What is Beta lac-tam drugs
Drug inhibits the final step of Bacteria cell wall synthesis.
These drugs bind to beta receptors and inhibits formation of cell wall
What are beta-lactom drugs
penicillins and cephalosporins -
What is penicillin
- Gram+ bacteria.
- So, take phenoxymethylpenicillin.
- Large Vd , but penetration into brain: poor, except when the meninges are inflammed.
What is board spectrum of penicillin?
Penne twin act aging Gram +
Bacteria
amoxicillin and ampicillin are more hydrophillic and therefore, are active against grambacteria.
Which drug is penicillinase resistant penicillin?
Flucloxacillin
What is penicillineage resistant pen?
By hindering access of the enzyme to beta lactam
Which bacteria increases the problem by- resisting fluclocicillin
Staph aureus
Ampicillin and amoxicillin are active against which bacteria’s?
- against non beta lactamase producing Gram + Bacteria
- also against Gram - Bacteria like e-colli, H influenza and salmonella typhimurium
Ineffective
. Against Steph aureoles, 50% E. coli, 15 %H influenza
Drug is effective against pancillinase producing organisms also inhibits beta- lactamases?
Co- anoxiclav
Indicated in respiratory and urinary tracks infection which resist to amoxicillin
Drug used for meningitis pneumonia and septicemia has same mechanism of penicillin?
Cephalosporins
What is bound spectrum of cephalosprine?.
_ Cedadroxil:-in case of antibatoral Resist
- cefuroxime:- used in sever infection against beta lactamase
- ceftazidine:- active against Gram - bacteria and less active than cefurozime agust Gram + Bacteria, used mostly aging meningitis caused by gram -ve
What is vancomycin?
How it affects Bacteria?
When it used as iv?
For which disease mostly use?
- Inhibits peptidoglycan formation.
- Active against most gram+ve organisms.
- I.v. treatment for septicemia or endocarditis caused by MRSA.
- Used for pseudomembranous colitis (super-infection of the bowel by Clostridium difficile – produces a toxin that damages the colon mucosa)
Which organ is target of antibiotics in inhibition of protein synthesis?
Ribosome is the target of antibiotics
•Aminoglycosides, binds to 30s subunit, block the translation.
. Tetracycline:. Bind to 30s subunit block attachment of tRNA
.macrolides: band to 50s subunit and prevents protein synthesis
What is amino-glycosides?
Effects which bacteria?
Side effects
Resistance
- Against many gram-ve and some gram+ve..
- Most important adverse side-effect: VIIIth cranial nerve. (ototoxicity) and kidney damage.
• Resistance – several mechanisms:
inactivation of the drug by acetylation, phosphoralation, or adenylation,
What are aminoglycosides group of drugs
Gentamicin Amikacin Neomycin netilmicin Streptomycin Rifampiein
Explain gentamicin?
Which drug is used when there is resistance agent gentamicin?
Which drug is less toxic than gentamicin?
- Gentamicin – used for acute, life-threatening gram- veinfections. Has synergism with penicillin and vancomycin and combination
- Amikacin – used for bacteria that are gentamycin -resistant.
- Netilmicin – less toxic than gentamicin
What is neomycin
Neomycin iS on aminoglycosidees drug, which inhibits synthesis of bacterial proteins.. It is too toxic, it is used tropically for skin infection and orally in order to sterilize bowel befor surgery.
Which drug is used for tb but it is too toxic?
And replaced by which drug?
- Streptomycin – active against Mycobacterium tuberculosis. But because of its ototoxicity, rifampicin replaces.
- Rifampicin – resistance develops quickly alone; so, with TB, combine with isoniazid, ethambutol, and pyrazinamide for the 1st 2 months of treatment,
Define macrolide’s?
It is subgroup drugs?
- Very safe drugs..
- Effective against gram- ve and can be used as an alternative to penicillin-sensitive patients
- Don’t cross the brain barriers – ineffective against meningitis.
- Erythromycin and clarithomycin and Azithromycin
- Erythromycin – in high doses, may cause nausea and vomiting
- Azithromycin – very long t 1/2(~40-60 hr)
Explain tetracyclines?
How they get into microorganisms?
How resistance is former?
Why they cause discolor to teeth?
- Broad-spectrum.
- Sensitive organisms accumulate it through partly passive diffusion and partly through active transport.
- Resistant organisms develop an efflux pump and do not accumulate the drug.
- Genes for tetracycliness-resistance transmitted by plasmids.
• Tetracyclines bind to Calcium in growing bones and teeth → can discolor teeth. So, should be avoided in children < 8 years old.
Explain chloramphenicol?
It is side effect?
How effects other drugs?
- large Broad-spectrum.
- Large Vd , including CNS.
- Serious side-effects: bone marrow aplasia, suppression of RBCs, WBCs, encephalopathy, optic neuritis.
- So, periodic blood counts required, specially in high doses.
- Inhibits the actions of other drugs and may increase the actions of phenytoin, sulphonlureas, and warfarin..
What’s function of flubroquinolones.?
What is function of rifamycins?
- Fluoroquinolones: inhibit enzymes that maintain the supercoiling of closed circular DNA
- Rifamycins: block prokaryotic DNAdependent RNA polymerase from initiating transcription
What is uses of trimethoprin?
What is Co- trimotarole?
. • Trimethoprin – used for UTIs and respiratory infections
. (trimethoprin + sulfamethoxazole) – used mostly for pneumonia, neo-carditis, and toxoplasmosis.
What is quinolone?
It’s function?
And it’s group off drugs?
GABA antagonists
- Inhibit DNA gyrase.
- Nalidixic acid – used only for UTIs.
- Ciprofloxin enhances its effectiveness against both gramand gram+ bacteria
Side-effects (headache, vomiting, nausea) are rare; but convulsions may occur.
