Abx Flashcards
Prophylaxis
Prevention of disease- taking abx before surgery or procedure to prevent infection
Empiric therapy
Treatment with abx before the specific organism has been identified
Definitve therapy
abx use based on identified organism
normal flora
microorganisms that are found on specific areas of the body
colonization
growth of microorganisms in a particular body site
infection
disease caused by microorganism
Superinfection
new infection occurring in a patient who already has an infection- opportunistic infection
Contamination
introduction of pathogens into normally clean and sterile environment
bactericidal
capable of killing bacteria
bacteriostatic
inhibition or retardation of growth of bacteria with out their destruction
Susceptibility of a suspected pathogen
Determination of which abx to use based on known characteristics such as site of infection of gram status
minimum inhibitory concentration
minimum amount of abx needed to inhibit bacterial growth
minimum bactericidal concentration
minimum concentration that results in reduction in 99% of colony
susceptible
an organism that is likely to respond to treatment with drug at recommended dosage
Intermediate susceptibility
More toxic antibiotic requirted- between susceptible and resistant
moderately susceptible
abx used at higher dosage due to low toxicity or in concentrated infection
Resistant
not expected to respond to given drug irrespective of dosage and location of infection
Site of infection
clues to bacteria involved and which drugs are applicable- IE blood brain barrier, anaerobe GI site
Severity of infection
Determine dosage- IV vs oral, bactericidal or bacteristatic
Immune system
host characteristic- immunocompromised, alcoholism & DM community or hospital acquired infection
Renal function
reduction in function causes accumulation of antibiotic- monitor serum creatinine
Liver function
drugs may not be properly eliminated- erythromycin & tetracyclone
Perfusion
Poor perfusion prevents drug from getting to intended area- lower limbs of DM
age
Renal & hepatic elimination different in neonates- Young and old more vulnerable to side effects
Pregnancy
Abx cross the placenta- A, B, C, D, X- X is worst, A is best
Lactation
Abx through breastmilk- can cause detrimental effects
Narrow spectrum
isoniazid- acts against a single or limited group of microorganisms
extended spectrum
ampicillin- as a result of chemical modification acts against many groups of organisms IE- gram - & gram +
Broad spectrum
tetracycline & chloramphenicol- acts against a wide range of bacteria
bactericidal drugs
Kill bacteria- peniciilans
bacteriostatic
slow growth to a level where immune system can respond- tetracycline, sulfonamides, macrolides
Cost
patient will not pick up if too expensive
interaction
with other Rx
Synergistic inhibitory effect
sum of both drugs is greater than sum of one alone
Additive effect
therapeutic combination of two or more drugs that is equal to the sum of the individual drug
Combination therapy
- treatment of polymicrobial infections
- decrease dose related toxicity
- decreases changes of resistant microbes
- treat organism with unknown identity
Clavulanic acid
Beta lactam agonist- restores function of antibiotic by addressing resistance
Aminoglycosides- Mech of action
Ribosomal protein synthesis inhibitor- bacteriostatic- can be cidal with increased concentration
Aminoglycosides- Types
End in mycin- gentomycin, streptomycin, neomycin
Aminoglycosides- Spectrum of activity
Gram -
Including Pseudomoas aerug- severe
Synergistic with beta lactam for gram +
Aminoglycosides- routes of admin
IV, IM, Topical
Aminoglycosides- Side effects
Ototoxicity
Nephrotoxicity
Neuromuscular paralysis
Allergic rxn- skin rash
Aminoglycosides- Drug interactions
BCG, cidofovir & strptozocin
Beta Lactams
Penicillin, Cephalosporins, carbapenem & vancomycin
Penicillin- Mech of action
Inhibit cell wall synthesis leads to cell lysis
Penicillins- Names
End in cillin- penicillin G, ampicillin, amoxicillin
Penicillin- Adverse reaction
Allergy, anaphylaxis, rash
Diarrhea
Penicillins- Uses
Gram +
Streptococci
Peinicillin G, VK
Drug of choice for N Meningitis, syphilis
Ampicillin & amoxicillin
Gram +
Extended spectrum
Respiratory infections
Streptococci, enterococci
Penicillin- Resistance
Beta lactamase activity
lack peptidoglycan wall
decreased permeability
Penicillin- route of admin
Oral (before meals), IV, IM
Cephalosporins- mech of action
Beta lactam antibiotics- inhibit cell wall synthesis
1st generation cephalosporins
cephlexn, cefazolin
1st generation cephalosporin- spectrum of activity
Gram +: Strept, MSSA some Gram -: E.coli, Klebissela
skin & resp infections
2nd generation Cephalosporin- spectrum of activity
Gram +: Strept, MSSA
Gram - : Good coverage- B fragilis
2nd generation cephalosporin- drug names
cefuroxime, cefotetan, ceforitin
3rd generation cephalosporins- drug names
ceftriaxone, cefotaxime, ceftzidime
3rd generation cephalosporins- spectrum of activity
Resp & serious infections
Penetrates CSF
Gram +: Strept, MSSA
Gram - Very good- pseudomonas
4th generation cephalosporins- drugs
cefepime
4th generation cehpalosporins- spectrum of activity
Gram +: Strept, MSSA
Gram - excellent- through Pseudomondas
Cephalosporins- adverse reactions
Allergic rxn
Diarrhea
Anemia & thrombocytopenia
Seizures
Cephalosporins- Dose
Renal function changes & toxicity
Cephalosporins- Route of admin
Oral- litte difference in spectrum due to concentration
IV, IM
Monobactam- mechanism of action
Disrupt cell wall synthesis- baceriacidal
Monobactam- route of admin
IV, IM
Monobactam- drug
aztreonam
Monobactam- spectrum of activity
Gram -
Up to pseudomondas
Carbapenem- mech of action
Beta lactam- disrupt cell wall synthesis
Carbapenem- Drugs
End in penem- imipenem
Carbapenem- Adverse effects
N/V/Diarrhea
Allergy- penicillin
seizures
Carbapenem- Spectrum of action
Broad- severe infections
Gram +: Strept, MSSA
Gram - psuedomonas
Anarobes
Carbapenem- Route of admin
IV or IM
penetrate CSF
Vancomycin- Mech of action
Inhibits cell wall synthesis- beta lactam
Vancomycin- Spectrum of activity
Drug of choice for MRSA
Strept, Staph, Entero
No Gram -
Vancomycin- Adverse effects
Red-man syndrome
Nephrotoxicity
Ototoxicity
Vancomycin- Drug interactions
BCG live, cidofovir, streptozocin
Macrolides- drugs
erythromycin, clarithromycin, azithromycin
Macrolides- Mech of activity
Ribosomal inhibition- bacteriostatic
Macrolide- Spectrum of activity
Gram +
Chlamydia & syphallis
Atypical respiratory infections: Legionella, pneumoniae
Macrolides- Adverse Rxn
N/V/diarrhea
Phlebitis
Prolonged QT interval
Macrolides- Drug interactions
lots! CYP 450 fluconozole, lovastatin,
Tetracyclines- Drugs
end in cycline- doxycycline, tetracycline, mincycline
Tetracycline- Mech of action
Ribosomal protein synthesis inhibitor- bacteriostatic
Tetracycline- spectrum of activity
Gram + strept & MSSA
Weak Gram -
A typical respiratory infections
Tetracycline- adverse reactions
Photosensativity
N/V/D
Toothdiscoloration
Quinolones- Drugs
“floxacin”
ciprofloxacin, norfloxacin
Quinolones- Mech of action
Inhibit DNA synthesis- bacteriostatic
Quinolones- Spectrum of activity
Gram -
Some Gram +
Atypical respiratory infections
Quinolones- adverse reactions
Nausea, dizziness, headache, insomnia
Quinolones- Drug interactions
Oral binding with cations- Ca, Fe, Antacids
Sulfa Drugs
Trimethoprim-sulfamethoxazole
Sulfa- Mech of action
Inhibit folic acid synthesis- formation of essential cofactor- bacteriostatic
Sulfa- Spectrum of activity
Gram + Strept, MSSA
Gram - Enterobacteriacae
Sulfa- Adverse reactions
Allergic- rash
N/V/D
kernicterus
Neutropenia, thrombocytopnea
Sulfa- Drug interactions
Warfarin
Anaerobic agents
Clindamycin, metronidazole, chloramphenicol
Anaerobic- mech of action
Inhibition of ribosome- bacteriostatic
Sulfa- Route of admin
oral, IV, topical, suppositories
