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Antibiotics
Pharm Antibiotics
Front | Back |
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Beta Lactam anti biotics | Workd by covalently binding the active site of a transpeptidase enzyme |
Beta lactams are bacteri---- | Bactericidal |
Transpeptdase Enzymes | Catalyze the cross-linking reaction on PG polymers in synthesis of bacterial cell wall |
Beta lactam's selective toxicity due to | Mammalian cells not having cell wall. |
Baeta Lactams act only on | cells which are growing and synthesizing new cell wall material |
Beta Lactam Antibiotics Include | Penicillins, cephalosporins, carbapenems |
Penicillin | -Most allergenic of all antibiotcs. -All penicillins, new or old, are cross-sensitizing and cross reacting |
Penicillin undesirable properties | -rapid excretion -bacterial resistance - S. aureus penicillinase elaboration makes it resistanct to nearly all penicillins except methicillin-type penicillins -Strep viridans has some resistant strains |
problem of penicillin therapy | Hypersensitivity reactions. -resistance development. |
Penicillin drug interactions | bacteriostatic antibiotics. -oral contraceptives(decreases effectiveness of all oral contraceptives). |
Penicillin Derivatives | Penicillin G -Benzathine penicillin G -procaine penicillin G -Penicillin V |
Penicillin G antibacterial spectrum: | gram +, Neisserai spp., Some anaerobes |
Penicillin G administered via | parenteral route |
Uses of Penicillin G | beta-hemolytic strep, inf. w/pneumococci, meningococcal inf., syphilis, inf. by B. anthracis, other gram + inf. |
characteristics of Pen. G | acid labile, Poor absorption after oral administration, dosage measured in units-1600units/mg |
Benzathine Pen G. use | used for prolonged effects for beta-hemolytic strep. inf. ("strep throat"), Syphylis, other gram + inf. |
Benzathing Pen G also | are repository forms of Penicillin G. _lower, sustained blood levels |
Procaine Pen. G also | repository forms of PenG. -lower, sustained blood levers. |
Penicillin V antibacterial spectrum: | Only gram + aerobes and some anaerobes |
Penicillin V administered via | Oral route |
Penicillin V is... | Bactericidal. -Acid stable |
Penicillin G | 1st penicillin discovered and used (alexander fleming, 1929) |
Penicillinase Resistant Penicillins | Methicillin, Cloxacillin, Oxacillin, Naficillin, Dicloxacillin |
Which are Acid Unstable | Methicillin |
Which are Acid Stable | Cloxacillin, Oxacillin, Naficillin, Dicloxacillin |
Methicillin used for | S. aureaus treatment |
#1 drug used in Hospitals | Methicillin |
Extended Spectrum Penicillins | Ampicillin, Amoxicillin, Amoxicillin/Clavulanic acid |
Extended Spectrum Penicillins have | broader spectrun than penicillin V |
Extended Spectrum Penicillins used for | gram - and gram + organisms |
amoxicillin and ampicillin used for | gram + & - aerobes and most oral anaerobes |
Extended Stectrum Antibiotics: Amoxicillin and Ampicillin have a greater propensity to cause | super-infections |
Amoxicillin and ampicillin are also active against | S. pyogenes, S. pnueumoniae, H. influenzae, Enterobacteriaceae, E.coli, and L. monocytogenes(menigitis) |
Why is resistance becoming a problem with amp and amox. | due to excessive use. Amox is #1 prescribed in US |
2 drugs adequately absorbed ad ter oral administration | Amoxicillin and Ampicillin |
Absorption reduced with food in | Ampicillin |
good absortption after oral administration even with food | Amoxicillin |
Why combine Amox or Amp with Clavulanic acid | it protects the antibiotics from penicillinase produced by Staphylococci |
Specific Purpose penicillins are | Ticarcillin, Piperacillin, Aztocillin, Mezlocillin |
relatively non toxic antibiotic of specific purpose | Ticarcillin |
Ticarcillin's use is | reserved for serious infections of Pseudomonas ssp. and Indole positive proteus ssp. |
anti-pseudomonas penicillins | piperacillin, Axlocillin, Mexlocillin |
for Ticarcillin you must | test bacterial susceptibility due to large variations in sensitivity of various strains of pseudomonas and proteus |