AntiInfectives Flashcards
What was the first mass produced AB?
Penicillin
How does Penicillin work (mechanism of action)?
Kills bacteria by destroying the cell wall
-portion of the chemical structure of Penicillin and some other ABs that is responsible for their antibacterial activity
Beta Lactam Ring
What are the other classes of AB that contain a Beta Lactam Ring?
Cephalosporins, Monobactams, Carbapenems
When a bacteria mutates and becomes resistant to Penicillin, what happens?
- when they mutate they lack the building protein that is susceptible to ABs
- they secrete an enzyme called penicillinase that splits penicillin’s beta lactam ring
What is the enzyme that is secreted by bacteria resistant to Penicillin?
Penicillinase
What is the general term for any enzyme that is secreted to resist the beta lactam ring?
Beta-lactamase
Why is Penicillin less effective against bacteria cells that are already formed?
-because penicillin works on destroying the cell wall, it is easier for it to be effective when the cell wall is under construction
How can genes that encode for penicillinase be transferred from one bacteria to another?
Conjugation
What happens when bacteria share the genes for penicillinase?
-this spreads the development of resistance
What type of bacteria is Penicillin useful against?
Mainly Gram+ (and mainly limited to Streptococcus now, due to resistance)
What do natural penicillins lack activity against?
Gram- bacteria
What type of penicillin has been developed that offers activity against Gram+ and some Gram- bacilli?
Aminopenicillins (broad spectrum penicillins)
What are some examples of Aminopenicillins?
Amoxicillin, Ampicillin
- broad spectrum plus have activity against Pseudomonas aeruginosa
- class includes Piperaciliin, Ticarcillin-clavulanate
Extended Spectrum Penicillins (antipseudomonals)
- type of penicillin developed that is resistant to penicillinase
- narrow spectrum of activity
- mainly used for Staph
Penicillinase Resistant Penicillin (antistaphylococcal)
How much of the dry weight of a bacteria cell consists of protein?
50%
Why is it that AB that kill bacterial protein synthesis do not also kill human ribosomes?
While bacteria protein synthesis works the same as in humans (DNA used as template to make mRNA, mRNA sent to ribosomes to make protein chain), human ribosomes are larger and denser than bacterial ribosomes
-class of Anti-infective
-alternative for patients who are allergic to penicillin
-most effective against Gram+
newer version (with enteric coating) causes less GI upset than original
-resistance developing
Macrolides
What is the #1 AB offender for C. diff infections?
Clidamycin
What are the three ways that drugs can block DNA synthesis?
1) inhibit synthesis of precursor bases or nucleotides
2) interact with or bind to DNA, preventing uncoiling or relaxation
3) bind to enzymes of replication, stopping the formation of new DNA strands
Which AB turns urine an orangey-red colour or stains contact lenses?
Rifampin
- class of Anti-infective
- active against a broad spectrum of microorganisms
- traditional choice for UTIs
- widespread use has lead to increase of resistant strains
- classified by their absorption and excretion qualities
- suppresses bacterial growth by inhibiting synthesis of folic acid (only in bacteria)
- lots of allergies
- example: trimethoprim-sulfamethazole
Sulfonamides (aka Sulfa Drugs)
- class of Anti-infective
- first mass produced AB
- kills bacteria by destroying cell wall
- antibacterial activity due to beta lactam ring
- lyses growing bacterial cells that are building cell walls
Penicillin
- class of Anti-infective
- over 20 types
- 5 generations
- generally considered safe
- some cross reactivity with penicillin allergic people
Cephalosporins
- class of Anti-infective
- broad spectrum of activity
- kill bacteria by inhibiting cell wall synthesis
- better against Gram- and multidrug resistant infections than most penicillins or cephalosporins
- low incidence of adverse effects
- examples: imipenem-cilastatin, doripenem, ertapenem, meropenem
Carbapenems
- class of Anti-infective
- five AB in this class
- each one has broad spectrum of activity against Gram+ and Gram-
- method of action= inhibit protein synthesis
- widespread resistance has developed
- food can reduce drug absorption by 50%
- patient should be monitored for pseudomembranous colitis cause by C. diff
example: tetracycline
Tetracyclines
- class of Anti-infective
- alternative AB for patients allergic to penicillin
- most effective against Gram+
- resistant strains are becoming more common
- enteric coating on newer drugs helps with GI irritation
- examples: erythromycin
Macrolides
- class of Anti-infective
- bind to 30S ribosomal subunits
- considered narrow spectrum drugs
- reserved for serious systemic infections
- effective against aerobic Gram- (like Pseudomonas, Enterobacteriaceae family, E. coli, Serratia, Proteus, Klebsiella
- must be given parenterally
- examples: gentamycin
Aminoglycosides
- class of Anti-infective
- act on two enzymes in the DNA replication process
- bind to DNA gyrase, inhibiting its ability to relax the DNA supercoil
- bind to topoisomerase IV so the two daughter cells cannot migrate to opposite sides, and division cannot be completed
- example: Ciproflaxin
Fluoroquinolones
- class of Anti-infective
- anti-infective drugs used only for UTIs
- given by oral route
- not for systemic infections
- do not reach high concentrations in the blood
- used when infections are resistant to TMP-SMZ or fluoroquinolones
- example: nitrofurantoin
Urinary Tract Antiseptics
What different mechanisms of action are used by Anti-Fungal drugs?
- inhibition of Nucleic Acid Synthesis
- inhibition of Glucan Synthesis
- inhibition of Ergosterol Synthesis
- disruption of Membrane Integrity
- disruption of Microtubul Formation
- class of Anti-Infective
- largest and most versatile group of antifungals
- broad spectrum
- can be administered PO
- have superior safety profile
- two chemical classes
- example: fluconazole
Azoles
Which ABs are cell wall inhibitors?
Penicillin
Cephazolin
Vancomycin
Which ABs are protein synthesis inhibitors?
Tetracycline
Erythromycin
Gentamycin
Which ABs are bacterial DNA replication inhibitors?
Ciprofloxacin
Which ABs are folic acid inhibitors?
Trimethoprim-sulfamethoxazole (TMP-SMZ)
Which ABs are urinary tract antiseptics?
Nitrofurantoin
Which ABs are antifungals?
Amphotericin B
Flucanozole
Nystatin
Which antifungals are systemic antifungals?
Amphotericin B
Flucanozole
Which antifungals are superficial antifungals?
Flucanozole
Nystatin
Which anti-infectives can cause Steven’s Johnsons syndroms?
Trimethoprim-sulfamethoxazole (TMP-SMZ)
Flucanozole (in immunosuppressed patients)
Which anti-infective can cause tendonitis and tendon rupture?
Ciprofloxacin
Which serious side effects does Amphotericin B have?
- cardiac arrest
- ototoxicity
- nephrotoxicity
Which anti-infective can cause red man syndrome?
Vancomycin
Which serious side effects do Gentamycin and Vancomycin have?
- ototoxicity
- nephrotoxocity
Which anti-infective can cause discoloration of teeth?
Tetracycline
Which anti-infective can cause cardiotixicity with risk for torsades de pointes?
Erythromycin
Which anti-infectives effect Gram+ bacteria?
Penicillin
Vancomycin
Which anti-infectives effect Gram- bacteria?
Ciprofloxacin
Which anti-infectives effect Gram+ and Gram- bacteria?
Cephazolin Tetracycline Erythromycin Gentamycin Trimethoprim-sulfamethoxazole (TMP-SMZ) Nitrofurantoin
Which anti-infectives have a risk of ototoxicity?
Vancomycin
Erythromycin
Gentamycin
Which anti-infectives have a risk of hepatotoxicity?
Vancomycin
possibly Erythromycin
Which anti-infectives have a risk of nephrotoxicity?
Gentamycin
Which anti-infectives have a pregnancy classification of C or D?
Vancomycin Tetracycline Gentamycin Cyprofloxacin Trimethoprim-sulfamethoxazole (TMP-SMZ) Flucanozole
Which anti-infectives have a pregnancy classification of B?
Nitrofurantoin (dangerous for neonates, not to be used close to term) Nystatin Penicillin Cephazolin Erythromycin
