Antimicrobials by names Flashcards
1
Q
Aminoglycosides (7)
A
- Prevents translation of tRNA on 30s ribosomes = protein synthesis inhibition
- gram -ve aerobes
- Tx Nephro + oto
- Tx horse clostridum overgrowth
- adverse reaction with other drugs and ana
- often used with B-lactum
- ending in mycin
2
Q
Amphenicols
A
Bacteriostatic
3
Q
B-lactams
A
- B-lactams all have a 4-sided B-lactam ring which bind to penicillin binding proteins
- stops cross-linking of bacteria cell wall
- triggers peptidoglycan breakdown
- bactericidal
4
Q
Bacitracin
A
- interferes with transport of peptidoglycan precursors across cytoplasmic membrane
- toxicity limits use to topical applications
- common ingredients in non-prescription first-aid ointments
5
Q
Cephalosporins
A
- hypersensitivity common
6
Q
Chloramphenicol
A
- Binds to ribosome 50s which inhibits proteins interpeptide bonds
- Tx = aplastic anemia
- metabolised by the liver
- effective againt gram + and -
- effective in wide range (spirochetes and rickettsia)
- Good penetration of blood brain barrier and eyes
- often used as a last resort
7
Q
fluoroquinolones
A
- Inhibiting bacterial DNA synthesis (Topoisomerase DNA gyrase, = not allowing supercoiling) = bactericide
- Tx inhibiting cartilage growth in young animals
- Tx cat retinopathy
- Against wide range aerobic gram +ive and -ive (not anaerobes)
- well tolerated in birds, reptiles and pocket pets (guinea pigs)
- not registered in food production
- ends in ‘floxacin’
- Note = new one called pradofloxacin which does spectrum gram + an - and Anaerobes
8
Q
Imidazoles
A
- Bactericidal
- inhibiting of nuclei acid synthesis
9
Q
Lincosamides
A
- Bacteriostatic
10
Q
Macrolides
A
- inhibits protein synthesis by inhibiting 50s ribosome
- bactericidal in high doses
- bacteriostatic in lower doses
11
Q
lincomycin
A
- inhibits protein synthesis by inhibiting 50s ribosome
- bactericidal in high doses
- bacteriostatic in lower doses
- eg clindamycin
12
Q
Penicillin
A
- hypersensitivity common
13
Q
Polymixins
A
- bind to phospholipids of gram -ve disrupting membrane (affects eukaryotes too, so only used topically) = inhibition of membrane fx
- bactericide
- often used in together with bacitracin
14
Q
Rifamycins
A
- inhibits RNA polymerase
15
Q
Sulphonamides
A
drug hypersensitivity in dobermans = delayed sulphonamide metabolism
16
Q
Tetracycline
A
- binds to 30s ribosomal subunit, blocking tRNA attachment
- affects gram +ve aerobes and gram -
- Bacteriostat
- Broad spectrum antibiotic
- Tx = impact bone growth
- Tx = teeth staining in young animals
- Tx = tissue necrosis at injection sites
- Tx = hepatic microsomal induction/inhibition
- Tx = adverse reactions with a aesthetics
- Tx = oesophageal strictures (doxycycline)
- Eg all end in cycline
newer eg doxycycline have longer half-life
used for intracellular bacteria (Chlamydia, mycoplasma, rickettsia)
17
Q
Tripmethoprim/sulphonamides
A
- Bactericidal in combinations
- bacteriostatic when given alone
- inhibitions of synthesis of essential metabolites
- Sulphonamides = competitive inhibition of enzymes
- Trimethoprim = blocks enzymes in folic acid synthesis (required for growth)
- Increased resistance so not used often by itself, for UTI
- Bacteriostats
- Toxicity = kerroconjuctivits sica with prolonged use
- Tx idiosyncratic hepatotoxicity in dogs
- Tx athropathies, cutaneous reactions and haemolytic anaemia
- Hypersensitivity reaction common
18
Q
Vancomycin
A
glycoproteins
- binds to the D-alanyl-Dalanine end of the peptidoglycan pentapeptide chain rather than to the PBP enzyme
- only effective against gram positive, as too large to enter gram negative membrane to get to cell wall
- “last line: against antibiotic resistant “s.aureus”
19
Q
Nitroimidazoles
A
- binds to and fragments DNA
- Particularly effective in anaerobes
