anti-infectives Flashcards
what indicates response to anti-infective therapy?
reduced fever
normal white blood count
improved appetite
absence of symptoms such as cough
how are anti-infective drugs known as commonly?
antibacterial
antimicrobial
antibiotic
antifungal
what are the ways anti-infective drugs are classified?
chemical structures
mechanism of action
actions of anti-infective drugs
affect target organism’s structure, metabolism, or life cycle
goal is to eliminate pathogens.
what is the difference between bactericidal and bacteriostatic?
bactericidal = kill bacteria bacteriostatic = slow growth of bacteria
drug classes for treating bacterial infections
penicillins cephalosporins tetracyclines macrolides aminoglycosides fluoroquinolones sulfonamides miscelaneous antibacterials
penacilins
end in icillin….and there are a ton.
the “A”s are all BROAD and are aminopenicillins
the various penacilins are narrow and pencillinase sensitive …the penicillinase resistant narrow sepctrum are cloxacillin and didoxacillin.
extended spectrum are piperalcillins, carbenicillin and ticarcillin
therapeutic action of penicillin
most effective against gram-positive bacteria
kill bacteria by disrupting cell wall with betalactam ring
beta-lactamase or penicillinase is an enzyme allowing bacteria to be resistant
newer drugs are penicillinase resistant
combination drugs with beta-lactamase inhibitors!
penicillin G potassium
kills bacteria by disrupting their cell walls
primary use is streptococci, pneumococci, staphylococci, gonorrhea and syphilis treatment
adverse effects include anaphylaxis, diarrhea, nausea, vomitting, pain at injection site, superinfections, drug interactions
Cephalosporins
all are ceph or cef
there are four generations
therapeutic action of cephalosporins
similar in structure and function to penicillins
have beta-lactam ring; are bactericidal
widely prescribed anti-infective class
more than 20 cephalosporins are availableg
cross sensitivity with penicillins
classified by generations
what is the difference between the generations of cephalosporins?
first generation is oldest. bacteria producing beta-lactamase are resistant
second are more portent, broader spectrum, more resistant to beta-lactamase
third are longer in duration of action with an even broader spectrum. they are resistant to beta-lactamase
fourth generation is effective on organisms resistant to earlier generations
third and fourth capable of entering CSF
cefotaxime
cephalosporin prototype.
3rd generation
inhibits cell wall synthesis
primarily used for broad spectrum activity against gram-negative organisms; for serious infections of the lower respiratory tract, CNS, genitourinary system, bones, blood and joints
adverse effects are hypersensitivity, rash, itching, anaphylaxis, diarrhea, vomitting, nausea, pain at injection site, drug interactions
Do cephalosporince affect prothrombin
yes, they may
tetracyclines
demeclocycline
doxycycline
minocycline
tetracycline
therapeutic action of tetracyclines
some of broadest spectrums of any antibiotic class
large number of resistant bacterial strains
drug of choice for only a few diseases: rocky mountain spotted fever, typhus, cholera, lyme disease, peptic ulcers, chlamydial infections
inhibit bacterial protein synthesis with bacteriostatic effect
tetracycline
prototype of tetracycline
is broad-spectrum, effective against a broad range of gram positive and negative bacteria
primarily used for chlamydiae, rickettsiae, and mycoplasma
adverse effects are superinfections, nausea, vomitting, epigastric burning, diarrhea, discoloration of teeth, photosensitivity, drug interactions
not for pregnant or lactating women…damages linear skeletal growth of tiny person…not for kids under 8 either
decrease effectiveness of oral contraceptives
don’t take with milk products, iron supps, magnesium containing laxatives or antacids.
macrolides
azithromycin
clarithromycin
erythromycin
therapeutic action of macrolides
safe alternatives to penicillin
effective against most gram positve and negative bacteria
inhibit protein synthesis by binding to bacterial ribosome
bacteriostatic at low doses and bacterocidal at high doses
drug of choice for whooping cough and legionnaire’s disease. used for infections caused by mycoplasma pneumoniae, streptococcus, h.influenz, chlamydia
broad spectrum, no superinfections may occur
erythromycin
prototype macrolide anti-infective
acts as spectrum similar to penicillins
effective against gram positive bacteria
preferred drug for whooping cough (bordetella pertussis)
cornebacterium diphtheria
adverse effects are hepatotoxicity, nausea, abdominal cramping, and vomitting
aminoglycosides
gentamicin
neomycin
streptomycin
tobramycin
therapeutic action of aminoglycosides
narrow spectrum
bactericidal, inhibit bacterial protein synthesis
reserved for serious systemic infections caused by aerobic gram negative bacteria (e.coli, serratia, proteus, klebsiella, and pseudomonas)
why are aminoglycosides used under careful monitoring?
they have much more serious side effects than other antiinfectives/antibiotics
can cause ototoxicity(toxic to ear), nephrotoxicity (poisonus to kidney), neuromuscular blockade
gentamicin
aminoglycoside, anti-infective
broad-spectrum, bactericidal
primarily used for serious urinary ,respirator, nervous or GI infections
often used parenterally or in eyedrops and used in combination with antibiotics
adverse effects are ototoxicity and nephrotoxicity
fluoroquinolones
they are anti-infectives
first gen: cinoxacin
second gen: ciprofloxacin
norofloxacinth
ofloxacin
third gen: levofloxacin
fourth gen: gemifloxacin
moxifloxacin
therapeutic action of fluoroquinolones
are bactericidal and affect dna synthesis by inhibiting two bacterial enzymes
all have activity against gram-negative pathogents
newer drug classes have activity against gram-positive microbes
ciprofloxacin
an anti-infective; a fluoroquinolone
inhibits bacterial dna gyrase; effects bacterial replication and dna repair
primarily used for respiratory infections, bone and joint infections, GI infections, ophthalmic infections, sinusitis, prostatitis
adverse effects in GI system, headaches, dizziness, and drug interactions
need to monitor white blood count
what may norfloxacin, a fluoroquinolone anti-infective, cause?
photophobia
what can fluoroquinolone, an anti-infective drug class, affect, especially in children?
tendons
Sulfonamides
sulfacetamide
sulfamethoxazole
sulfsoxazole
trimethoprim
therapeutic action of sulfonamides
are bacteriostatic and act by inhibiting folic acid
are broad spectrum
widspread use leads to resistance
use in combination to treat UTIs
used to treat pneumocytis carinii and shigella
anti-inflammatory properties can help with rheumatoid arthritis and ulcerative colitis
trimethoprim-sulfamethoxazole
a sulfonamide, anti-infective
kills bacteria by inhibiting bacterial metabolism of folic acid
primarily used to treat UTIs, pneumocytis carinii pneumondia, shigella, and bronchitis
adverse effects are skin rashes, nausea, vomiting, agranulocytosis or thrombocytopenia, causes photosensitvity
can induce steven-johnson syndrome, a skin abnormality
Vancomycin
is a miscellaneous anti-infective
bactericidal, inhibits cell wall synthesis
primarily used for and reserved for severe or resistant gram positive infections
EFFECTIVE FOR MRSA INFECTIONS!
adverse effects are ototoxicity, nephrotoxicity, red man syndrome and anaphylaxis
which anti-infectives inhibit rna synthesis?
rifampin
which anti-infectives inhibit cell wall synthesis
penicillins
cephalosporins
vancomycin
isoniazide
which anti-infectives inhibit dna synthesis
fluoroquinolones
which anti-infectives inhibit metabolites?
sulfonamides
which anti-infectives are protein synthesis inhibitors
macrolides aminoglycosides tetracyclines clindamycin chloramphenicol
what are super infections?
are secondary infections that occur when too many host flora are killed by an antibiotic
host flora prevented growth of pathogenic organisms by out competing it and producing antibacterial substances
signs and symptoms include diarrhea, bladder pain, painful urination, abnormal vaginal discharge
Antituberculosis drugs
first line: ethambutol isoniazid pyrazinamide ciprofloxacin rifampin rifater streptomycin
second line agents amikacin ciprofloxacin kanamycin ofloxacin
what is TB caused by?
mycobacterium tuberculosis
usually invades the lung, may enter other systems
immune response attempts to isolate TB by walling it off and so TB can be dormant for a life time in walled-off areas called tubercles OR can reactivate when immune system is suppressed
how is TB different from other infections?
mycobacteria have a cell wall resistant to penetration by anti-infective drugs
at least two and up to four antibiotics are given concurrently
the drugs prevent and treat TB
pharmacotherapy of TB
multidrug therapy, 2-4 administered concurrently
different combinations during course of therapy. this is required because mycobacterium grows slowly and is commonly resistant
what is chemoprophylaxis and when is it used?
an antituberculosis drug used to prevent TB in high-risk populations (those close to someone with TB, those with AIDS, HIV or receiving immunosuppresent drugs
For whom is antituberculosis therapy contraindicated?
those with AIDS, liver disease, kidney disease
used with caution in those with renal failure, pregnant or lactating or a history of convulsive disorders
isoniazid
an antituberculosis drug
bactericidal for active organisms, bacteriostatic for dormant mycobacteria
drug of choice for TB
adverse effects are numbness of hands and feet, rash, fever and rarely hepatotoxicity
