Chemotherapy Of Antimicrobial Infections Flashcards
Antimicrobials MOA 2
Interference with physiological pathways inhibits growth and multiplication or kill microorganisms
Antimicrobials MOA 3
Biochemical processes commonly inhibited: cell wall sysnthesis, cell membrane function, sysnthesis of 30s and 50s ribosomal subunits; nucleic acid sysnthesis
Characteristics of an ideal anti-infection agent
- Selective toxicity (bactericidal> bacteriostatic)
- Capable of penetration in concentration that exceeds several folds the MIC/MBC of potential pathogen, high affinity for site of action
- Resistant to inactivation and must not readily stimulate microbial resistance
- Orally active
- Long elimination half-life
- Devoid of adverse drug-drug interaction
- Absence of major organ toxic effect
- Absence of developmental or behavioral toxic effects
Factors to consider in the choice of antibiotics
- Microbial factors
- Host-related factors
- Drug-related factors
Classification of antibacterial agents
- Based on spectrum of activity (narrow or broad)
- Based on antimicrobial action (bactericidal or bacteriostatic)
- Based on mechanism of action (inhibition of cell wall synthesis, cell membrane function, protein synthesis, nucleic acid synthesis)
Ex of drugs that inhibit cell membrane function
Polymixins, daptomycin, polyene antifungals
Ex of drugs that inhibit protein systhesis
Aminoglycosides
Ex of direct inhibitor of DNA synthesis
Fluoroquinolones
Rifampicin as nucleic acid synthesis inhibitor
Forms stable complex with beta sub-unit of DNA-dependent RNA polymerase thereby inhibiting RNA synthesis (blocks RNA transcription)
Nitro-imidazoles like metronidazole as nucleic acid synthesis inhibitor
The nitro group is chemically reduced intracellularly in anaerobic bacteria and sensitive protozoans, to a reactive reduction product which interacts with DNa to cause a loss of helical DNA structure and strand breakage resulting in cell death
Antibiotic PD
- concentration-dependent or dose-dependent killing
2. Time-dependent killing
Concentration-dependent killing
–most important determinant of efficacy
The higher the concentration, the greater the bactericidal effect
—cmax/MIC ratio: aminoglycosides
AUC/MIC ratio: fluoroquinolones
Tome-dependent killing
- –most important determinant of efficacy:
- –goal:
Bactericidal effect is dependent on the length of time the bacteria are exposed to serum concentrations of at least 4x the MIC
- –time>MIC
- –goal: attain serum concentration of at least 4x MIC ofnjnfecting organism at all times for at least 40-50% of the dosing interval
Antibiotic absorption
To be effective the antibiotic has to be absorbed and penetrate into the infected compartment/organ; oral for mild to moderate infection and Iv for serious infections
Drugs with decreased biovailability with food
Ampicillin Azithromycin Didanosine, efavirenz, indinavir Erythromycin base/ether Isoniazid Itraconazole Norfloxacin Oxacillin,cloxacillin, etc Phenoxymethylpenicillin (penicillin V) Rifampicin Sulfisoxqzole Tetracyclin/oxytetracyclin
Drugs with increased bioavailability with food
Cefuroxime axetil
Fusidic acid
Griseofulvin
Nitrofurantoin
Unchanged bioavailability. Taken with or without food)
Amoxicillin, co-amoxiclav Cefadroxil Cefixime Chloramphenicol Ciprofloxacin Clarithromycin Clindamycin Cotrimoxazole Dapsone Doxycycline/minicycline Fluconazole Flucytosine Ketoconazole Pyrazinamide Linezolid Metronidazole Telithromycin
Distribution of antibiotics
Effectiveness of antimicrobial therapy is determined by the relationship of the concentration of drug reaching the site of infection and the MIC of the infecting organism
Excellent with or without inflammation
Chloramphenicol Ethionamide Fluconazole Isoniazid Metronidazole Pyrazinamide Rifampicin Sulfonamides Trimethoprim
Drugs good with inflammation
3rd generatiob parenteral cephalosporins Cefepime Aztreonam Ciprofloxacin, moxifloxacin Linezolid Meropenem Penicillin Vancomycin
Minimal or not good with inflammation
Aminoglycosides Lincosamides Macrolides Streptogramins Tetracyclins
No passage even with inflammation
AmphotericinB
1st 2nd gem cephalosporins
Cefoperazone and ceftaroline
Polymixin E
Metabolism of antibiotics
Relatively few administered as prodrugs and have to undergo biotransformation to become active ( isoniazid, chloramphenicol succinate/palmitate)
Some active antibiotics undergo biotransformation to form still active metabolites
Inhibit metabolism of other (metronidazole)
some enhance (rifampicin)
Antibiotics excretion
Via the kidney, nonrenal
Hepatobiliary excretion
Cefoperazone/ceftriaxone Chloramphenicol Clindamycon/doxycyclin Azithromycin Linezolod Metronidazole Most azole but nit fluconazole Mocifloxacin Nafcillin Quinupristi rifampicin
Renal and biliary excretion
Ampicillin Cefixime Isoniazid Oxacillin and related drugs Pyrazinamide Telithromycin
Renal excretion
Aciclovir Aminoglycosides Amphotericin B Aztreonam Carbapanemes Cephalosporins Clarithromycin Fluoroquinolones Penicillintetracyclin Vancomycin
Rationale for antibiotic combination therapy
1 provide broad spectrum for empiric therapy
- Treat polymicrobial infection
- Prevent/ delay emergence of resistance
- Decrease dose-related toxicity
- Obtain enhanced inhibition/killing synergism
Mechanism of antimicrobial synergism
- Blockade of sequential steps in metabolic sequence
- Inhibition of enzymatic inactivation
- Enhancement of antimicrobial uptake
[synergism]
Blockade of sequential steps in metabolic sequence
Sulfamethoxazole + trimethoprim
[synergism]
Inhibition of enzymatic inactivation
- Betalactamase inhibitor and beta lactam antibiotic
- Clavulanate K and amoxicillin
- Sulbactam and ampicillin
- Tazobactam and piperacillin
[synergism]
Enhancement of antimicrobial uptake
- Penicillin and aminoglycosides
- Ampicillin and gentamycin
- Ceftazidime and amikacin
Mechanism of antimicrobial antagonism and example
- Inhibition of bactericidal activity by bacteriostatic antibiotic (betalactams and tetracycline)
- Induction of enzymatic inactivation (rifampicin and protease inhibitors)
Mechanism of acquired drug resistance
1. Decrease
Decreased drug uptake or increase efflux of the drug ( tetracycline, quinolones, aminoglycoside, macrolides, chloramphenicol)
Mechanism of acquired drug resistance
2. Enz
- Enzymatic inactivation of the drug ( penicillin, aminoglycosides, chloramphenicol)
Mechanism of acquired drug resistance
3. Dec conv
Decreased conversion of a drug to the active growth inhibitory compound (flucytosine)
Mechanism of acquired drug resistance
4. Inc
Increased concentration of the metabolite antagonizing the drug action (sulfonamides)
Mechanism of acquired drug resistance
5. Altered
Altered amount of drug receptor (trimethoprim)
Mechanism of acquired drug resistance
6. Dec aff
Decreased affinity of receptor for the drug ( lsulfonamides, streptomycin, rifampicin)
Prophylactic antibiotic therapy
To prevent infection in those exposed or to prevent development of potentially dangerous disease in those who already have evidence of infection
Surgical chemoprophylaxis
- Antibiotic should be active vs common surgical wound pathogens; unnecessarily broad coverage should be avoided
- Efficacy in clinical trials
- Achieve concentrations higher than the MiC of suspected pathogens and these concentrations must be present at the time of incision
- Shortest possible course
- Reserved for therapy of resistant infections
- The least expensive
General adverse effects
1. Hypersensitivity 2 idiosyncratic 3. Toxicity rxn 4. Biologic anf metabolic alterations in the host 5. Treatment failure/ relapse 6. Masking effect 7. Adverse drug interaction
Misuse or abuse practices
- Use in self-limited infections
- Empiric use in fever of undetermined origin
3! Misuse of chemoprophylaxis - Misuse of antibiotic combinations
Antimicrobials MOA 1
Ligands whose active chemical moiety binds with microbial protein receptors which are essential components of biochemical reactions in the microbes
Penicillin MOA
Binds with PBP causing selective inhibition of transpeptidase
Penicillin mechanism of resistance
Inactivation by beta lactamase
Penicillin drugs
Penicillin G (benzylpenicillin G) Penicillin V (phenoxymethylpenicillin)
Anti-staphylococcal penicillin
Methicillin
Naphcillin, oxacillin
Dicloxacillin, cloxacillin, flucloxacillin
Extended-spectrum penicillin
- Aminopenicillin (amoxicillin, ampicillin)
- Ureidopenicillin (piperacillin)
- Carboxylenicillin (ticarcillin, carbenicillin)
Penicillin PD
High protein binding
Highly distributed in body fluids and tissues
Poor intracellular concentrations
Urine excretion
PEnicillin PD
Time-dependent killing: efficacy is directly related to time above MIC and becomes independeny of concentration once the MiC has been reached
Penicllin G drug of choice for
Pemicillin V
1. Strep pyogenes Strep pneumoniae Non beta lactamase producing staph aureus Enterococcus faecalis Neisseria meningitidis Treponema pallidum Leptospira spp Clostridium tryani actinomyces 2. Strep pyogenes
Uses for anti staphylococcal penicillins
Methicillin-sensitive S. Aureus
Uses for aminopenicillin
Strep pneumoniae Shigella Salmonella E. Coli Listeria monocytogenes Enterococcus faecalis
Use for carboxypenicillins
Pseudomonas aeruginosa
Ureidopenicillin use
P. Aeruginosa
Penicillin AE common
Hypersensitivity, rash, GI disturbances
Penicillin AE occasional
Hematologic disturbances
Pseudomembranous colitis
Penicillin AE rare
Anaphylactic shock Serum sickness Muscle irritability, seizure Hemolytic anemia Interstitial nephrittis Hepatitis Agranulocytosis, neutropenia
Beta lactamase inhibitor moa
Bind irreversibly to the catalytic site of beta lactamases rendering them inactive
First gen cephalosporins
Oral
Uses
- Cephalexin
Cefadroxil - Strep and staph; surgical prophylaxis; e. Coli
Second gen cephalosporin
Oral
Uses
1. Cefuroxime Cefaclor Cefprozil Loracarbef 2. Bacteroides fragilis; broader than first gen
3rd gen cephalosporin
Oral
Uses
- Cefixime
Cefpodoxime
Cefdinir - Meningitis caused by penicillin-resistant strep pneumoniae; pseudomonas aeruginosa; neisseria gonorrhea; MDR salmonella typhi, etc
Cephalosporins AE common
GI disturbances, thrombophlebitis
Cephalosporins AE occasional
Hypersensitivity, serum sickness-like reactions, bile sludging, pseudocholelithiasis, hematologic disturbances, disulfram like rxns
Cephalosporins AE rare
Anaphylactic shock, interstitial nephritis and tubular necrosis, pseudomembranous colitis, hepatitis, seizure
Monobactam occasional AE
Hypersensitivity
GI disturbances
Transaminitis
Local reactiob
Monobactam rare AE
Hematologic disturbances
Pseudomembranous colitis
Carbapanem uses
ESBLs, serious miced aerobic and anaerobic infections
Enterobacter spo
Carbapanem AE common
GI disturbances
Carbapanem AE occasional
Hypersensitivity,
Hematologic disturbances,
Local reactions
Carbapanem AE rare
Seizure, hallucination, anaphylactic shock, serum sickness, pseudomembranous colitis
Glycopeotides MIA
- Inhibit cell wall synthesis
2. Inhibit transglycosylase
Glycopeptide PK
Tine-dependent killing: efficacy is directly related ti time above MIC, and becomes independent of concentration once the MIC has been reached
Vancomycin uses
Caused by MRSA; for coagulase negative staphylococci; enterococci; penicillin-resistant strep pneumoniae
Vancomycin AE common
Red man or red neck; phlebitis to injection site; GI disturbances
Vancomycin AE occasional
Ototoxicity and nephrotoxicity (reversible)
Vancomycin AE rare
Macular rash, hematologic disturbances
Lipopeptide (daptomycin) MOA
Bind to cell membrane via Ca dependent insertion of its lipid taol; depolarization of cell membrane with K efflux and rapid cell death
Lipopeptide PK
Poor oral absorption; distributed mainly into plasma and interstitial fluid; little CNS and bone penetration; excreted in urine
Lipopeptide PD
Concentration-dependent killing: as the serum concentration is increased above MIC, bactericidal activity is also increased and at a more rapid rate
Lipopeptide uses
Vancomycin-resistant strains of s. Aureus and enterococci; alternative drug for vancomycin for treatment of MRSA bacteremia
Lipopeptide common AE
Muscle toxicity(reversible)
Lipopeptide occasional AE
Allergic pneumonitis
Polymixin MOA
Attach and disrupt bacterial cell membrane; cationic detergent; bind to anionic lps molecules leading to permeability changes in cell membrane; leakage of intracellular metabolites and nucleosides, causing cell death
Polymixin PD
Concentration-dependent killing: as the serum concentration is increased above MIC, the bactericidal activity is also increased and at a more rapid
Polymixibs uses
Infections caused by multidrug-resistant organisms like pneumonia, skin and soft tissue infections, intraabdominal infections, bacteremia
Polymixins AE common
Nephrotoxicity (reversible)
Polymixins occasional AE
Neurotoxicity, neuromuscular blockade
Polymixins AE rare
Hypersensitivity
Aminoglycosides MOA
- Block formation of the initiation complex
- Block translocation
- Misreading of the mRNA
Aminoglycosides mechanism of resistance
Inactivation by transferase enzymes; impaired entry into the cell; modification of ribosomal binding site/ribosomal protection
Aminoglycosides PK
- Very poorly absorbed from intact Gi tract
- Poorly distributed in tissues, and non-inflamed meninges except in neonates
- Excreted in urine
- Synergism with beta lactam antibiotics if given sequentially
- Antagonism with other bacteriostatic antibiotic
Aminoglycosides PD
- Concentration-dependent killing: as the serum comcentration increases above MIC, the bactericidal activity is also increased and at a more rapid rate
- Single large dose
- Post-antibiotic effect
Aminoglycosides Uses
Used in combination with beta lactam antibiotics for serious infections; not recommended as monotherapy for P. Aeruginosa; not recommended for anaerobic infections; m. Tuberculosis; contraindicated for pregnancy
Aminoglycosides AE common
Ototoxicity( irreversible); nephrotoxicity (reversible)
Aminoglycosides AE rare
Hypersensitivity, anaphylacis; loval reaction; neuromuscular blockade (results in respiratory paralysis)
Penicillin MOA
Binds with PBP causing selective inhibition of transpeptidase
Penicillin mechanism of resistance
Inactivation by beta lactamase
Penicillin drugs
Penicillin G (benzylpenicillin G) Penicillin V (phenoxymethylpenicillin)
Anti-staphylococcal penicillin
Methicillin
Naphcillin, oxacillin
Dicloxacillin, cloxacillin, flucloxacillin
Extended-spectrum penicillin
- Aminopenicillin (amoxicillin, ampicillin)
- Ureidopenicillin (piperacillin)
- Carboxylenicillin (ticarcillin, carbenicillin)
Penicillin PD
High protein binding
Highly distributed in body fluids and tissues
Poor intracellular concentrations
Urine excretion
PEnicillin PD
Time-dependent killing: efficacy is directly related to time above MIC and becomes independeny of concentration once the MiC has been reached
Penicllin G drug of choice for
Pemicillin V
1. Strep pyogenes Strep pneumoniae Non beta lactamase producing staph aureus Enterococcus faecalis Neisseria meningitidis Treponema pallidum Leptospira spp Clostridium tryani actinomyces 2. Strep pyogenes
Uses for anti staphylococcal penicillins
Methicillin-sensitive S. Aureus
Uses for aminopenicillin
Strep pneumoniae Shigella Salmonella E. Coli Listeria monocytogenes Enterococcus faecalis
Use for carboxypenicillins
Pseudomonas aeruginosa
Ureidopenicillin use
P. Aeruginosa
Protein synthesis inhibitor
Tetracyclines Glycyckine Macrolides Lincosamide Chloramphenicol Oxazolidinone Streptogramins
[tetracycline]
Short-acting 6-8 hrs
Chlortetracycline
Tetracycline
Oxytetracycline
[tetracycline]
Intermediate acting 12 hrs
Demeclocycline
Methacycline
Lymecycline
[tetracycline]
Long-acting 16-18 hours
Doxyxycline
Minocycline
[tetracycline]
Moa– most imprtant
To 30s subunit
Prevent binding of incoming charged trna unit ti the acceptor site
Efflux pump– most important
Modification of ribosomal binding site/ ribosomal protection
[tetracycline]
PK
Absorption impaired by food except long acting, antacids, dairy products, and divalent cations
High protein binding
Widely distributed
Intracellular penetration
Excreted in bile and urine except doxycycline
Pass placenta and excreted in milk
[tetracycline]
PD
Time dependent
[tetracycline]
Uses- Deoxycycline
Doc for ricketssiae
[tetracycline]
Common AE
Gi disturbance, local reaction (thrombophlebitis),
Oral candidiasis, permanent teeth discoloration and enamel hypoplasia
Bone deformity and growth retardation
[tetracycline]
Occasional AE
Hepatitis, liver failure
Photosensitivity (demeclocycline)
Esophageal ulceration
Pancreatitis (tetracycline)
Visual disturbances -tetra
Vestibular toxicity, vertigo -mino
Pseudomembranous colitis
Aggravate preexisting renal failure
[tetracycline]
Rare AE
Hypersensitivity, drug eruption
Pseudomotor cerebri
DI
Interstitial nephritis
Lupus like sydrome
Black pigmentation of thyroid
Gray pigmentation of nail, skin, sclera
[glycycline]
Tigecycline
Third gen tetracycline
[glycycline]
Moa
Bind to 30s subunit
Prevent binding of incoming charged trna unit
[glycycline]
PK
Iv
Poorly absorbed, oral
Widely distributed
Excellent intracellular penetration
Low urinary concentration
Bile and urine
[glycycline]
Uses
Infxns caused by multidrug resistant organisms– skin and soft tissue infection, intraabdominal infections
[glycycline]
AE
Same as tetracyclines- pregnancy risk category D
Hematologic disturbances
Pancreatitis
Transaminitis
Somnolence
[macrolides]
Moa
Bind to 50s subunit
Block peptide chain elongation
[macrolides]
Mechanism of resistance
- Modification of ribosomal binding site/ribosomal protection
- Efflux pump
- Production of esterases
[macrolides]
Pk-erythromycin
- Absorption impaired by food
- Widely distributed
- Good intracellular penetration
- Bile
- Pass the placenta: excreted in milk
- Inhibit cytochrome p450
[macrolides]
Pd
Time dependent
[macrolides]
Uses- erythromycin
Doc for legionella pneumophilia, mycoplasma pneumoniae, chlamydia spp.; corynebacterium spp.; bordetella pertusis
Penicillin substitute for strep pyogenes to those with allergy
[macrolides]
Common AE
Gi disturbances - diarrhea abdominal cramps due to motilin and dose related
[macrolides]
Occasinal AE
Acute cholestatic hepatitis (estolate)
Stomatitis
Thrombophlebitis
[macrolides]
Rare AE
Hypersensitivity
Infantile hypertrophic pyloric stenosis
Prolonged QT interval, arrythmia
Transient hearing loss
Pseudomembranous colitis
[clarithromycin]
Compared to erythromycin
- most active against H. Influenza amd mycobacterium avium
- longer half life
- absorption less affected by food
- urine
- less gi disturbance
[azithromycin]
Same with clarithromycin but add[macrolides]d coverage for salmonella and shigella
Doc for bartonella henselae
[azithromycin]
Compared to other macrolides
Absorptin is impaired with food
Best tissue penetratin
Concentration dpendent killing
Does not inhibit cyp450
Less gi disturbances
[lincosamide]
Clindamycin
[lincosamide]
Moa
Bind to 50s subunit
Block peptide bond formation
Block translocation
[lincosamide]
Mechanism of resistance
Modification of ribosomal binding site/ribosomal protection
Enzymatic inactivation
[lincosamide]
PD
Time dependent
[lincosamide]
PK
Absorption not affected by food
High protein binding
Good distribution to tissues
Can penetrate abscesses
Bile and urine
Cross placenta
[lincosamide]
Uses
Doc for community acquired MRSA (skin and soft tissue infection)
Anaerobic infxns above the level of the diaphragm except cns
Alternative for staph infxns
[lincosamide]
Common AE
Gi disturbances -diarrhea, nausea or vomiting
Hypersensitivity
[lincosamide]
Occasional AE
Pseudomembranous colitis, toxic megacolon
[lincosamide]
Rare AE
Esophageal ulceratin
Transaminitis, hepatitis
Hematologic disturbamces - neutropenia, thrombocytopenia
[chloramphenicol]
Moa
Bind to 50s subunit
Block peptide formation
[chloramphenicol]
MOR
Production of chloramphenicol acetyltransferase
[chloramphenicol]
PK
Available as prodrug
Low pb
Widely distributed
Good ontracellular penetration
Metab in liver
Urine and bile
Pass placenta; excreted in milk
Inhibit cyp450
[chloramphenicol]
PD
Time dependent
[chloramphenicol]
Use
Alternative drug for beta lactam
Salmonella typhi, shigella, ricketssia
[chloramphenicol]
Common AE
Dose related anemia reversible - due to inhibition of mitochondrial protein synthesis
Gray baby syndrome- due to lack pf effective glucuronic acid conjugatin
[chloramphenicol]
Occasional AE
Gi disturbances
Oral candidiasis
[chloramphenicol]
Rare AE
Aplastic anemia- idiosyncratic, irreversible
Hypersen
Peripheral neuropathy
Optic neuritis
Pseudomembranous colitis
[oxazolididone]
Linezolid
[oxazolididone]
MOa
Bind to 50s
Inhibit formatin of ribosome complex that initiates protein syntesis
No cross resistance
[oxazolididone]
PK
100% F oral
Widely distributed
Urine
Time dependent
[oxazolididone]
Uses
Multidrug resistant gram positive cocci -MRSA, VRE
[oxazolididone]
Common AE
Hematologic disturbances reversible- thrombocytopenia mostcommon, anemia, neutropenia
[oxazolididone]
Occasional AE
Gi disturbances- nausea, vomiting, diarrhea
Optic and peripheral neuropathy - mitochondrial protein symthesis, mag lead to blindness
Lactic acidosis-mitochondrial protein syn
Serotonin syndrome - fever, agitation, confusion, tremors. Diaphoresis– due to monoamine oxidase inhibition, cause hypertensive crisis; risk factors include intake with tyramine rich food, pseudohedrine, phenylpropanolamine
[streptogramins]
Srep B- quinupristin
A- dalfropristin
Synergism
[streptogramins]
MOA
Bind to 50s su unit
Interfere with peptidyl transferase -dalfo
Inhibit peptide chain elongation -quin
[streptogramins]
MOR
Modificatinof ribosomal binding site or ribosomal protection
Efflux pump
[streptogramins]
PK
Widely distributed
Excreted in stool
Inhibit cyp3A4
[streptogramins]
PD
Concentration-dependent
[streptogramins]
Uses
Infxns caused bu multidrug resistant gram positive cocci except enterococcus faecalis- skin and soft tissue infections, pneumonia, bacteremia
[streptogramins]
Common AE
Infusion related reactions
Arthralgia-myalgia syndrome
Direct hyperbilirubinemia
NUCLEIC ACID SYNTHESIS INHIBITORS
Antifolate drugs- trimethoprim - sulfamethoxazole (cotrimoxazole)
DNA Gyrase inhibitors -fluoroquinolones
[cotrimoxazole]
SMX- sulfanilamide nucleus
TMP- benzypyrimidine
Combi is bactericidal
[cotrimoxazole]
MOA smx
Smx inhibit dihydropteroate synthase- inhibit production of dihydrofolic acid
[cotrimoxazole]
Moa tmp
Inhibit dihydrofolate reductase
- inhibit prod of terahydrofolic acid
[cotrimoxazole]
Combi moa
Blocks sequential step in folic acid synthesis
[cotrimoxazole]
Smx mor
Overproduction of PABA
Overprod of dihydropteroate synthase with reduced drug binding
Impaired entry into cell
[cotrimoxazole]
Tmp mor
Overprod of dihydropteroate synthase with reduced drug binding
Impaired entry into cell
[cotrimoxazole]
PK
Widely distributed in body fluids and tissues including csf and prostate
Metabolized in the liver
Pass placenta
Excreted in urine
[cotrimoxazole]
PD
Time dependent
[cotrimoxazole]
Uses
Doc for stenotrophomonas maltophilia
Susceptible mrsa, burkholderia sepacia, salmonella, shigella, nocardia
Prostasis
[cotrimoxazole]
Common AE
Rash, exfoliative dermatitis, photosen in smx
[cotrimoxazole]
Occasinal AE
Hematologic disturbances: smx- aplastic anemia, hemolytic anemia, granulocytopenia, thrombocytopenia
Tmp: megaloblastic ane ia, leukopenia, granulocytopenia
[cotrimoxazole]
Occasional AE non hema
Kerniaterus - pregnancy risk category C – due to lack ofeffective glucuronic acid conjugation in newborn infants; not tecommended during term pregnancy and lactation, and in neonates
Urinary tact disturbamces- crystalluria, he,atueia,
Hyperkalemia
Pseudomembranous colitis
[cotrimoxazole]
Rare AE
Stevens-jh sons syndrome smx
Hepatitis, cholestasis
Cns disturbances
Methemoglobinemia
Pancreatitis
Lupus like syndrome
[fluoroquinolones]
First gen
Norfloxacin
[fluoroquinolones]
Second
Ciprofloxacin, of.oxacin, pefloxacin
[fluoroquinolones]
Trd
Levofloxacin, gatifloxacin, gemif
Oxacin, moxifloxacin
[fluoroquinolones]
MOA
Inhibit bacterial topoisomerase II(dna gyrase)- prevents relaxatin of positively superco led DNA
Inhibit topoisomerase IV- interferes with separation of replicated chromosomal DNA into respective daughter cells during cell division
[fluoroquinolones]
Mor
Modificatin of target enzyme dna gyrase
Impaired entry into the cell
[fluoroquinolones]
PK
80-95% F oral
Absorption impaired by divalent cations
Widely distributed in body fluids a d tissues including csf amd prostate
High intracellular or tissue penetration
Urine except gemi urine and bile a f moxi bile
[fluoroquinolones]
PD
Comcentration dpendent
[fluoroquinolones]
Uses
Pseudomonas aeruginosa, salmonella, shigella, e. Coli, neisseria me ingitidis
[fluoroquinolones]
Occasional AE
Gi disturbances, cns disturbances, rash, oral candidiasis, transaminitis, hepa, hematologic, hypergly in diabetics, hypogly
[fluoroquinolones]
Rare AE
Tendinitis, tendon rupture
Retinal detach,ent
Anaphylaxis
Cns disturbances
Peripheral neurpathy
Pseudomembranous colitis
Interstitial nephritis
Vasculitis
Prolonged qt interval, torsades de pointes, ventricular tach
Miscellaneous antibiotics
Metronidazole
Nitrofurantoin
Fosfomycin
[metronidazole]
moa
Nitro group reduced intracellular,y by reacting eith reduced ferredoxim
Produce toxic metabolites which are taken up into bacterial dna
[metronidazole]
PK
Oral iv rectal 100% F
Widely distributed
Penetrate abscesses including those in the brain
Urine and feces
[metronidazole]
PD
Concentratin dependent
[metronidazole]
Uses
Clostridium difficile colitis
Anaerobic infxns below the level of the diaphragm
Brain anscesses
[metronidazole]
Common AE
Gi disturbances
Dry mouth, furrytongue
[metronidazole]
Occasinal AE
Insomnia
Urethral burnimg
Darkening of urine
Phlebitis
Disulfiram like effect
[metronidazole]
Rare AE
Cns disturbances - seizure. Ata ia, dysarthria
Peripheral and optic neuropathy
Pancreatitis
[nitrofurantoin]
Moa
Rapid intracellular conversion to highly reactive intermediates by bacterial reductased
[nitrofurantoin]
PK
Well absorbed oral
Very rapid excretion in urine, no systemic antibacterial effect
[nitrofurantoin]
Use
Urinary antiseptic - uncomplicated acute cystisis)
[nitrofurantoin]
Common AE
Gi disturbances - nausea, vomiting, diarrhea
[nitrofurantoin]
Occasional AE
Neuropathy
Hemolytic anemia
Rash
Pulmonary infiltratin, fibrosis
[fosfomycin]
Moa
Inhibit the very early stage of cell wall synthesis - inhibit enolpyruvate transferase, block addition of phosphoenolpyruvatr to UDP-N-acetylglucosamine
[fosfomycin]
Pk
40% F after oral administration
Poorly distributed in tissues
Excreted in urine
[fosfomycin]
Use
Uncomplicated acute cystisis
Not for first line agent for treatment for mdr infection