bacterial protein synthesis inhibitors
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- what are the broad spectrum inhibitors?
- chloramphenicol and tetracyclines
- what are the moderate spectrum?
- macrolides
- what are the narrow spectrum?
- lincosamides, streptogramins, and linezolid
- what is the proto for chloramphenicols?
- chloramphenicol
- what is the proto for tetracyclin?
- tetracycline with variants democlocycline, doxycycline, minocycline, clarithromycin
- what is the proto of macrolides?
- erthromycin, with varients azithromycin, clarithromycin
- proto of lincosamides
- linomycin with variant clindamycin
- proto of streptogramins?
- quinupristine-dalfopristin
- proto of oxazoladinones
- linezolid
- what binds close to the 50S subunit? and bacteriostatic
- chloramphenicols, clyndamycin, and macrolides
- which blocks the charged tRNA molecule from binding to the acceptor site on the ribosome mRNA complex?
- chloramphenicol
- what blocks translocation from the acceptor site to the donor site?
- macrolides and clindamycin
- what blocks formation of the initiation complex?
- macrolides
- what binds to the 30s subunit at a site that blocks charged tRNA to the acceptor site?
- tetracyclines
- what binds to the 50s subunit, not permitting the exit?
- streptogramins
- what inhibits initiation by blocking formation of the tRNA ribosome mRNA ternary complex?
- linezolid, by binding to the 50S
- what can chloramphenicol affect?
- mito ribosomes since they contain 70S rRNA.
- can chloramphenical readily cross the placenta and bbb?
- yes
- what are suseptible to chloram?
- strains of h. influenza, N. meningitidis and bacteroids and for these the drug maybe cidal.
- how is resistance formed?
- plasmid mediated, occurs through the formation of acetlytransferases that inactivate the drug
- common use of chloram is ?
- topical agent
- back up for severe infections caused by
- salmonella, and pnuemococcal and meningococcal meningitis in beta-lac resistant individuals. can also be used for ricketsial ds. and for anearobe infections
- what can occur with chloram?
- superinfection with candidiasis
- what occurs in the bone marrow?
- inhibition of red cell maturation leading to decrease in circulatong RBC´s..this is dose dependant and reversible. aplastic anemia is rare and fatal.
- gray baby syndrome?
- infants characterized by cyanosis and cardiovascular collapse. neonates are deficient in hepatic glucuronosyltransferase, the enzyme required for chloramphenical elimination.
- drug interaction with?
- phenytoin, coumarins, tolbutamide
- what can impair the availability of tetracyclins?
- multivalent cations (calcium, iron, aluminim) and food. can cross the placental barrier
- tetras activity against?
- g+ and g-, rickettsia, chlamydia, mycoplasma and some protozoa
- resistance is mediated?
- plasmid
- uses of tetra are?
- DOG for infections of mycoplasma pnuemonia in adults, chlymidia, rickettsia, and vibrios and alternative for syphilis, and resp. tract infections and profilaxis in chronic bronchitis and acne.
- specific uses are for?
- h. pylori, doxycycline for limes ds. minocycline for meningococcal carier state.
- which is used for the prevention of malaria and in the treatment of amebiasis?
- doxy
- which is used to manage ADH secreting tumors?
- demeclocycline which inhibits the renal action of ADH
- toxicity
- possible life threatening colitis, mild nausea, the D, can lead to candidiasis (oral and vaginal) and possible super infection with c. dificile or s. aureas.
- affects what in the fetus?
- tooth enamal dysplacia and irregularities in bone growth. not indicated during pregnancy and can cause problems in the teeth of younger children, miscoloring, and crown deformation.
- can cause what in patients with hepatic problems and in pregnacy?
- hepatic necrosis
- what syndrom can be caused?
- (Fanconi´s syndrom, renal tubular acidosis)......demeclocycline may enhance skin sensativity to UV light..fotosensitivity....can cause dose dep. reversible dizziness and vertigo with doxy and mino.
- with what drug are high levels achieved in tissues and in phagocytes 10 to 100 times higher than in plasma?
- azithromycin
- what is active against, campylobacter, chlymidia, mycoplasma, legionella, g+coci, and some g-organisms.
- erythromocycin, with asi and clari having greater activitiy against chlymidia, M.avium and toxoplasma.
- resitance in g+ is due to what?
- production of methylase that adds a methyl group
- which is extended for h.influenza, m. catarrhalis, and neisseria and for community aquired pnuemonia
- azithromycin
- treats m. avium complex, and in the regimine for ulcers?
- claritho
- adverse effects?
-
skin rashes, GI irritation, eosinophilia
erythromycin can cause hypersensetivity based acute cholestatic hepatitis - what can erythromycin increase?
- anticoagulants, carbamazepine, cisapride, digoxin, theophyline, due to p450 inhibition. cardiac arythmias can occur when taking aztemizole
- does azithro inhibit p450?
- no
- what is the use of clindamycin?
- severe infections due to certain anearobes such as bacteroides. recommended for prophylaxis of endocarditis in vascular ds. patients with peni allergies. also affective against, p.carinii and t. gondii
- what are some of the toxicities of clinda?
- neutropenia, hepatic dysfunction, possible superinfection with c.difficile psuedomembranos colitis.
- streptogramins
- half life longer combined than alone. used for MRSA and VRSA and resistant enterococcus faecium.
- what can they cause?
- pain and arthralgia-myalgia syndrome and are potent inhibitors of CYP3A4 and increase plasma levels of cisapride, diazapem, warfarin
- what is the new antibx?
- linezolid acative against g+cocci, including stains resitant to beta lactams and vancomycin.