth generation cephalosporins can cross blood brain barrier and are effective in meningitis. The fourth generation cephalosporins include:

  • cefclidine
    
  • cefepime
    
  • cefluprenam
    
  • cefozopran
    
  • cefpirome
    
  • cefquinome
    

hello...i want to know...based on classification of antibiotic...for example cephalosporin which have their generations. So is it means that third generation is strongest than first generation?

Not necessarily. Third generation may be more effective against an organism that developed resistance to a first generation. First generation is more effective against gram positive organisms whereas third generations more effective against gram negative organisms. Fourth generation is effective against gram neg including pseudomonas Fifth generation is more effective against MRSA.

I don't have an exact answer for you. However, I just have to say I recently was reading an Emergency Medicine journal (meant for doctors...some of it is way beyond my scope of practice, but some of it is very interesting) and it had several advertisements for "new" antibiotics. Now I'm not sure if these antibiotics were totally new or they were just new formulations/new additives for old drugs, I'm not sure.

I noticed you've posted a couple of places about this and seem to be struggling with the concepts.

It may help to STOP thing about antibiotics in terms of "strong".

An antibiotic's action or lack of action is tied directly to the organism causing the infection.

It doesn't matter how "strong" an antibiotic is, what matters is that it is the correct antibiotic for the organism.

This is a good point. We're dealing with different organisms now, or more resistant types of older organisms. A way to approach the question would for the OP to do some research on the common types of bacterial infections seen nowadays, what antibiotics are used to treat them, versus in the past, and what antibiotics were used then, and why they are no longer as effective.

Which could very well be what the teacher intended with the assignment.

thank you for your replying...i'd been searching in the drug books but i still do not understand the differences between of them. May i know what drug book for pediatric that suitable for me to have since then i've been start worjking pediatric ward. And plus which book for pediatric congenital cardiac nursing that are good for me to buy and to have. Can you give me some recommendation about the book.?

One more thing.. how about the 2nd generation of cephalosporin?

Did you look at the links that were posted in the other thread that you started? There was a lot of good information posted tehre.. What do you want to know about the 2nd generation cephalosporins?

Do you have a drug book? Most standard drug guides include pediatric dosings so it becomes a matter of which format YOU prefer. Some people prefer sorted by drug class others prefer alphabetical by generic name.

As far as pediatrics, some people recommend the Harriet Lane Handbook from Johns Hopkins, but that is

so for you the harriet lane handbook is good for me who work at pedaitric ward for congenital heatd disease?

i'm planning to buy one. But i want recommendation from you all.tQ

Harriet Lane is awesome but it is geared toward US/CAN physicians & residents so for some nurses it is TOO much information. You can get an idea by looking online at some of the online retailers or the publisher's website to determine if the book is appropriate for your needs.