Antimicrobials — basically just a list to learn :/ Flashcards
How to beta- lactam antibiotics work?
They disrupt the formation of the peptidoglycan cell wall
they do this by binding to penicillin binding site on bacteria
this inhibits the transpeptidation enzyme so it cant link the peptidoglycan chains
disruption to cell wall structure
What are the 3 main types of beta- lactam antibiotics?
- Penicillins
- Cephalosporins
- Carbapenems
What are penicillins?
give some examples
what are they used to treat?
- They are beta lactam antibiotics named after the fungi it was derived from
- Phenoxymethylpenicillin (Penicillin V)
◦ Flucloxacillin (Beta-lactamase resistant)
◦ Amoxicillin (Broad spectrum)
◦ Co-amoxiclav (Amoxicillin given in combination with the β-lactamase inhibitor clavulanic acid)
◦ Piperacillin (Extended spectrum; clinically encountered as one part of Tazocin) - Bacterial meningitis
◦ Bone and joint infections
◦ Skin and soft tissue infections
◦ Otits media
◦ Pneumonia
◦ UTIs
◦ STIs
What are Cephalosporins?
examples
what do they treat ?
Antibiotics (beta lactam) named for the fungus Cephalosporium acreminium from which they were derived
Ceftriaxone
Cefuroxime
Cefotaxime
wide range : Septicaemia ◦ Pneumonia ◦ Meningitis ◦ Biliary tract infections ◦ UTIs (especially in pregnancy or in patients unresponsive to other
drugs) ◦ Sinusitis
What are Carbapenems?
examples
What are they used for?
are they safe for penicillin allergy?
Beta lactam antibiotics
carba = carbon , penem = penicillin
- Meropenem
- Imipenem
- Ertapenem
Very broard spectrum
safe for penicillin allergy
What are Glycopeptide antibiotics?
how do they work?
examples
what type of bacteria do they treat?
what is their usual formulation and where is there an exception to this?
A class of antibiotics that disrupt the cell wall
Inhibit cell wall synthesis, but at a different stage in the pathway to Beta-lactams - blocks incorporation of the NAG-NAM-PEP repeat unit into the growing peptidoglycan chain
Vancomycin Teicoplanin (longer lasting)
Gram positive
usually IV form but in C. Difficule it is used orally as it treats a GI problem and isn’t absobrbed so stays in GI
What are the 5 antibacterial groups that disrupt protein synthesis ?
• Tetracyclines
◦ Aminoglycosides
◦ Macrolides
◦ Oxazolidinones
◦ Lincosamides
What are Tetracyclines?
how are they uptaken into antibiotics?
how do they work?
examples
what do they treat?
Who should they not be given to?
do they work by being bacteriostatic or bacterisidal
Antibiotics that disrupt protein synthesis and uptaken by active transport into organisms
they bind to the bacterial ribosomes therefore preventing tRNA from binding and preventing protein synthesis
Doxycycline
Tetracycline
◦ Respiratory tract infections (particularly atypical organisms)
◦ Acne
◦ Chlamydia
◦ Lyme disease
Pregnant and breastfeeding women and children as it stains developing teeth yellow
bacteriostatic
What are Lincosamides (Clindamycin)?
what do they act like?
what bacteria types is it active against?
Antibiotics that disrupt protein synthesis
act like macrolides
gram positive cocci e.g. penicillin restraint streptococci and anaerobic bacteria
What are Aminoglycosides?
how do they work?
Example
bactericidal or bacteriostatic?
What type of bacterial do they treat?
what are some important effects to monitor?
They antibiotics that inhibit bacterial protein synthesis at many points
Bind to bacterial rib some subunits - this leads to misreading of mRNA and misencorporation of amino acids and a non functioning protein
Gentacicimin
bactericidal
Gram negative e.g. Gram negative Septicaemia
renal and ear side effects - nephro/ototoxic
What are Macrolides?
How do they work?
examples
what is it similar to?
what is it usually used for?
Antibiotics that disrupt protein synthesis
they effect ribosomal translocation
◦ Clarithromycin
◦ Erythromycin
◦ Azithromycin
penecillin
atypical respiratory pathogens
What are Oxazolidinones (Linezolid)?
when are they used?
What type of bacteria do they treat?
what conditions do they treat?
Very broard antibiotics and used when other antibiotics have failed
treat gram positive and anaerobes
pneumonia, septicaemia , skin and soft tissue infection
What are Quinolones?
how do they act?
example
what type of bacteria is it good at targeting?
what conditions does it treat?
side effects?
Inhibit topoisomerase II (a bacterial DNA gyrase), the enzyme that produces a negative supercoil in DNA and thus permits transcription or replication
Common examples:
◦ Ciprofloxacin
◦ Levofloxacin
gram negative and gram positive
Complex UTIs, gonorrhoea,
◦ Tendinitis +/- rupture
◦ Aortic dissection - dilation
◦ Central nervous system effects (- inc. Convulsions)
What are the 2 antibiotics that interfere with folate synthesis/action
Two examples: ◦ Sulfonamides ◦ Trimethoprim
What are Sulfonamides?
how do they work?
bacteriostatic or bactericidal?
Examples
Antibiotics that disrupt folate synthesis
Metabolized into the active product Sulfanilamide
Sulfanilamide is a structural analogue of p- aminobenzoic acid (PABA), which is an essential precursor in the synthesis of folic acid, required for the synthesis of DNA and RNA in bacteria Sulfanilamide competes with PABA for the enzyme dihydropteroate synthetase, resulting in decreased production of folic acid
Bacteriostatic
◦ Sulfamethoxazole
◦ Sulfasalazine (poorly absorbed via GI tract, hence used in treatment of IBD)
