- include beta-lactam ring in their structure
- reach bone, csf, cns in inflam (meningitis), pass placenta & breast milk
- excreted actively (probenecid)
include:
*natural p :
1- benzyl p (p g)
1- benzyl p (p g)
-(g + cocci, g- cocci , g+bacilli , spirochetes)
- i/m , depot
2- phenoxymethyl p (p v)
-more acid stable
-spectrum samepg + some anaerobic microorganism
- orally
*anti staphylococcal penicillins
methicillin , nafcilin, oxacillin, dicloxacillin
-penicillinase resistant p
-staphylococci
-methcillin used in lab only ,toxic
- absorption decreased by food in stomach
- destructed by acid so given 30-60 min before meal
- nafcilin biliary exc
*extend spectrum p
ampicillin , amoxicillin
-are acid stable
- spectrum same pg + g- bacilli
-ampicillin choiced for g+bacilli( listeria monocytogens)
-treatment of respiratory infection
-combination with beta lactamase inhibitor (clavulanic acid +amoxicillin &
sulbactam+ ampicillin) protect them from enzymatic hydrolysis & extend
spectrum
- sulbactam+ ampicillin (i/v, i/m)
- amoxicillin ,clavulanic acid +amoxicillin (oral)
*anti pseudomonal p
-carboxy p (carbenicillin, ticarcillin)
-uridop ( piperacillin)
- against p. aeruginosa , g-bacilli (but not klebsiella)
- piperacillin most potent
-all are acid stable
-ticarcillin, piperacillin combined with ((clavulanic acid & tazobactam))
respectively increase spectrum to include pencillinase producing mo
- the combination given i/v , i/m because they acid unstable
adverse effect:
- hypersensitivity (due to its metabolite)
- diarrhea (changes in normal balance of intestinal mo)
- nephritis
- neurotoxicity ( irritate neuronal tissue)
- hematologic toxicities: decrease coagulation with antipseudomonal
- cation toxicity ps administered as na or k salts high conc of them cause
toxicity
uses of pen g:
preparation as procaine , benzathine to delay absorption
preparation as procaine , benzathine to delay absorption
- pneumonia
- syphilis
- gonorrhea
- clostridium ( anaerobic)
- anthrax
- diphtheria
- endocarditis
uses of amoxicillin:
-uti
-otitis
-meningitis
-pen resistant pneumococci
uses of ampicillin:
-shigellosis
-shigellosis
-listeria monocytogens
-e coli
-haemophilus influenzae
- salmonella typhi
uses of antipseudomonal
-e coli
-haemophilus influenzae
-enterobacter spp
-proteus ( indol positive)
cephalosporin:
- arebeta-lactam antibiotic, semi synthetic
- structurally & functionally related to pen
- same moa
- more resistant to beta-lactamase
- all pass placenta
1st generation:
cephalexin (oral, in pharyngitis,uti, respiratory infection )
cefazoline (parenteral , penetrate bone ) cefadroxil (oral, uti)
spectrum: s aureus , s epidermidis streptococcus pneumonia ,
st pyogenes anaerobic streptococci e coli klebsiella pneumoniae proteus
morabilis
2nd generation: weak against g+ cocci
-cefaclor oral
-cefprozil
-cefuroxime na ( parenteral, pass bbb, used in community acqin uired
pneumonia, in septicaemia )
-cefuroxime axetil: (oral, against ?-lactamase producing mo)
-cefoxitin: parenteral, in pelvic inflammatory disease, in gynecologic sepsis,
intra-abdominal sepses
streptococcus pneumonia , st pyogenes, anaerobic streptococci n gonorrheae
g- cocci, g- rods haemophilus influenzae
klebsiella pneumoniae , proteus morabilis, enterobacter aerogenes
3rd generation ceftriaxone , cefotaxime, ceftazidime ceftizoxime , cefdinir ,
ceftibuten, cefixime
-g- rods +neiseria gonorrhea+ enteric mo+ serratia
*ceftriaxone or cefotaxime :1st choice for meningitis
*ceftazidime: act against p aurogenosa ,reach csf cefdinir ,
cefixime: oral
cefotaxime : parenteral , reach csf,