Flashcards
antibiotics drug list Pharm 4
Flashcards do conjunto (39)
- 1AmoxicillinPenicillin (beta lactam)
*BACTERICIDAL*
Interferes with cell wall peptidoglycan synthesis by binding to penicillin binding receptors leading to cell lysis and death.
Moderate Spectrum - 2Chloramphenicol*BACTERIOSTATIC*
Inhibits protein synthesis, prevents chain elongation by inhibiting peptidyl transferase activity
Broad Spectrum - 3CiprofloxacinQuinolones
*BACTERICIDAL*
Inhibits bacterial DNA synthesis by blocking DNA gyrase and topoisomerase IV.
Broad Spectrum - 4CephalexinCephalosporin
(beta lactam)
*BACTERICIDAL*
Interferes with cell wall peptidoglycan synthesis by binding to penicillin binding receptors leading to cell lysis and death.
Moderate Spectrum - 5CeftriaxoneCephalosporin
(beta lactam)
*BACTERICIDAL*
Interferes with cell wall peptidoglycan synthesis by binding to penicillin binding receptors leading to cell lysis and death.
Broad Spectrum, - 6ClarithromycinMacrolide
*BACTERIOSTATIC*
Inhibits protein synthesis by binding to 50S ribosomal subunit - 7DaptomycinDaptomycin
*BACTERICIDAL*
This cyclic lipopeptide inserts into Gram-positive bacterial cytoplasmic membranes in the presence of calcium. This causes depolarisation, leading to potassium efflux, consequently impairing potassium dependent synthesis of DNA, RNA and protein. This leads to cell death.
Narrow spectrum against Gram-positive bacteria. - 8DoxycylineTetracycline
*BACTERIOSTATIC*
Inhibits bacterial protein synthesis by reversibly binding to 30S ribosomal subunit
Broad Spectrum, - 9D-CycloserineCycloserine
*BACTERICIDAL OR BACTERIOSTATIC*
interferes with bacterial cell wall synthesis by inhibiting conversion of L-alanine to D-alanine. Against tuberculosis.
Broad Spectrum - 10GentamicinAminoglycosides
*BACTERICIDAL* (concentration dependent)
Irreversibly binds to the 30S ribosomal subunit, leading to inhibition of protein synthesis and cell membrane damage.
CF + Gram-negative infections - 11IsoniazidIsoniazid
*BACTERICIDAL* against actively dividing tuberculosis
*BACTERIOSTATIC* against resting tuberculosis
Inhibits synthesis of mycolic acid, constituents of bacterial cell wall. Rifampicin increases activity of Isoniazid and is often used in combination. - 12MeropenemCarbapenem
*BACTERICIDAL*
Inhibits bacterial cell wall synthesis by binding to penicillin binding proteins - 13MethicillinPenicillin (beta lactam)
*BACTERICIDAL*
Inhibits bacterial cell wall synthesis by inhibiting cross-linkage between the linear peptidoglycan chains that make up a major component of the cell wall of Gram-positive bacteria; it does so by binding to and competitively inhibiting transpeptidase.
Penicillase resistant
narrow spectrum - 14RifampicinRifamycins
*BACTERICIDAL*
Inhibits bacterial RNA polymerase, increases action of Isoniazid used in combination - 15StreptomycinAminoglycoside
*BACTERICIDAL*
against tuberculosis - 16Sulphanilamide*BACTERICIDAL*
Competitively inhibiting enzymatic reactions involving para-aminobenzoic acid (PABA). PABA is needed in enzymatic reactions that produce folic acid, which acts as a coenzyme in the synthesis of purines and pyrimidines. Mammals do not synthesize their own folic acid so are unaffected by PABA inhibitors, which selectively kill bacteria. - 17TetracyclineTetracycline
*BACTERIOSTATIC*
Inhibits bacterial protein synthesis by binding to the 30S subunit of the ribosome
Only used for specialised applications due to widespread resistance. Cannot be used in young children or pregnant women due to problems with bone development and teeth staining
Broad Spectrum - 18TobramycinAminoglycoside
*BACTERICIDAL* (concentration dependent)
Irreversibly binds to the 30S ribosomal subunit, leading to inhibition of protein synthesis and cell membrane damage.
Use reserved for serious Gram- negative infections as several adverse effects e.g. renal failure, respiratory paralysis. - 19Trimethoprim*BACTERIOSTATIC*
Competitively inhibits bacterial folate production essential for bacterial growth. - 20VancomycinGlycopeptide
*BACTERICIDAL*
inhibit bacterial cell wall synthesis by preventing formation of peptidoglycan polymers.
Only effective against Gram-Positive bacteria - 21AminoglycosidesAmikacin
Gentamicin
Streptomycin
**Tobramycin**
Inhibit protein synthesis by irreversibly binding to the 30S ribosomal subunit causing cell membrane damage.
Concentration dependent bactericidal effect. - 22Carbapenems Beta lactamErtapenem
Imipenem
**Meropenem**
Inhibit bacterial wall synthesis by binding to penicillin-binding proteins, usually
bactericidal. - 23Cephalosporins Beta lactamCefaclor
**Cefalexin**
Cefazolin
Ceftriaxone
Interfere with bacterial cell wall peptidoglycan synthesis by binding to penicillin-binding proteins, eventually leading to lysis and cell death.
Bactericidal. - 24GlycopeptidesTeicoplanin
**Vancomycin**
Inhibit bacterial cell wall synthesis by preventing formation of peptidoglycan polymers (prevents cross linking of peptidoglycan). Binds to d-ala-D-ala.
Bactericidal. - 25LincosamidesClindamycin
**Lincomycin**
Inhibit bacterial wall synthesis by binding at the 50S ribosomal subunit.
Bacteriostatic. - 26MacrolidesAzithromycin
Clarithromycin
**Erythromycin**
Roxithromycin
Inhibit bacterial wall synthesis by binding at the 50S ribosomal subunit.
Bacteriostatic. - 27NitroimidazolesMetronidazole
Tinidazole
Metronidazole and tinidazole are metabolised to active metabolites that are thought to interfere with DNA synthesis.
Indicated for Gram-positive and Gram-negative anaerobic bacterial infections. - 28Penicillins Beta lactamsInterfere with bacterial cell wall peptidoglycan synthesis by binding to penicillin-binding proteins, eventually leading to lysis and cell death. Bactericidal.
B-lactam antibiotics such as penicillin inhibit the cross linking reaction between the peptide chains of individual murein building blocks. Penicillin resembles the structure of the two end alanine residues so the penicillin binding protein binds to penicillin instead of the peptide = no cross-linking - 29QuinolonesCiprofloxacin
Moxifloxacin
Norfloxacin
Ofloxacin
Bactericidal; inhibit bacterial DNA synthesis by blocking DNA gyrase and topoisomerase IV. - 30RifamycinsRifabutin
Rifampicin
Rifaximin
Inhibit bacterial RNA polymerase; rifampicin and rifabutin are bactericidal against rapidly dividing M. tuberculosis and active against those which are semi-dormant (intracellular organisms). Rifaximin has a local effect on E. coli that cause traveller’s diarrhoea and on GI flora that produce toxins that cause encephalopathy. - 31SulphonamidesSulphamethoxazole
Competitively inhibiting enzymatic reactions involving para-aminobenzoic acid (PABA). PABA is needed in enzymatic reactions that produce folic acid, which acts as a coenzyme in the synthesis of purines and pyrimidines. Mammals do not synthesize their own folic acid so are unaffected by PABA inhibitors, which selectively kill bacteria. Bactericidal. - 32TetracyclinesDoxycycline
Tetracycline
Inhibits bacterial protein synthesis by binding to the 30S subunit of the ribosome, bacteriostatic.
Only used for specialised applications due to widespread resistance. Cannot be used in young children or pregnant women due to problems with bone development and teeth staining, - 33bacterial cell wall synthesisThe cell wall is unique to bacteria, and it is a target of antibiotics such as beta-lactams.
Peptidoglycan sequence varies from one bacteria to another. The peptide chains can be directly cross linked to one another.
Gap between cell membrane and wall is periplasmic space (Gram-negative). Gram-positive has only
Peptidoglycan is a polymer, made of alternating NAG-NAM, cross inked by chaines of amino acids.
Cell wall of bacteria holds it together, preventing bursting.
Synthesis of peptidoglycan and wall occurs in stages.
⎝ Addition of 5 amino acids to NAM
⎝ NAG is added to NAM, forming precursor of peptidoglyan, transported across membrane to cell wall aceptor in periplasm. Once here, precursors bind to acceptors and crosslink,
⎝ Major enzymes involved in linking are transpeptidiase and d-adenylcarboxypeptidase
⎝ (aka penicillin binding proteins, as they bind to penicillins and cephalosporins.)
⎝ Layers of peptioglycan formed, crosslinked to form cell wall
⎝ Gram-positive have more layers than gram-negative, hence, thicker cell wall. - 34Beta lactamsthe beta lactam ring is what binds to the penicillin binding protein. It inhibits action of the transpeptidation enzymes that cross link the peptidoglycans (the transpeptidase and d-adenylcarboxypeptidase). This prevents bacterial cell wall synthesis. Damages cell wall. Without normal rigid cell wall, osmotic pressure leads to bursting.
Inhibition of cell wall synthesis -> autolysins released by complex of beta ring and enzyme. Bactericidal.
The final bactericidal event is the inactivation of an inhibitor of autolytic enzymes in the cell wall, leading to lysis of the bacterium. Some organisms, referred to as ‘tolerant’, have defective autolytic enzymes in which case lysis does not occur in response to the drug.
B-lactam inhibit the cross linking reaction between the peptide chains of individual murein building blocks. Penicillin resembles the structure of the two end alanine residues so the penicillin binding protein binds to penicillin instead of the peptide = no cross-linking - 35Protein synthesis Inhibitorsthe process is the same in prokaryotes and eukaryotes, but the sizes of their ribosomes differ, so antibiotics target bacterial protein synthesis selectively
Protein synthesis inhibitors work by interacting with the ribosomal subunits and may affect protein synthesis at any one of these stages.
Binding to 50S subunit inhibits formation of the peptide bond
Binding to 30S changes the shape, causing code on mRNA to be read incorrectly or may interfere with the attachment of tRNA to mRNA ribosome complex. - 36Inhibition of nucleic acid replication and transcription DNA & RNA synthesis inhibitorsThe structure of DNA topoisomerases differ between eukaryotes and procaryotes, therefore a reasonable aount of selectdivity for DNA synthesis inhibition. RNA synthesis inhibitors; the structure of RNA polymerase is different between bacteria and humans, allowing for a degree of selectivity
⎝ Gene expression and cell division also require nucleic acid synthesis, interference with which is an important mechanism of action of many chemotherapeutic drugs. It is possible to interfere with nucleic acid synthesis in five different ways:
by inhibiting the synthesis of the nucleotides
by altering the base-pairing properties of the DNA template by inhibiting either DNA or RNA polymerase by inhibiting DNA gyrase, which uncoils supercoiled DNA to allow transcription by a direct effect on DNA itself. Some anticancer drugs, but no antimicrobial drugs work in this way. - 37Inhibition of either DNA or RNA polymeraseSpecific inhibitors of bacterial RNA polymerase that act by binding to this enzyme in prokaryotic but not in eukaryotic cells include rifamycin and rifampicin, which are particularly useful for treating tuberculosis Aciclovir (an analogue of guanine) is phosphorylated in cells infected with herpes virus, the initial phosphorylation being by a virus-specific kinase to give the aciclovir trisphosphate, which has an inhibitory action on the DNA polymerase of the herpes virus
- 38Injury to Plasma MembraneDaptomycin
there are similarities between the plasma membrane of humans and bacteria, so small differences have to be carefully exploited in order to avoid toxicity
cyclic lipopeptide inserts into Gram-positive bacterial cytoplasmic membranes in the presence of calcium.
This causes depolarisation, leading to potassium efflux, consequently impairing potassium dependent synthesis of DNA, RNA and protein.
This leads to cell death - 39Inhibitors of folate metabolismfolate metabolism pathway delivers precursors for DNA, RNA and amino acid synthesis. The first step in the pathway only occurs in bacteria, therefore it is a unique target.
Competitively inhibiting enzymatic reactions involving para-aminobenzoic acid (PABA). PABA is needed in enzymatic reactions that produce folic acid, which acts as a coenzyme in the synthesis of purines and pyrimidines. Mammals do not synthesize their own folic acid so are unaffected by PABA inhibitors, which selectively kill bacteria. Bactericidal
Sulphonamides
trimethoprim blocks DHFR blocking purine synthesis
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- pharmacology (pharmacology 4) FlashCards sobre antibiotics drug list Pharm 4, criado por Amelia Claire em 29-10-2017.
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- Amelia Claire
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