Sulfa drugs (like TMP/SMX) inhibit the production of which vital precursor of nucleotide synthesis?
Folic Acid
TMP/SMX (Trimethoprim/Sulfamethoxazole)
- Inhibit folic acid synthesis.
- Good gram +ve and -ve coverage.
- Does not cover anaerobes reliably.
- Generally considered to be cidal.
- Used to treat UTI, bacterial diarrhea, and some pneumonias.
Which drugs interfere which the bacterial membrane?
Polymyxin and Daptomycin
Polymyxin
- Bind and alters CM permeability.
- Cidal
- Type B is a topical mixture.
- Type E is administered through IV or inhaled.
- Effective against gram -ve, especially highly resistant -ve bacilli.
Daptomycin
- Bind the CM and disrupts it.
- Cidal
- Effective against gram +ve cocci.
- Used against highly resistant +ve strains (MRSA & VRE).
Which drugs affect the bacterial cell wall? {Beta Lactams}
Patient Centred Care May Vary
- Penicillins
- Cephalosporins
- Carbapenems
- Monobactams
- Vancomycin
- Bacitracin
Which cell wall antimicrobials are cidal?
All of the main classes are cidal.
Penicillins
Penicillin, Amoxicillin, Ampicillin, Piperacillin
- All are cidal to bacteria which are dividing.
- All have some gram +ve and -ve coverage.
- Gram -ve coverage increases up the triangle.
- Piperacillin will also cover pseudomonas.
- The penicillins alone will not cover staphylococcus.
What two combinations of penicillins and beta lactamase inhibitors can be used to cover staphylococcus?
Amoxicillin + Clavulanate
Pipercillin + Tazobactam
Cloxacillin may also be used for staph/strep infections. However, it does not build on the coverage of the penicillin pyramid.
Cephalosporins
- Cidal drugs which affect cell wall synthesis.
- Good coverage of gram +ve with increasing gram -ve coverage as the generations increase.
- Third and fourth generations are able to cross the blood brain barrier (BBB).
- Third generation cephalosporins lose their staph coverage.
- HENPEK
What does HENPEK stand for?
H: Haemophilus influenza E: Enterobacter N: Neiserria P: Proteus E: Escherichia Coli K: Klebsiella
What are two first generation cephalosporins? What are they used to treat?
Cefazolin (IV) and Cephalexin (po).
They are often used to treat skin and soft tissue infections. They may be used for uncomplicated RTI.
What are NOT covered by the cephalosporins?
Listeria, enterococcus, and coagulase negative staphylococci.
What are two second generation cephalosporins? What additional coverage do they offer?
Cefuroxime (IV), Cefprozil (po).
They cover more gram -ve including HEN.
(Haemophilus influenzae, Enterobacter, and Neiserria)
What are four third generation cephalosporins? What is something NOT covered by third generation?
Cefotaxime, Ceftriaxone, Ceftazidime*(IV), and Cefixime (po).
*Covers pseudomonas but has decreased gram -ve coverage.
Third generation cephalosporins can cross the BBB but will not cover staph and has decreased gram +ve coverage compared to first generation.
What are two fourth generation cephalosporins?
What is their coverage like?
Cefepime and Ceftobiprole (IV).
Similar gram +ve coverage to first generation and the gram -ve coverage of the third generation with pseudomonas coverage.
Name a monobactam. Give some interesting facts about it.
Aztreonam.
- Bactericidal
- Only covers gram -ve.
- No anaerobe coverage.
- Beta lactamase resistant.
What are the carbapenems? How is their dissemination throughout the body?
Imipenem and Meropenem (the gorillacilins).
- Cover almost all bacteria which are pathogenic to humans.
- Meropenem has less side effects than imipenem.
- Bactericidal
- Penetrate body tissues and fluid very well.
Vancomycin
- Not a beta lactam but grouped with them.
- Bactericidal
- Vancomycin is a glycopeptide.
- Very narrow spectrum covering only some gram +ve bacteria.
- Effective against streptococci, enterococci, and staphylococci aureus.
Bacitracin
- Only used as a topical agent.
- Good gram +ve coverage.
Which drugs affect protein synthesis?
Clyde The Clinician Ate The Lousy Eggs
- Chloramphenicol
- Tigecycline
- Clindamycin
- Aminoglycosides (Gentamicin & Tobramycin)
- Tetracycline / Doxycycline
- Linezolid
- Erythromycins {Macrolides} (Erythromycin, Azithromycin, and Clarithromycin)
Which drugs, which affect protein synthesis, are bactericidal?
The aminoglycosides Gentamicin and Tobramycin.
What three drugs are macrolides? What do macrolides cover? What are they especially useful for?
Erythromycin, Azithromycin, and Clarithromycin.
Macrolides cover chlamydia, mycoplasma, gram +ve, and gram -ve respiratory bacilli.
They are especially useful against RTI and predominantly cover gram -ve bacilli like pneumonia.
Which protein synthesis drugs affect the 30S ribosome?
The aminoglycosides (Gentamicin and Tobramycin), tetracycline / doxycycline, and tigecycline.
