Pharm Exam 2
Terms
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- Penicillin G
- Spectrum: Primarily gram + bacteria. May be used on gram - Selective toxicity: Attacks cell walls. Human cells do not have cell walls Resistance: susceptible to B-lactamase Side effects: allergic reactions. Immediate is most severe. Symptoms include Pruritus (itch), erythema, rhinitis, hypotension, shock. Can potentially be fatal. Delayed reaction occurs over 3 days later, symptoms include acute swelling of tongue (glossitis) or discoloration of tongue to brown or black
- Nafcillin
- B-lactamase resistant penicillin derivative. Resistant to staphylococcal penicillinase. Spectrum: same as penicillin G Selective Toxicity: Human cells do not have cell walls Resistance: structural variance in PBPs alter affinity
- Methicillin
- B-lactamase resistant penicillin derivative. Resistant to staphylococcal penicillinase. Spectrum: same as penicillin G Selective Toxicity: Human cells do not have cell walls Resistance: structural variance in PBPs alter affinity
- Amoxicillin
- Expanded spectrum penicillin derivative. Spectrum: improved activity against gram-positive and gram-negative relative to natural penicillins Selective Toxicity: Human cells do not have cell walls Resistance: Susceptible to B-lactamase
- cefotaxime
- 3rd generation cephalosporin (very good at penetrating blood-brain barrier) Spectrum: Extended (beyond other cephalosporins) gram - activity, resistant to some bacterias B-lactamase Selective toxicity: Very high degree of selective toxicity. Targets cell walls, which human cells do not have. Resistance: inactivation of the b-lactam ring by cephalosporinases, decreased permeability of the cell wall, alterations in PBPs resulting in diminished affinity Side effects: hypersensitive reactions, similar to penicillins
- ceftriaxone
- 3rd generation cephalosporin (very good at penetrating blood-brain barrier) Spectrum: Extended (beyond other cephalosporins) gram - activity, resistant to some bacterias B-lactamase Selective toxicity: Very high degree of selective toxicity. Targets cell walls, which human cells do not have. Resistance: inactivation of the b-lactam ring by cephalosporinases, decreased permeability of the cell wall, alterations in PBPs resulting in diminished affinity Side effects: hypersensitive reactions, similar to penicillins
- meropenem
- What is it: alternative B-lactam antibiotic (often co-administered with aminoglycosides) Spectrum: very broad, active against gram - and gram + bacteria Selective toxicity: all B-lactams have selective toxicity due to cell-walls Resistance: may induce B-lactamases
- vancomycin
- What is it: alternative antibiotic that does not have a B-lactam ring Spectrum: only for gram + bacteria that do not respond to B-lactams Selective toxicity: Binds to specific sequence in cell-wall sequence of bacteria Resistance: vanA gene complex produces an abnormal PBP that cannot be bound by vancomycin Side effects: hypersensitivity, tachycardia and hypotension, 20% of patients will have kidney damage
- azithromycin
- What is it: macrolide Spectrum: extended spectrum, very active against gram+ bacteria as well as some gram -; bacteriostatic Selective toxicity: inhibits translocation of tRNA in ribosomes, ribosomal subunits are different in humans Resistance: efflux pumps and alteration of target (from Wikipedia, not lecture) Side effects: diarrhea, nausea, abdominal pain (Wikipedia)
- clindamycin
- What is it: bacteriostatic inhibitor of ribosomal function Spectrum: broad, activity against both gram + and gram - bacteria Selective toxicity: Ribosomal subunits in bacteria are different than human subunits Side effects: C. Diff superinfection
- tetracycline
- What is it: bacteriostatic inhibitor of ribosomal function Spectrum: broad, very active against gram + and gram - bacteria Selective toxicity: target ribosome subunits are different from human ribosome subunits Resistance: efflux pump tetracyline out of cell (from Wikipedia, not lecture) Side effects: inhibits bone growth, permanent discoloration of teeth, can lead to superinfection
- gentamicin
- What is it: aminoglycocide (Bactericidal) Spectrum: aerobic gram - bacteria, gram + activity with B-lactam Selective toxicity: binds to subunit of ribosome, this subunit is not in huan cells. Selective toxicity is not that high Side effects: toxic to sensory cells of ear, toxic to kidney (damage in 8-20% of patients)
- metronidazole
- Type: Bactericidal and Concentration dependant What is it: Inhibitor of DNA integrity. Reduction of metronidazole creates free radicals which are cytotoxic. Reduced form of metronidazole reacts with DNA producing DNA strand breakage. Spectrum: Broad Spectrum: Anaerobic gram-positive and gram negative. Selective toxicity: Activation (reduction) only occurs in anaerobic bacteria. Resistance: Side effects: Nausea, potential carcinogenic effects: avoid alcohol due to disulfiram-like effects
- ciprofloxacin
- Bactericidal What is it: Second generation Quinolone (binds to DNA gyrase which controls the relaxation of supercoiled DNA) Spectrum: Primary effective against aerobic gram - Selective toxicity: Eukaryotic cells have a similar but not identical enzyme Resistance:mutations in DNA gyrase Side effects: Can destroy cartilage in young people: use with caution in children under 17 or during pregnancy.
- sulfamethoxazole
- Type: Bacteriostatic What is it: Dihydropteroate synthetase inhibitor (prevents conversion of PABA to dihydropteroic acid, necessary to synthesize DNA) Spectrum: Broad Spectrum antibiotics Selective toxicity: We do not need to synthesize dihydropteroic acid Resistance: Increase synthesis of PABA (70x); Altered synthetic pathway; metabolism of the drug; Resistant form of dihydropteroate synthetase Side effects: none Synergistic activity w/ trimethoprim
- trimethoprim
- Type: Bacteriostatic What is it: Inhibits dihydrofolate reductase (which changes dihydrofolic acid into tetrahydrofolic acid,in the pathway to synthesize DNA Spectrum: Broadspectrum Selective toxicity: Bacterial enzyme is sufficiently different from ours (10,000x affinity) Resistance: increase synthesis of precursor, altered synthetic pathway, metabolism of the drug, resistant form of enzyme Side effects: None given
- rifampin
- Type: Bactericidal What is it: Binds to Beta subunit of bacterial RNA polymerases (inhibits DNA Transcription) Spectrum: Broad Spectrum Selective toxicity: Much lower affinity for eukaryotic RNA polymerase Resistance: Altered RNA polymerases with modified beta subunits Side effects: Inhibits oral contraceptives!!!!!! Hepatotoxicity, Discolors saliva, urine, tears (reddish color) Note: Use is restricted to tuberculosis and a few other indications due to a rapid emergence of resistance
- isoniazid
- What is it: Inhibitor of fatty acid synthatase II needed to yield mycolic acid Spectrum: Targets mycobacteria only. Ineffective against gram-/gram+ bacteria Selective toxicity: Prodrug activated only by mycobacteria enzymes. Catalase-peroxidase activates isoniazid. Resistance:Approximately 1 in 1,000,000 are resistant. Infections typically involve more than 100,000,000 bacteria. Mutants will be selected if treatment involves isoniazid alone. Side effects: Hepatotoxicity