Term
• Penicillins
e) The mechanism of action. How does it work? |
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Definition
- bind reversibly w/ enzymes outside the bacterial cytoplasmic membrane
- these enzymes (PBPs – penicillin-binding proteins) are involved in cell wall synthesis and cell division; when binding occurs, it increases osmotic pressure, ruptures cell
- some bacteria produce beta-lactamase (penicillinase) which increases the resistance of bacteria by converting penicillin to inactive penicillic acid
- some penicillins more resistant to beta-lactamase hydrolysis and are referred to as beta-lactamase resistant penicillins
- penicillins usually very effective against gram +
- gram – have an outer membrane around the cell wall that limits PBP permeability
- some penicillins have an increased ability to penetrate this outer membrane and may be more effective against gram – bacteria |
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Term
| Penicillins f) Considerations or clinical uses. |
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Definition
| Bacterial infxns resulting from penicillin-susceptible microorganisms |
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Term
| Penicillins - List possible adverse side effects |
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Definition
- allergic rxns
- V
- D
- Enteritis
- Hives/resp distress – epi STAT if resp distress severe |
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Term
| Penicillins - List at least 2 drugs within that drug class (maybe within the textbook or your hospital). |
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Definition
- Amoxicillin – many brands avail
- Ampicillin – Amp-Equine, Amplicillin trihydrate (Polyflex)
- Carbenicillin – Geopen, Pyopen
- Cloxacillin – Cloxapen, Orbenin, Tegopen
- Dicloxacillin – Dynapen
- Penicillin G – many brands avail
- Ticarcillin – Ticar, Ticillin |
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Term
| Cephalosporins - The mechanism of action. How does it work? |
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Definition
- sim to penicillins, interfere w/ cell wall synthesis by binding to the bacterial enzymes (PBPs)
- spectrum of activity is revealed by that drug’s ability to penetrate the bacterial wall and bind w/ proteins w/in the cytoplasmic membrane
- another sim between ceph/pen is the susceptibility of cephalosporins to beta-lactamases (cephalosporinases), which can be produced by certain bacteria
- some cephalosporins are more effective in treating individuals w/ infection caused by bacteria that produce beta-lactamase II |
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Term
| Cephalosporins - Pharmacokinetics |
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Definition
- most admin parenterally because lack ability to be well absorbed by GI tract
- dist to tissues/fluids w/ exception of CNS (some absorbed into cerebrospinal fluid but absorption limited)
- metabolism occurs in liver, elim kidneys by glomerular filtration and tubular secretion into urine (so doses must be modified for pts in renal failure) |
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Term
| Cephalosporins - Considerations or clinical uses. |
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Definition
- cystitis, skin and soft tissue infxns in dogs/cats
- bovine mastitis, shipping fever and other resp infxns in cattle, horses, sheep and swine
- ceftiofur sodium (Naxcel) is approved for use in lactating dairy cows and also day-old chicks/turkey poults for control of early mortality usually assoc w/ E. coli |
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Term
| Cephalosporins - List possible adverse side effects. |
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Definition
- usually safe for use in animals but allergic rxns can occur
- rare bleeding disorders have been reported w/ some
- some have caused seizures, although rare
- V/D |
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Term
| Cephalosporins - List at least 2 drugs within that drug class |
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Definition
- Cefaclor (1st gen) – Ceclor
- Cefadroxil (1st gen) – Cefa-Tabs, Cefa-Drops
- Cefazolin (1st gen) – Ancef, Kezol, many others
- Cefepime (4th gen) – Maxipime
- Cefotetan (2nd gen) – Cefotan
- Cefoxitin (2nd gen) – Mefoxin
- Ceftazidime (3rd gen) – Fortaz, Ceptaz, Tazicef, Tazidime
- Ceftiofur (3rd gen) – Naxcel, Excenel
- Cephalexin (1st gen) – Keflex and generic forms
- Cephalothin (1st gen) – Keflin
- Cephradine (1st gen) – Velosef
- Cefpodoxime (3rd gen) – Simplicef (admin SID) |
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Term
| Aminoglycosides - The mechanism of action. How does it work? |
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Definition
- inhibit protein sysnthesis and impede bacterial cell division (sim to tetracyclines)
- have a broad spectrum of activity but should be used only in cases of gram – infxn
- streptococcal bacteria species don’t show much sensitivity to aminoglycosides
- most often effective against anaerobic bacteria |
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Term
| Aminoglycosides - Pharmacokinetics |
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Definition
- admin parenterally except neomycin (orally)
- absorbed into bloodstream then extracellular fluid
- do not reach therapeutic levels in bile, cerebrospinal fluid, resp secretions, protatic/ocular fluid, fetal tissue
- elim by glomerular filtration into urine
- tend to accumulate at high concentrations in renal cortical tissue so adequate renal fxn important – recc monitor for nephrotoxicity by getting pre/intra/post tx serum creatinine levels – sig change could indicate need for termination of tx
- also concentrates in inner ear, in which levels do not diminish until tx completed – ototoxicity may be vestibular or auditory |
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Term
| Aminoglycosides - Considerations or clinical uses. |
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Definition
Infxns caused by aminoglycoside-susceptible microorganisms
- pneumonia
- enteritis
- UTI
- Bacterial enteritis
- Conjunctivitis
- Skin/soft tissue infxns |
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Term
| Aminoglycosides - List possible adverse side effects. |
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Definition
- D - may disrupt intestinal bacterial flora)
- Neuromuscular blockage (when used w/ anesthetic neuromuscular blocking drugs) Aminoglycoside blood levels can be determined b4 using these agents
- Contraindicated w/ renal insufficiency |
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Term
| Aminoglycosides - List at least 2 drugs within that drug class |
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Definition
- Amikacin – Amiglyde-V
- Gentamicin – Gentocin
- Kanamycin – Kantrim
- Neomycin - Biosol |
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Term
| Tetracyclines - The mechanism of action. How does it work? |
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Definition
- inhibit protein synthesis, thereby impeding cell division
- offer a broad spectrum of activity against gram + and gram – bacteria
- bacteriostatic, although at high dose concentrations they may become bactericidal |
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Term
| Tetracyclines - Considerations or clinical uses. |
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Definition
- resp tract infxn, bacterial enteritis, and urinary tract infxns caused by tetracycline-susceptible microorganisms
- rickettsial dzs (eg, borreliosis {Lyme dz}, Rocky Mtn spotted spotted tick fever) |
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Term
| Tetracyclines - List possible adverse side effects |
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Definition
- may cause renal problems at high doses
- can affect formation of bones/teeth (staining of teeth) in young animals
- never horses IV
- may cause drug fever in cats
- some hepatotoxicity may occur at increased doses, esp in susceptible individuals |
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Term
| Tetracyclines - List at least 2 drugs within that drug class |
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Definition
- Chlortetracycline – Anaplasmosis block, Aureomycin soluble poweder, Aureomycin tablets, Aureomycin soluble calf oblets, calf scour bolus, Fermycin
- Doxycycline
- Minocycline
- Oxytetracycline – Terramycin, many others
- Tetracycline |
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Term
| Chloramphenicol - The mechanism of action. How does it work? |
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Definition
- Broad spectrum abx that acts against gram -/ gram + bacteria
- Readily absorbed into tissue/body fluids
- Metabolized by liver, excreted through kidneys into urine |
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Term
| Chloramphenicol - Considerations or clinical uses |
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Definition
| - bacterial respiratory tract infnx, UTI, enteris, or bacterial conjunctivitis caused chloramphenicol-susceptible organisms |
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Term
| Chloramphenicol - List possible adverse side effects. |
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Definition
- blood dyscrasias in cats after prolonged tx
- not recommended for dogs maintained for breeding
- very stable, not for use in food-producing animals because of residual amts of drug can be left in meat, milk, or eggs
- not admin simultaneously w/ penicillin, streptomycin, or the cephalosporins |
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Term
| Chloramphenicol - List at least 2 drugs within that drug class |
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Definition
- Chloramphenicol 1% Opthalmic Ointment
- Duricol Chloramphenicol Capsules
- Chloromycetin |
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