Antibacterial agents Flashcards
(176 cards)
1
Q
Cell wall synthesis inhibitors
A
- Penicillins
- Cephalosporins
2
Q
What are the five groups of penicillins?
A
- Natural penicillins (Penicillin G**)
- Aminopenicillins**
- Anti-staph penicillins
- Anti-pseudomonal penicillins
- Beta-lactamase inhibitor combinations (Amoxicillin clavulanate*)
3
Q
How many generations of cephalosporins?
A
- 3
4
Q
Which penicillins are used the most in vet med?
A
- Penicillin G*
- Aminopenicillins* (Amoxicillin, ampicillin, others)
- Amoxicillin clavulanate**
5
Q
Cephalosporins used frequently in vet med?
A
- Cephalothin, cephalexin, cefazolin*
- Ceftiofur, cefpodoxime, cefovecin, ceftriaxone
6
Q
Other beta lactams that are used in human med
A
- Imipenem
7
Q
Glycopeptides used in human med
A
- Vancomycin
8
Q
Protein synthesis inhibitors
A
- Tetracyclines
- Aminoglycosides
- Amphenicols
- Macrolides
- Lincosamides
9
Q
Which are the natural penicillins?
A
Penicillin V and Penicillin G
10
Q
What are the aminopenicillins?
A
- Amoxicillin, ampicillin, others
11
Q
What are the anti-staph penicillins?
A
- Methicillin, cloxacillin, dicloxacillin, oxacillin
12
Q
What are the anti-pseudomonal penicillins?
A
- Ticarcillin, piperacillin, carbenicillin
13
Q
What are the beta lactamase inhibitor combinations?
A
- Amoxicillin clavulanate; others
14
Q
What are the 1st gen cephalosporins?
A
- Cefadroxil, cephalothin, cephalexin, cefazolin
15
Q
What are the 2nd gen cephalosporins?
A
- Cefaclor, cefoxitin, others
16
Q
What are the 3rd gen cephalosporins?
A
- Ceftiofur, cefpodoxime, cefovecin, ceftriaxone
17
Q
What are the tetracycline family drugs?
A
- Tetracycline, oxytetracycline, doxycycline
18
Q
Aminoglycoside family
A
- Gentamicin, Amikacin, tobramycin (ophthalmic), neomycin (topical)
19
Q
Amphenicols family
A
- Chloramphenicol, florfenicol, thiamphenicol
20
Q
Macrolides family
A
- Erythromycin, tilmicosin, azithromycin, tylosin, tulathromycin
21
Q
Lincosamides family
A
- Lincomycin, clindamycin
22
Q
Antimetabolite drugs
A
- Sulfonamides
- Folate reduction inhibitors
- Potentiated sulfonamides
23
Q
Sulfonamide drugs
A
- Sulfadiazine, sulfasalazine
24
Q
Folate reduction inhibitors
A
- Trimethoprim, ormetoprim, pyrimethamine
25
Potentiated sulfonamides
- Trimethoprim-sulfa; ormetoprim-sulfdaimethoxine
26
Nucleic acid synthesis inhibitors
1. Fluoroquinolones
2. Rifampin
3. Metronidazole
27
Fluoroquinolone examples
- Enrofloxacin
- Orbifloxacin
- Difloxacin
- Marbofloxaacin
- Danofloxacin
- Ciprofloxacin
28
MOA of Beta-lactams**
- All are considered bactericidal**
- Targets penicillin binding protein and bind the bacterial transpeptidase enzymes (AKA penicillin binding proteins) that disrupt the wall
29
Vancomycin MOA
- Binds precursors of peptidoglycans interfering with bacterial cell wall synthesis
30
What are the two important mechanisms of resistance to penicillins?***
1. Enzymatic destruction by Beta-lactamases produced by bacteria*** (cephalosporin lactam ring is more resistant)
2. Altered target** (altered penicillin binding protein)
31
Mechanism of resistance of vancomycin
- Altered target (peptide)
32
Penicillins susceptibility for Gram +/Gram - and Aerboci/Anaerobic*******
- USE THE QUADRANT CHART THAT HE HAS TO REMEMBER THIS
33
Natural penicillins and aminopenicillins efficacy against Pseudomonas and Staphylococcus***
- NOT EFFECTIVE AGAINST PSEUDOMONAS OR STAPHYLOCOCCUS
34
Anti-pseudomonal drugs susceptibility to beta lactamase
- Susceptible to beta lactamase
35
Penicillins for aerobic and Gram +
- Natural
- Aminopenicillins
- Antipseudomonal
36
Penicillins for aerobic and gram -
- Natural (limited)
- Aminopenicillins (better than Natural)
- Antipseudomonal
37
Penicillins for anaerobic and gram +
- natural P
- Aminopenicillins (slightly less than nat Pen)
- Anti-pseudomonal
38
Penicillins for anaerobic and gram -
- Natural P (limited)
- Aminopenicillins (slightly less than Nat P)
- Antipseudomonal
39
***Cephalosporin activity
- SEE THE CHAT****
40
Other beta-lactam spectrum fo activity***
- SEE THE CHART
41
Imipenem-cilastin spectrum of activity***
- Bactericidal
- Cilastin merely inhibits rapid metabolism of imipenem in the renal tubules, prolonging its duration in the body
- Both drugs are often reserved for very resistant organisms in human patients, so veterinary use should be limited**
42
Toxicity of beta lactams**
- In general very safe
- The most common adverse reaction is hypersensitivity (allergy) which can be life-threatening***
- Some of the cephalosporins have been associated with renal failure (very rare)**
43
Which cephalosporins are useful against anaerobic bacteria?
- Cefoxitin
- Cefotetan (2nd gen)
- The rest are weak
- Useful for gram pos and gram neg
44
Spectrum for Imipenem
- Gram +/Gram - aerobic and anaerobic
45
Spectrum of vancomycin
- Aerobic gram + and Gram -
46
Beta lactam effect on GIT
- Any antibiotic can potentially alter normal flora of the GIT resulting in diarrhea, and any drug can potentially irritate the stomach and small intestine, causing vomiting or inappetence
47
Procaine penicillin G racehorses
- Can cause a positive procaine test reaction (consideration in performance animals, e.g. racehorses) for up to 2 weeks after injection
48
Vancomycin route
- IV
49
Vancomycin adverse reactions
- Rapid IV administration causes a hypersensitivity type reaction (histamine release)***
- It has also occasionally been associated with renal toxicity, ototoxicity, and reversible thrombocytopenia and neutropenia***
50
Vancomycin use in food animals
- Prohibited
51
Which beta lactams can be given PO?
- Aminopenicillins**
| - Beta lactamase inhibitor combinations***
52
How often do Na+/K+ salts of penicillin ned to be given?
- QID (disadvantage)
53
Potassium penicillin use
- Commonly used in foals needing intensive care**
| - IV
54
PPG use
- Commonly used in horses and cattle
| - Often given IM (large amounts)
55
Use of benzathine penicillin G
- Shipping fever complex (Strep, Staph aureus, Arcanobacterium pyogenes)
- Blackleg (Clostridium chauvoei)
56
Use of Aminopenicillins
- Horses (IV)
- Cattle (amoxicillin intramammary)
- Dogs and cats
57
Anti-staph penicillins use
- Mastitis in dairy cattle
58
Use of anti-pseudomonal penicillins
- Ticarcillin IV
- Treat serious Gram negative infections in dogs
- Intrauterine in mares
59
Beta lactamase inhibitor combo uses
- Not used in large animals (no label for food animal; poor oral absorption horses)
60
Oral cephalosporins
- Cefadroxil and cephalexin (1st gen)
| - Cefpodoxime (3rd gen)
61
Cefadroxil and cephalexin oral bioavailability in horses
- Very low**
| - Otherwise most commonly used 1st generation cephalosporin
62
Cefazolin indication**
- Used in dogs, cats, and horses
| - Penetrate bone*** (prophylactically for orthopedic surgeries)
63
Cephapirin clinical use
- Formulation for dairy cattle
64
Indication for cefoxitin and cefotetan
- Used for abdominal surgical prophylaxis (dogs and cats)*** because of activity against Gram negative and some anaerobic organisms
65
Clinical use for ceftiofur
- Treating UTI in dogs and cats (SQ) - not used a lot
| - Treating respiratory infections in horses, cattle, and pigs**
66
Cefovecin or Convenia clinical use
- Recently approved as a one-time injectable drug for treating skin infections in dogs and cats**
67
Cefpodoxime clinical use
- Labeled for the treatment of skin infections once a day in dogs.***
- It is not labeled for use in other species.
68
Carbapenems clinical use***
- None are labeled for use in veterinary medicine, but are occasionally used in dogs, cats, and foals for severe, resistant infections***
69
Clinical use of vancomycin
- Not labeled for use in vet med
- Illegal to use in food animals
- Occasionally used for resistant Staphylococcal (particularly MRSA) and/or Enterococcus infections in dogs, cats, and horses
70
Protein synthesis inhibitors mechanism of action
- See image
71
Tetracycline MOA
- Targets 30s ribosomal subunit
| - Bacteriostatic**
72
Amphenicols/Macrolides/Lincosamides MOA
- Targets 50S
| - Bacteriostatic
73
Aminoglycosides MOA
- Targets 30S ribosomal subunit to cause production of a misfolded protein
- Dictates that membrane function will change
- Bacteriocidal***
74
Resistance to Tetracycline MOA
- Efflux pump that transports the drug out of the bacterial cell; therefore, the drug fails to reach its target. Plasma encoded.
resistance to one tetracycline produces cross resistance to another**
75
Resistance to Lincosamides/macrolides/amphenicols MOA
- Inactivation/degradation by bacterial enzymes
76
Resistance to Aminoglycosides MOA
- Inactivation/degradation by bacterial enzymes
| - Failure to reach the target because of decreased porin size occurs in some gram negative organisms
77
Spectrum of tetracycline
- Aerobics and anaerobics
| - Gram pos and gram neg
78
Spectrum of Aminoglycosides
- Aerobics
| - Gram pos and Gram neg
79
Spectrum of Clindamycin**
- Gram + aerobes and anaerobes (except Clostridium difficile)
80
Spectrum of macrolides
- Original only Gram + aerobes
| - Newer have broad spectrum activity against Gram +/Gram - Aerobes and Anaerobes
81
Inherent resistance to tetracyclines and amphenicols
- Staph, Pseudomonas, and E. coli should be considered resistant to tetracyclines until proven otherwise
82
Inherent activity of tetracyclines and amphenicols
- Rickettsiaceae and Anaplasmataceae, and Chlamydia
83
Toxicity of tetracyclines
- GI side effects including anorexia, vomiting, and diarrhea***
- Rapid IV administration in many species has resulted in collapse (possibly due to calcium chelation?). In horses, IV administration of doxycycline can be fatal***
- Permanent brown discoloration of teeth if administered during tooth development.
- Other side effects include drug-induced fever, renal toxicity, hepatic toxicity*** (seeing more doxycycline-induced recently), and allergic reactions
84
Tetracyclines in horses
- Assume that they may develop diarrhea just inherently
In horses, IV administration of doxycycline can be fatal***
- Including anorexia, vomiting, and diarrhea
85
Doxycycline in cats
- Particularly prone to esophageal lesions (fibrosis and stricture) caused by tetracyclines**
- Any dose should be followed by water to prevent lodging of a tablet or capsule in the esophagus
- Doxycycline hyclate (rather than doxycycline monohydrate) is associated with more esophageal damage
86
Aminoglycosides toxicity
- Nephrotoxicity***, ototoxicity, and neuromuscular blockade
87
Nephrotoxicity of aminoglycosides
- Relatively common - 25% of human patients receiving aminoglycosides for 3 days or more experience nephrotoxicity! Aminoglycoside concentrations are 50 times in renal tissue than in plasma
88
How to mitigate nephrotoxicity of aminoglycosides
- Use the least toxic aminoglycoside (amikacin is thought to be less likely than gentamicin to cause nephrotoxicity)
- Do not use in patients that are hypovolemic
- Avoid concurrent use of other nephrotoxic drugs (furosemide, NSAIDs)
89
Otoxocitiy of aminoglycosides
- Ototoxicity is irreversible
- Can include both auditory and/or vestibular toxicity
- Ototoxicity can occur with topical, particularly otic, or systemic administration
- Ensure tympanic membrane is intact
- Otic administration of aminoglycosidess should be avoided in patients with a ruptured tympanic membrane
- Auditory toxicity is more common in dogs than in cats while vestibular toxicity is more common in cats than dogs
90
Neuromuscular blockade and aminoglycosides
- Reversible
- Risk is greatest at high doses (rapid IV administration) or when combined with other agents acting at the neuromuscular junction (anesthetics, skeletal muscle relaxants)
91
Chloramphenicol use in small animals
- Frequently avoided due to the potentiaal for a human toxicity (irreversible aplastic anemia)
- Can cause a reversible bone marrow suppression in dogs and cats
92
Chloramphenicol drug interactions
- Inhibits CYP 450 enzymes
| - many drug interactions
93
Advantages of florphenicol over chloramphenicol
- Developed for use in food animals
- It is not associated with aplastic anemia in people so it is not prohibited in food animals
- Does not inhibit CYP 450 enzymes. I
94
Florphenicol use in horses
- Can cause severe diarrhea in horses
95
Erythromycin adverse effects
- Frequently causes GI upset and vomiting
- Thought to result from its interaction with the motilin receptor which stimulates GI motility (sometimes used as prokinetic). Newer macrolides do not have this effect.
96
Macrolides in horses
- Frequently used in foals (particularly for Rhodococcus equi pneumonia)
- Use in adult horses is frequently associated with severe colitis; therefore, use of macrolides should be avoided in adults
- Hyperthermia in foals***
97
Tilmicosin adverse effects*****
- Can cause severe cardiovascular toxicity at high doses in cattle, and even in low doses can e fatal in swine, horses, goats, and people
- Other macrolides do not share this adverse effect
98
Tilmicosin antidote
- No antidote
99
Lincosamides in horses
- Generally not used because they can cause an overgrowth of Clostridium difficile resulting in severe pseudomembranous colitis
100
Lincosamides drug interactions
- Clindamycin especially in small animals
- Often used in combination therapy
- Avoid using lincosamides concurrently with other drugs that bind to the 50s ribosome (amphenicols and macrolides)
- Can use with beta lactams
101
What is the most commonly used tetracycline in large animal vet med?
- Oxytetracycline
- Used for treating bovine respiratory diseases, mastitis, and anaplasmosis
- Intrauterine infusion of oxytetracycline is used for cows with retained fetal membranes (extralabel)
- In horses, oxytetracycline has been used to treat Neorickettsia risticii (Potomac horse fever)
102
Most commonly use tetracycline in small animal vet med?
- Doxycycline
103
Doxycycline route
- PO
| - Injectable
104
Doxycycline distribution**
- Lipophilic and thus penetrates tissues well and is considered the drug of choice for treating intracellular pathogens such as Ehrlichia, Rickettsia, and Mycoplasma including M. haemofelis (formerly called haemobartonella felis)
105
Doxycycline use for UTI**
- Does not achieve high concentrations in urine
| - Not a good choice for UTIs
106
What are most commonly used aminoglycosides in vet med?
- Gentamicin (LA)
- Amikacin (SA)
- Neomycin
107
What are differences of gentamicin and amikacin?
- Amikacin is less susceptible to bacterial inactivation than gentamicin
- Amikacin is potentially less likely to produce nephrotoxicity
- Amikacin is more expensive than gentamicin
108
Gentamicin use
- Frequently used in horses systemically as part of PPG
| - Gentamicin is also used for regional limb perfusion to treat lower limb bone and joint infections
109
Amikacin species use
- Foals, dogs, and cats
| - Amikacin also used as intrauterine infusion for horses
110
Amphenicols distribution
- Lipid soluble**
| - Achieve high concentrations within cells and can gain access to tissues such as CNS and prostate
111
Chloramphenicol clinical use**
- In small animals used primarily for CNS infections, some rickettsiae, and mycoplasma
- Chloramphenicol is sometimes used in horses (has reasonable oral bioavailability and does not cause serious adverse effects on the GI flora), but is ILLEGAL for use in food animals
- Not used much in small animals
112
Florphenicol clinical use
- Approved for use as an injectable (IM or SQ) for treating bovine respiratory disease and bovine interdigital phlegmon (foot rot)
113
Macrolides distribution
- Lipid soluble (especially azithromycin) and are therefore useful against susceptible intracellular bacteria
- Because of its long tissue half-life in the respiratory tract, it has unusual dosing recommendations (once every 3 days; OR once a day for 3 days then stop)
114
Which macrolides are most often used for small animals and horses?
- Erythromycin, azithromycin, and clarithromycin
115
Clinical use of macrolides in small animals and horses
- In horses, clarithromycin and azithromycin are effective for treating Rhodococcus equi infections (one paper suggested that erythromycin plus rifampin was best)
- They are used in dogs and cats to treat a variety of respiratory infecitons (not used as much)
116
Newer macrolides
- Gamithromycin
- Tulathromycin
- Tilmicosin
117
Use of newer macrolides
- Approved for use as an injectable (IM or SQ) for treating bovine respiratory disease and bovine interdigital phlegmon (foot rot)
- Tulathromycin quite common
118
What is the most commonly used lincosamide?
- Clindamycin***
119
***What is clindamycin most commonly used for in SA?
- Wounds, abscesses, periodontal disease, and osteomyelitis
120
Drugs that are analogs of PABA
- Sulfadimetoxine
- Sulfadiazine
- Sulfametoxazole
121
Folate reduction inhibitors
- Ormetoprim
| - Trimetoprim
122
Combinations of analogs of PAbA and folate reduction inhibitors
- Sulfadimetoxine with ormetoprim
- Sulfadiazine with trimethoprime
- Sulfametoxazole with trimethoprim
123
What enzyme do sulfas inhibit?
- Dihydropteroate synthase
124
What enzyme does trimethoprim inhibit?
- Dihydrofolate reductase
125
MOA of antimetabolites
- See chart
- Both inhibit tetrayhydrofolic acid (active form of folic acid) through different mechanisms
- This is used for protein synthesis by bacteria
- Bacteriostatic used alone
126
Combination of sulfonamide with a folate reduction inhibitor
- Synergistic and bacteriocidal
127
MOA of resistance for antimetabolites
- There are numerous mechanisms of resistance to the antimetabolites; the most important plasmid-mediated form of resistance is impaired penetration
- This resistance has limited the clinical utility of these drugs in many clinical situations
128
Spectrum of potentiated sulfonamides
- Aerobes, Gram + and Gram -
129
Which bacteria should you not use potentiated sulfonamides for?
- NOT good choices for Staph, Enterococcus, E. coli, Proteus, Klebsiella, Pseudomonas
- Many anaerobes
- If you don't do a susceptibility test, you wouldn't know
130
Adverse effects of sulfonamides
- Most important adverse effect is hypersensitivity reaction, which occurs in people too
- Immune-mediated diseases ranging from mild to severe can affect skin, liver, kidney, hematopoietic system, and eyes
- Keratoconjunctivitis sicca (KCS; decreased tear production by the lacrimal glands), and it is recommended that the patient be monitored during treatment with Schirmer tear tests*** (monitor a baseline, then monitor over time)
- If a decrease in tear production is noted, the drug should be discontinued, with normal tear production expected to resume
- Check tear production at same time every day
131
Sulfonamides and nephrotoxicity
- Rarely, nephrotoxicity** associated with sulfonamide crystalluria has been reported in DOGS
- Sulfonamides are metabolized by acetylation - because dogs lack this metabolic pathway, they are more likely to develop adverse effects than other species
- Be careful in animals with kidney disease or when using other drugs that can cause kidney damage
132
Clinical use of sulfonamides and potentiated sulfonamides
- Available in a variety of forms (oral, injectable, feed additives) with indications including treatment of intestinal...
- Infections in CNS, joints (synovial fluid) coccidiosis
- Bacterial enteritis
- Bacterial pneumonia
- Skin and soft tissue infections in dogs and cats
- Cystitis and prostatitis in dogs
133
Clinical use of Sulfadimethoxine (Albon)
- Labeled for use in many species
134
Clinical use of Sulfadimethoxine + ormetoprim (Primor)
- Labeled for use in dogs
135
Clinical use of sulfadiazine + trimethoprim (Tribrissen)
- labeled for use in horses; availability for dogs and cats has declined
136
Clinical use of sulfamethoxazole + trimethoprim
- Most common human formulation but used off-label in dogs, cats, and horses
137
Sulfonamides use in food animals
- Sulfonamides have caused the most tissue residue violations in the US with the greatest problems coming from pork, veal, and poultry
138
Nucleic acid synthesis inhibitors
1. Fluoroquinolones (Enrofloxacin, orbifloxacin, difloxacin, marbofloxacin, danofloxacin ciprofloxacin)
2. Rifampin
3. Metronidazole
139
MOA of Fluoroquinolones
- Inhibit the bacterial DNA gyrase (topoisomerase II) enzyme which is necessary for transcription, translation, and bacterial replication.
- Bacteriocidal
140
Folic acid inhibitor toxicity
Not toxic
141
MOA of Rifampin
- Bactericidal at high concentrations**
| - Rifampin inhibits DNA-dependent RNA polymerase interfering with RNA synthesis
142
MOA of Metronidazole
- Bactericidal
- By an undefined mechanism, metronidazole impairs microbial RNA and DNA synthesis
- Induces free radical production in the bacteria
143
MOA of resistance for fluoroquinolones
- Alteration of the target (Topoisomerase II)
- Decreased porin size (how it gets into the cell) by gram negative bacteria, resulting in failure of the drug to reach its target
144
Rifampin MOA of resistance
- Alteration of drug target
| - If used as a sole agent, resistance often develops, rapidly limiting the usefulness of this drug***
145
Metronidazole MOA of resistance
- Unknown, but resistance exists
146
Fluoroquinolones spectrum
- Fluoroquinolones aerobic Gram + and Gram -
| - Ineffective against anaerobes***
147
Metronidazole spectrum
- Anaerobic gram + and Gram -
148
Rifampin spectrum
- Gram + aerobic
149
Spectrum of Pradofloxacin
- Gram + Anaerobic
- Next generation fluoroquinolone that is FDA approved for cats
- Has greater gram positive and anaerobic activity while maintaining gram negative activity
- For cats, the only specific antibiotic you have for anaerobic gram positive bacteria, as metronidazole is toxic in cats
150
Toxicity of Fluoroquinolones in young animals
- Irreversible cartilage damage in growing animals (documented in dogs and foals); therefore, fluoroquinolones should not be used in growing animals
151
Toxicity of Fluoroquinolones in cats
- Retinopathy in cats that results in irreversible blindness
- This tends to be related to higher doses, or use in cats with compromised renal function
- Polymorphism in the transporter in the eyes
- Keep the cat inside to avoid this
152
Toxicity of Fluoroquinolones in general
- at high plasma concentrations such as those achieved after IV injection or extremely high oral doses, seizures can be induced by fluoroquinolones**
153
Rifampin toxicity
- Liver toxicity
| - Can cause a red-orange discoloration of urine
154
Rifampin drug interactions
- It induces drug metabolizing enzymes so drug interactions are a concern
155
Metronidazole toxicity
- Dose-dependent vestibular toxicity (generally slowly reversible)
- Neurotoxicosis in two cats**
- Genotoxicity of PBMCs (monocytes) appears to resolve within 7 days of discontinuing administration
156
Which fluoroquinolones are FDA approved for dogs and cats or dogs?
- Dogs and cats: Enrofloxacin, marbofloxacin, orbifloxacin
| - Dogs only: Difloxacin
157
Advantage of fluoroquinolones over aminoglycosides
- Lower incidence of side effects than aminoglycosides in general
- Otherwise spectrum of activity is very similar
158
Distribution of Fluoroquinolones
- Lipid soluble and achieve high intracellular concentrations and penetrate tissues including prostate, respiratory tract, and CNS
159
Fluoroquinolones and UTIs
- All of the veterinary labeled drugs except for difloxacin achieve high concentrations in urine and are therefore good choices for resistant urinary tract infections
160
Fluoroquinolones in horses approval
- No FQ approved for use in horses
- Enrofloxacin is most commonly used (orally and by injection)
- Orbifloxacin and marbofloxacin are available too (not used often due to cost)
161
FQ in cattle clinical use
- In cattle, enrofloxacin, and danofloxacin are approved for treating bovine respiratory disease
- Extralabel use of fluoroquinolones in food animals is illegal***
162
FQ in poultry clinical use
- Because of potential for causing spread of resistant Campylobacter, fluoroquinolones that were once approved for use in poultry were pulled from the market
163
FQ Absorption
- Well absorbed after oral administration, although drug interactions do occur
- Divalent (magnesium and calcium) and trivalent (aluminum) cations significantly decrease oral bioavailability and can lead to therapeutic failure (so be careful if your patient is drinking milk)
164
FQ drug interactions
- FQs inhibit cytochrome P450 drug metabolizing enzymes, which can cause an increase in plasma concentrations of some drugs if concurrently administered with fluoroquinolones
- Especially enrofloxacin
165
Rifampin clinical use
- In vet med, rifampin is used mainly in combination with macrolides for treating Rhodococcus equi pneumonia in foals
166
Metronidazole approval
- No FDA approved vet formulations
167
Metronidazole clinical use
- Highly lipid soluble, therefore distributes well to the CNS and into abscesses
- It is used to treat anaerobic infections in dogs and horses primarily
- Too neurotoxic for cats
168
Metronidazole in food animals
- ILLEGAL in food animals and current formulations are inconvenient for dosing cats
169
MRSA infections options
- Chloramphenicol
- Tetracycline (doxycycline, minocycline)
- Aminoglycosides (gentamicin, amikacin)
- Rifampin
- Drugs to consider if a susceptibility test can confirm activity
170
Pseudomonas infection options
- Amikacin and gentamicin
- 2nd or 3rd generation cephalosporins
- Anti-pseudomonal penicillins (ticarcillin, piperacillin, carbenicillin; piperacillin-tazobactam
- Imipenem (IV therapy)
- Fluoroquinolone, combined with beta-lactam
- In many situations aminoglycosides and fluoroquinolones are not effective
- In many times just the 3rd gen cephalosporins and anti-pseudomonal penicillins
171
Nocardia abx
- Potentiated sulfonamides
172
Mycoplasma abx
- Tetracyclines
- Macrolides
- Amphenicols
173
Rickettsiaceae and Anaplasmataceae abx
- Tetracyclines
174
Abx for Gram + anaerobes
- Pradofloxacin (cat)
- Clindamycin
- Metronidazole (no cat)
- Aminopenicillins
- Natural penicillins
- Tetracyclines
- Newer macrolides
175
Abx for Gram - anaerobes
- Pradofloxacin (cat)
- Metronidazole (no cat)
- Aminopenicillins
- Amphenicols
- Newer macrolides
176
Four quadrant antibiotics (pick for empirical treatment)
- Ampicillin with enrofloxacin (avoid in young animals)
- Amoxicillin/clindamycin/metronidazole + fluoroquinolones (dog) - Avoid in young animals
- Amoxicillin/clavulanic (cat)
- Imipenem (not an option for empirical and ambulatory treatment)
- Penicillin and gentamicin or amikacin (not for ambulatory treatment)
- Tetracycline, amphenicols, and newer macrolides (small animals??)
