Antibiotics - cell wall synthesis inhibitors
For others, go to our page on antibiotics.
Penicillins
About
- Narrow to medium spectrum antibiotics
- Mostly work on gram positive, with some exceptions
- A type of beta-lactam
Types & Bacteria
- Amoxicillin - pneumonia. gastric ulcer caused by Helicobacter pylori
- Benzylpenicillin - meningitis, Haemophilus
- Ampicillin - H. influenzae, Streptococci
- Pipricillin - Pseudomonas
Resistance
Have a beta-lactam ring as part of the structure. Many bacteria - most notably MRSA have a beta-lactamase enzyme, which breaks this ring down. In this case, other drugs have to be used, most commonly glycopeptides, like vancomycin.
Problems
People can be allergic to penicillins! So be aware! Less than 1% of people have an allergy to it, but it is the most common cause of allergic reaction. They may also be allergic to cephalosporins...
Cephalosporins
A "from the people that brought you penicillins" type of antibiotic, it is bacteriacidal and also has a beta lactam ring.
About
- broad spectrum antibiotics
- Like penicillin, a type of beta-lactam
- Basically, work on everything but they're less susceptible to beta-lactamases (enzymes which break down beta-lactams).
Types & Bacteria
These are only the examples I've heard of. There are absolutely loads of different cephalosporins.
- 1st generation: cefalexin
- 2nd generations: cefaclor, cefuroxime
- 3rd generation: cefotaxime, ceftazidine, ceftriaxone
There 4th and 5th generation cephalosporins but for the moment nobody really cares about them as doctors try and avoid using them.
Resistance
Have a beta-lactam ring as part of the structure. Many bacteria - most notably MRSA have a beta-lactamase enzyme, which breaks this ring down. In this case, other drugs have to be used, most commonly glycopeptides, like vancomycin.
Problems
About 5-10% of people allergic to penicillin are also allergic to cephalosporins. So be aware!
Glycopeptides
About
Inhibit peptidoglycan synthesis (in turn, inhibiting cell wall synthesis). What you really need to know is they are the badass antibiotic and are generally used when beta-lactams (the two sets above) won't work i.e. with MRSA. Essentially, these are drugs of last resort.
Types & Bacteria
- Teicoplainin - MRSA
- Vancomycin - life-threatening Gram-positive bacteria
Resistance
Mostly, nothing is resistant to them but they are the absolute last-line treatment. Vancomycin resistance has been seen in some bacteria.
Problems
Pain at the site of injection. Rarely (0.1-1%) nephrotoxicity