Pharm Pract Flashcards
Narrow spectrum antibacterial agents need 2 specific things
Need an accurate diagnosis
target a segment of microorganisms
Bactericidal
killing effect
bacteriostatic
stop reproduction of bacteria and rely on the immune system to handle the limited number of infective cells
Bactericidal agents
Penicillin
cephalosporins
quinolones
aminoglycosides
bacteriostatic
sulphonamides
trimethoprim
macrolides
tetracyclines
site of action of penicillin and cephalosporins
peptidoglycan cell wall
site of action nucleic acids
quinolones
site of action of sulphonamides and trimethoprin
folic acid synthesis
which bacteria work for protein synthesis
macrolides, tetracyclines, aminoglycosides, fusidic acid, chloramphenicol
complications of antibacterials
cross sensitivity
direct toxicity
hypersenitivity
superinfections eg. Candida albicans- antibacterial + probiotic-> different times
concern of overuse of antibacterials
Economic considerations
resistance
asking for product every time
unknown if killed or suppressed
choice of drug
cost efficiency of absorption spectrum of activity convenience of administration-dosage regimen adverse effects
Narrow spectrum products of penicillin vs gram +ve
Benzylpenicillin-destroyed in gastric pH-acidity in stomach
Phenoxymethulpenicillin-stable to be used orally
Example of bacterial agent that is penicillinase-resistant
Flucloxacilin
antipseudomonal penicillins
piperacilli, ticarcillin- vs gram -ve, parenterally
clasifficiation of penicillins
Natural penicillins
broad spectrum
antipseudomonal
antistaphylococcal
example of 1st,2,3 generation cephalosporins
Cefadroxil vs gram +ve cocci
Cefaclor, cefuroxime vs some gram -ve bacteria
cefotaxime- gram -ve bacteria
Macrolides affective against…
macrolides side effects…
macrolides caution…
special importancce
Gram +ve bacteria
Nausea, vomiting, gastic pain- less prominent with azithromycin and clarithromycin
Hepatic and renal impairement and predisposition to QT prolongation
Used in hypersensititvity to penicillin
what is telithromycin
a ketolide
use of telithromycin
to treat
tonsillitis, community acquired pneumonia when conventional treatment is contra indicated
sinusitis
beta-haemolytic streptococcal pharyngitis
disadvantages of telithromycin
may precipitate hepatic disorders
visual disturbance
transient loss of consciousness
used when risks is outweighed by benefit
tetracyclines are active against …
Gram -ve rickettsia mycoplasma brucella chlamydia
Tetracyclines is not to be taken with..
cautions
antacids and calcium containing products-milk
Tetracyclines are attracted to Ca, the drug attaches to Ca in bones and teeth causing impaired growth and development in children and pregnancy, also leads to dental discolouration
Pregnant women and children should not take tetracylines
Minocycline is an exception
Also contraindicated for renal disease
cautions: myasthenia gravis ad systemic lupus erythamtosus and hepatic failure
Quinolones are active against…
Gram -ve and +ve mostly -ve
Neisseria
Pseudomonas
Shigella
Quinolones vs tetracyclines
Differences:
Fluoroquinolones block GABA vs seizures
photosensitivity - may cause a skin reaction if exposed to the sun without sun screen
similarities
involved with bone development so risk for elderly and pregnant women
Caution: renal and hepatic impairment