Antimicrobials I and II - Antibacterial Drugs Flashcards
Structure of bacteria of pharmacological interest - cell wall
all bacteria have a cell wall that consists of peptidoglycan
Structure of bacteria of pharmacological interest - peptidoglycan
a macromolecule composed of peptides and sugars that provide a rigid support structure that is found only in bacteria
Thick = gram pos
Thin = gram neg
Structure of bacteria of pharmacological interest - Lipopolysaccharide
makes up the outer membrane structures of gram neg bacteria cell wall and consists of phospholipid and polysaccharides
Structure of bacteria of pharmacological interest - cytoplasmic membrane
similar in structure to the eukaryotic cell membrane
Structure of bacteria of pharmacological interest - cytoplasm
contains the ribosome, nutrients, metabolites, plasmids, nucleoid DNA
Size of bacteria
Bacteria are small
0.2-5 um
Shape of bacteria - cocci
round
diplo = pair
strepto = chain
staphylo = grape like cluster
Shape of bacteria - bacilli
rods
Shape of bacteria - spirochetes
spiral shaped
Shape of bacteria - pleomorphic
many shaped
Nomenclature
Named by staining and shape (gram positive cocci)
Named by genus and species (escherichia coli)
Pathogenicity
when bacteria have neg impact or harmful effect on human health they are said to be pathogenic
Bacteria have harmful effects because they
compete with the host for nutrients
can stimulate an immune response ultimately causing tissue destruction
release toxins
Principles of chemotherapy - chemotherapy =
treatment of a disease with the use of chemicals to kill or impair the growth of microorganisms or cancerous cells
Principles of chemotherapy - antibmicrobial chemotherapy
grounded in principles of germ theory disease
agents aimed at eradicating microorganisms
Principles of chemotherapy - antibmicrobial chemotherapy - graph
as you increase antimicrobial agent/therapy, there is a decrease in the organism burden because you are killing stuff
Principles of chemotherapy - selective toxicity
aimed at killing or impairing growth of the specific target organism without harming the host
Principles of chemotherapy - Drug targets
aim to achieve selective toxicity by using drugs targeted to structures unique to the microorganism (like cell wall)
Principles of chemotherapy - Drug targets - common strategies for killing or inhibiting microorganism growth will be to target
folate synthesis needed to make DNA
disrupting mRNA synthesis
blocking protein synthesis
disrupting cell wall or membrane synthesis
Principles of chemotherapy - Bactericidal
agent that will kill the bacteria
once the organism is exposed to the drug, it is no longer viable
Principles of chemotherapy - bacteriostatic
an agent that will inhibit growth of the bacteria but will not kill the bacteria
Principles of chemotherapy - narrow spectrum
a drug that has an effect on one type or species of organisms
Principles of chemotherapy - If a particular pathogen is known to be the causative agent for a given disease/infection, using ____ is a logical choice
narrow spectrum antibiotic
Principles of chemotherapy - broad spectrum
a drug that has an effect on a wide variety of organisms
Principles of chemotherapy - If the causative agent is not known, an approach may be to treat with ___
broad spectrum antibiotic
Principles of chemotherapy - prophylactic therapy
treatment in the absence of infection in order to prevent disease
Principles of chemotherapy - pre emptive therapy
treatment of high risk patients that have become infected but are asymptomatic
Principles of chemotherapy - empirical therapy
treatment of a symptomatic pt without further testing or confirmation of the organism
Principles of chemotherapy - definitive therapy
tx once the pathogenic organism has been identified and appropriate drug identified
Principles of chemotherapy - suppressive therapy
generally a low dose therapy used as a secondary prophylaxis
problem that caused initial infection is likely to still be present
Principles of chemotherapy - resistance
an organism is said to develop resistance to a chemotherapeutic agent when the agent is no longer or less effective toward an organism
Resistance develops as a result of organismal changes and/or clinical practice
Principles of chemotherapy - resistance develops due to
1 - reduced drug entry into organism
2 - inc drug export from organism
3 - expression of enzymes by organism that destroy the drug
4 - change in expression enzymes that activate the drug
5 - impaired drug binding to original target
6 - development of new or diff pathway that are not inhibited by drug
Principles of chemotherapy - Bacteria will develop resistance through the
acquisition of new genetic material or a mutation in the existing genome that is selected under clinical/antibiotic pressure
General tx strategies
target cell wall and membrane
target protein synthesis
target DNA/RNA synthesis and function
General tx strategies - target cell wall and membrane synthesis - how
1 disrupt cell wall structure and rigidity which alters function of wall, homeostasis, and induces autolysis
2 punches holes in membrane with detergents that alter permeability
General tx strategies - target protein synthesis - how
drugs that bind bacterial specific ribosome and inhibit protein synthesis or cause misreading during translation
result is change in bacterial metabolic function, impaired growth, and cell death
General tx strategies - target DNA/RNA synthesis and function - how
disrupt the structure, synthesis or function of DNA or RNA leading to impaired growth and reproduction
General tx strategies - target cell wall and membrane synthesis - Cell wall synthesis inhibitors are (1) _____ which includes what
Beta lactam compounds!
Includes penicillins, cephalosporins, monobactams, and carbapenems
General tx strategies - target cell wall and membrane synthesis - penicillins
Natural - penicillin G and V
Synthetic - Amoxicillin! and methicillin
Natural agents have limited spectrum while synthetic have broader
General tx strategies - target cell wall and membrane synthesis - penicillins - MOA
Bind to and inhibit group of enzymes called penicillin binding proteins (PBPs)
The PBPs play a role in cell wall synthesis
General tx strategies - target cell wall and membrane synthesis - penicillins - key adverse effects
HYPERSENSITIVITY! (5%) rash, hives, itching, resp diff, anaphylaxis
CNS - confusion, hallucination
Blood - anemia, thrmbocytopenia
General tx strategies - target cell wall and membrane synthesis - cephalosporins
Used frequently if penicillin not tolerated (mild rx to pen)
In general, these are more resistant to B lactamase so they are not as susceptible to degredation
They are organized into four groups/generations based on their spectrum of activity
General tx strategies - target cell wall and membrane synthesis - cephalosporins - generation
increase spectrum as you move 1-4 1 - Cephalexin (+) 2 - Cefoxitin (+ and -) 3 - Ceftriaxone (broad -, limited + use) 4 - Cefepime (broad + and broad -)
General tx strategies - target cell wall and membrane synthesis - cephalosporins - MOA
bind to and inhibit PBPs
General tx strategies - target cell wall and membrane synthesis - cephalosporins - Key adverse effects
HYPERSENSITIVITY - rash, hives, itching, resp diff, anaphylaxis
Metabolism - need to avoid alcohol
Blood - bleeding disorder (2-6%)
General tx strategies - target cell wall and membrane synthesis - Monobactams
Only one agent - Aztreonam
Spectrum of activity is limited to gram - rods
Important feature includes penetration of CSF
Tx serious infections like pneumonia, meningitis, sepsis
General tx strategies - target cell wall and membrane synthesis - Monobactams - MOA
bind and inhibit PBPs
General tx strategies - target cell wall and membrane synthesis - Monobactams - Key adverse effects
Hypersensitivity - decreased severity though!
Skin rashes, itching
General tx strategies - target cell wall and membrane synthesis - Carbapenems
Imipenem, ertapenem, meropenem
Spectrum of activity includes btoh gram + and -
Resistant to B lactamase but susceptible to similar enzyme (carbamenemase)
Imipenem is inactived in kidney so is administered with cilastatin to prevent inactivation
General tx strategies - target cell wall and membrane synthesis - Carbapenems - key pharmacological effect
related to ability of these agents to penetrate tissue and fluids very well
access to a lot of compartments in the body
General tx strategies - target cell wall and membrane synthesis - Carbapenems - MOA
bind to and inhibit PBPs
General tx strategies - target cell wall and membrane synthesis - Carbapenems - Adverse effects
Hypersensitivity - less severe! (less than 1%) - skin rash, itching
CV - hypotension
CNS - confusion, tremor, seizures
General tx strategies - target cell wall and membrane synthesis - Others - Glycopeptide antibiotics
Vancomycin! produced by two specific bacteria
commonly use in tx of bloodstream infections, endocarditis, and meningits
Resistance is developing
General tx strategies - target cell wall and membrane synthesis - Others - Glycopeptide antibiotics - MOA
Prevents elongation of the peptidoglycan cell wall structure
General tx strategies - target cell wall and membrane synthesis - Others - Glycopeptide antibiotics - adverse effects
Skin irritation at injection site
FLUSHING (red neck syndrome)
General tx strategies - target cell wall and membrane synthesis - Others - Polypeptides and detergents
Bacitracin (polypeptide) and polymyxin B (detergent)
often used together topically for skin infections
General tx strategies - target cell wall and membrane synthesis - Others - Polypeptides and detergents - Bacitracin
Polypeptide - spectrum of activity is broad and includes gram + and - bacteria
General tx strategies - target cell wall and membrane synthesis - Others - Polypeptides and detergents - polymyxin B -
detergent
spectrum of activity is primarily gram -
General tx strategies - target cell wall and membrane synthesis - Others - Polypeptides and detergents - MOA
Bacitracin - inhibits cell wall synthesis by blocking incorporation of amino acids and nucleic acids into cell wall
Polymyxin B - punches hole in membrane by binding to phospholipids in cell membrane
General tx strategies - target cell wall and membrane synthesis - Others - Polypeptides and detergents - key adverse effects
Bacitracin - hypersentivity - skin rash, itching, (rare)
Polymyxin B - rare adverse effects when administered topically
General tx strategies - target cell wall and membrane synthesis - Beta lactamase inhibitors are what
Clavulanic acid used in combination with amoxicillin (augmentin) for example
General tx strategies - target cell wall and membrane synthesis - beta lactamase inhibitors MOA
inhibit beta lactamase
General tx strategies - target cell wall and membrane synthesis - beta lactamase inhibitors key adverse effects
similar to the penicillin agent used in combination
so hypersensitivty
General tx strategies - protein synthesis inhibitors include what
Aminoglycosides
Macrolides
Tetracycline
Few other specific compounds
General tx strategies - protein synthesis inhibitors - in general, their MOA is what
disrupt process of translation by targeting molecular machinery (50S and 30S) that is needed to translate mRNA to protein
disrupts the ribosome subunits
General tx strategies - protein synthesis inhibitors - Aminoglycoside ex
Streptomycin
Gentamicin
Neomycin
BROAD SPECTRUM
General tx strategies - protein synthesis inhibitors - Aminoglycoside - unique features
Used in combination with beta lactam antibiotic to treat serious gram neg infection
OFTEN used in combination and not alone
General tx strategies - protein synthesis inhibitors - Aminoglycoside - MOA
Binds 30S disrupts initiation of peptide formation
General tx strategies - protein synthesis inhibitors - Aminoglycoside - Key adverse effects
kidney - renal tubular necrosis
EAR - OTOTOXICITY - dizzy, ringing, fullness
Skin - hypersensitivity
General tx strategies - protein synthesis inhibitors - Macrolides ex
Erythromycin
Clarithromycin
Azithromycin
Spectrum - mostly gram pos, some neg
General tx strategies - protein synthesis inhibitors - Macrolides - MOA
Binds to 50S and prevents elongation of peptide
General tx strategies - protein synthesis inhibitors - Macrolides - Key adverse effects
GI (2-18%) Change of GI upset is high on z pack!
skin - hypersensitivity
General tx strategies - protein synthesis inhibitors - Tetracyclines ex
Tetracycline
Doxycycline
General tx strategies - protein synthesis inhibitors - tetracycline MOA
Binds 30S
General tx strategies - protein synthesis inhibitors - tetracycline key adverse effects
GI
SKIN - PHOTOSENS, hypersens
NUTRITION INTERACTION - binds Ca which impairs growth of calcified tissue esp. during growth (bone, teeth) - need to be careful with pregnant pt or child
General tx strategies - protein synthesis inhibitors - Others - name and MOA
Chloramphenicol
Clindamycin
Both bind to 50S
General tx strategies - protein synthesis inhibitors - Others - Chloramphenicol - when used
Rare, except for serious infections like typhus and rocky mountain spotted fever
can also be used for eye infections
General tx strategies - protein synthesis inhibitors - Others - Chloramphenicol - Adverse effects
GI
SUPERINFECTION - oral and vaginal candidiasis (suppresses normal biota and inc risk of yeast infection)
General tx strategies - protein synthesis inhibitors - Others - Clindamycin - when used
2nd line agent as alternative to penicillin and erythromycin for tx of local and systemic infection
General tx strategies - protein synthesis inhibitors - Others - Clindamycin - key adverse effects
GI
skin - hypersentivity, shock
General tx strategies - DNA/RNA synthesis inhibitors - what are 4 ways
Antifolate drugs - inhibit synthesis of DNA
Gyrase and Topoisomerase inhibitors - inhibit winding and unwinding
DNA damage - damage integrity of DNA
Replication inhibitors
General tx strategies - DNA/RNA synthesis inhibitors - what are they
Rifamycins Sulfonamides Trimethoprim TMP-SMX Fluroquinolones Metronidazole
General tx strategies - DNA/RNA synthesis inhibitors - Rifamycins are what
Rifamin
Used in tx of disease caused by mycobacterium like TB and leprosy
General tx strategies - DNA/RNA synthesis inhibitors - Rifamycins MOA
Replication inhibitor by inhibiting conversion of DNA to RNA and inhibiting RNA synthesis
General tx strategies - DNA/RNA synthesis inhibitors - Rifamycins key adverse effects
GI
Hypersens (6%) - mild, rash/fever
Liver - changes in function
General tx strategies - DNA/RNA synthesis inhibitors - Rifamycins - common use
infection of prosthetic devices
General tx strategies - DNA/RNA synthesis inhibitors - Antifolate drugs - do what and what are ex
inhibit DNA synthesis
Sulfonamides
Trimethoprim
Trimethoprim-sulfamethoxazole (TPM-SMX)
General tx strategies - DNA/RNA synthesis inhibitors - Antifolate drugs - Sulfonamides - ex
Sulfadiazine
Sulfamethoxazole
Sulfamethizole
General tx strategies - DNA/RNA synthesis inhibitors - Antifolate drugs - Sulfonamides - MOA
Substitutes for precursor and then you get competitive inhibition
General tx strategies - DNA/RNA synthesis inhibitors - Antifolate drugs - Sulfonamides - key adverse effects
GI
Skin - hypersens, PHOTO!
Urinary - causes cystalluria, hematuria, obstruction
General tx strategies - DNA/RNA synthesis inhibitors - Antifolate drugs - Trimethoprim - ex
Trimethoprim!
Pyrimethamine
General tx strategies - DNA/RNA synthesis inhibitors - Antifolate drugs - Trimethoprim - commonly used to tx what
UTI
General tx strategies - DNA/RNA synthesis inhibitors - Antifolate drugs - Trimethoprim - MOA
inhibitor of bacterial dihydrofolate reductase - leads to impaired DNA synthesis
General tx strategies - DNA/RNA synthesis inhibitors - Antifolate drugs - Trimethoprim - Key adverse effects
GI is the most common!
Blood - hyperkalemia (geriatrics), anemia!!!
skin - hypersens, itching
CNS - HA, dec appetite
General tx strategies - DNA/RNA synthesis inhibitors - Antifolate drugs - Trimethoprim-sulfamethoxazole (TPM-SMX) is used for what
UTI and prostatitis
Also, low dose can be used to treat recurrent UTI
Combo can also tx pneumonia and salmonella
General tx strategies - DNA/RNA synthesis inhibitors - Antifolate drugs - Trimethoprim-sulfamethoxazole (TPM-SMX) - MOA
Synergistic combination!!! Target diff enzymes in same pathway so work synergistically to get a greater effect
General tx strategies - DNA/RNA synthesis inhibitors - Antifolate drugs - Trimethoprim-sulfamethoxazole (TPM-SMX) - key adverse effects
Individual side effects
Sulf - GI, skin (photo), UT
Trim - GI, Blood (hyperK and anemia), skin, CNS
General tx strategies - DNA/RNA synthesis inhibitors - Fluoroquinolones - ex
Ciprofloxacin
Levofloxacin
General tx strategies - DNA/RNA synthesis inhibitors - Fluoroquinolones - used in tx of
urinary, GI, and resp infections as well as some STDs like gonorrhea
General tx strategies - DNA/RNA synthesis inhibitors - Fluoroquinolones - MOA
Inhibits the winding and unwinding needed for replication
General tx strategies - DNA/RNA synthesis inhibitors - Fluoroquinolones - key adverse effects
A LOT GI - 15% - n/v, diarrhea! Skin - rash, itch, PHOTO Kidney - toxicity Bone/Joints - tendinopathy!
General tx strategies - DNA/RNA synthesis inhibitors - Metronidazole used why
in treatment of abdominal infections, vaginitis, clostridium difficile colitis, brain abscess
General tx strategies - DNA/RNA synthesis inhibitors - Metronidazole - MOA
Prodrug - inactive until taken up by organism - binds to DNA and disrupts function and causes damage
General tx strategies - DNA/RNA synthesis inhibitors - Metronidazole - key adverse effects
GI HIGH! (10-12%)
PNS - neuropathy!!!
Metabolism - need to avoid alcohol
Considerations for PT - Skin and soft tissue - Uncomplicated infections often caused by ____, Tx _____
Often caused by staph aureus and Strep pyogens (gram pos)
Tx = penicillins, 1st gen cephalosporins
Considerations for PT - Skin and soft tissue - Complicated infections often caused by ____, Tx _____
often caused by E coli and pseudomonas aeruginosa (include burns, DM, pressure ulcer, surgical infection)
Can also include MRSA
Tx = penicillin plus lactamase inhibitor, carbapenem
Tx if severe = debridement, add vancomycin
MRSA = vancomycin
Considerations for PT - Skin and soft tissue - Key issues for PT
Precaution with MRSA - glove and handwash!
Adverse effects - hypersensitivity, penecillins can cause anaphylaxis, also might see some CNS effects like confusion, hallucinations
Considerations for PT - Bone and joint - most common causative organism of acute osteomyelitis and tx
S aureus and staphylococci
tx - vancomycin, cephalosporins
Considerations for PT - Bone and joint - Infectiosn following ortho surgery or vertebral infections are often caused by and tx
E coli and P aeruginosa
Tx = debridement, penicillin, lactamase inhibitor, carbapenem, vancomycin
Considerations for PT - Bone and joint - septic arthritis can be caused by what? Tx?
S aureus, S pyogens, strep pneumoniae, neisseria gonorrhoeae
Tx = ceftriaxone, vancomycin
Considerations for PT - Bone and joint - prosthetic joint infection are commonly caused by what and what is tx
S aureus and staphylococci
tx = rifampin
Considerations for PT - Bone and joint - key issues for PT
Adverse effects - hypersensitivity
Penicillin can cause anaphylaxis
Considerations for PT - Hospital acquired/healthcare associated pneumonia - caused by what? what is tx?
Gram neg bacilli (E coli, MRSA)
Multi drug resistance can be common!
Tx = cephalospoing, fluoroquinolone, penicillins, vancomycin for MRSA
Considerations for PT - Hospital acquired/healthcare associated pneumonia - Key issues for the therapist
Precaution with MRSA - gloves and handwashing
Cephalosporins, penicillins, and vanc - hypersens
Pen - anaphylaxis
Fluoro - photosensitivity and tendinopathy
Considerations for PT - UTI - uncomplicated - cause and tx
cause = e coli
tx - bladder, lower UTI = TMP-SMX
tx - kidney = TMP-SMX, fluoroquinolone
Considerations for PT - UTI - complicated - cause and tx
S aureus or enterococci
tx - TMP-SMX, fluoroquinolone
Considerations for PT - UTI - Key issue for therapist
TMP-SMX causes GI issues, hypersens, photosens!
Sulfa drugs can cause obstruction and/or hematuria
Elderly may have hyperkalemia
Fluroro - photosens and tendinopathy
Considerations for PT - Antibiotic associated diarrhea - cause
clostrdium difficile
Considerations for PT - Antibiotic associated diarrhea - which antibiotics are associated with causing it
fluroro, clindamycin, broad spectru penicillins, broad spectrum cephalosporins
Considerations for PT - Antibiotic associated diarrhea - tx
metronidazole
vancomycin if severe
Considerations for PT - Antibiotic associated diarrhea key issues for the therapist
diligence in preventing C diff - hand wash
Precautions - glove and gown
Vanco - can cause irritation to skin and flushing
Metronidazole can cause peripheral neuropathy, GI, and interacts with alcohol