Antifungals And Antimicrobials Flashcards
What are the main gram positive aerobic cocci?
Staphylococcus and streptococcus,
What are the main gram positive aerobic rods?
Bacillus, listeria, Norcardia, corynebacterium
What’s are the clinically relevant gram pos anaerobic cocci?
Peptostreoptococcus (oral bacteria)
What’s the clinically relevant gram positive anaerobic rod bacteria?
Clostridium, actinomyces
what are the clinically relevant aerobic gram negative cocci?
None in companion animal
What’s are the clinically relevant gram neg aerobic rod bacteria?
Enterobacteriaceace ( E. coli, salmonella, proteus, klebsiella) psuedomonas
What are the clinically relevant gram negative anaerobic coccci?
None
What are the clinically relevant gram neg anaerobic rods?
Bactericides, fusibacterium, (periodontal bacteria) pasturella
What drug classes are in the beta lactams?
Carbopanems,monobactams, penicillins, cephalosporins
How to beta lactams work?
Block cross linking of peptide chains in bacterial cell was causing cell lysis
Gram-negative aerobe, most common cause of canine UTI
E.Coli
Gram-positive aerobe, most common cause of canine pyoderma
Staphylococcus pseudintermedius
Gram-positive anaerobe, one species of this genus can cause tetanus
Clostridium
Gram-negative aerobe, can be zoonotic
Salmonella
Gram-negative aerobe that causes disease in compromised animals
Pseudomonas aeruginosa
Periodontal bacteria
Gram-positive (Peptostreptococcus) and Gram-negative anaerobes (Bacteroides, Fusobacterium)
Gram-positive anaerobe that can be isolated from abdominal fluid samples in cases of peritonitis
Actinomyces
Infections that are commonly caused by aerobes
Infections of the skin, urinary tract, cornea, external ear and blood
Infections that can be caused from pathogens in any of the 4 quadrants
Peritonitis, pyothorax, aspiration pneumonia, and infections of the middle ear and CNS
Gentamicin
-Aminoglycoside
-Primarily G- and MDR Staph. sp. Do not use for anaerobes
-Unlike other drug families, resistance to one family member does not imply resistance to another.
-Mechanism of action requires aerobic environment –> poor choice for anaerobics
-Highly water soluble, poorly lipid soluble –poor penetration of bile, prostate, brain, eye, CSF
-Highly concentrated in urine–> useful in some drug-resistant UTI
-IV, IM, SC
Dose interval= 24 hr
What are the adverse effects of Gentamicin?
Low therapeutic index, Monitoring plasma concentrations may be indicated
Neprotoxicity (esp. treatment > 3days, elderly, prior renal impairment, dehydration, hyponatremia, hypokalemia, concurrent NSAIDs, liver impairment)
Ototoxicity, vestibular toxicity
Neuromuscular blockade w some anesthetics
Amoxicillin
-b-lactam/Aminopenicilllin
-G+ aerobes/Some G- aerobes/ G+G-anaerobes
-Orally bioavailable
Lactamase sensitive
-PO 8-12 hr
Adverse effects of Amoxicillin?
Vomiting, diarrhea, inappetance
Hypersensitivity: Anaphylaxis, cytopenias
Ampicillin
-b-lactam/Aminopenicilllin
-G+ aerobes/Some G- aerobes/ G+G-anaerobes
-Poor oral bioavailability
Lactamase sensitive
-IV,IM,SC 6-8 hrs
-
Adverse effects of Ampicillin?
-Vomiting, diarrhea, inappetance
Hypersensitivity: Anaphylaxis, cytopenias
Amoxicilin-Clavulanate
- b-lactam/Aminopenicilllin + Lactamase inhibitor
- G+ aerobes/Some G- aerobes/ G+G-anaerobes
- Resistant to some lactamases
- PO q 12 hr
Adverse effects of Clavamox?
Vomiting, diarrhea, inappetance
Hypersensitivity: Anaphylaxis, cytopenias
Cephalexin
-b-lactam/Cephalosporin 1st Gen
-G+ aerobes (esp Staph, Strep), Some G- aerobes, Anaerobic activity unpredictable
-Resistant to some lactamases
Not active in MRS
-PO q 12 hr
Adverse reactions to Cephalexin?
Vomiting, diarrhea, inappetance
Hypersensitivity: Anaphylaxis, cytopenias
Cefovicin
-b-lactam/Cephalosporin 3rd Gen
-G- and G+ aerobes (more G- than 1st gen) G+G- anaerobes
-More lactamase resistant than 1st gen.
Not active in MRS
-SC q 14 days
Adverse effects of Cefovecin?
Vomiting, diarrhea, inappetance
Hypersensitivity: Anaphylaxis, cytopenias
Cefpodoxime
-b-lactam/Cephalosporin 3rd Gen
-G- and G+ aerobes (more G- than 1st gen)
-More lactamase resistant than 1st gen.
Not active in anaerobes
Not active in MRS
-PO q 24 hrs
Adverse effects of cefpodoxime?
-Vomiting, diarrhea, inappetance
Hypersensitivity: Anaphylaxis, cytopenias
Ceftiofur
-b-lactam/Cephalosporin 3rd Gen
-G- and G+ aerobes (more G- than 1st gen) G+G- anaerobes
-More lactamase resistant than 1st gen.
Not active in MRS
-SC q 24 hrs
AR to Ceftiofur?
Vomiting, diarrhea, inappetance
Hypersensitivity: Anaphylaxis, cytopenias
Penicillin G
- b-lactam/Natural Penicilllin
- G+ aerobes/ G+G-anaerobes
- IV,IM q 6-8 hr
AR to penicillin g?
Vomiting, diarrhea, inappetance
Hypersensitivity: Anaphylaxis, cytopenias
Ciprofloxacin
- Fluoroquinolone
- G- and G+ aerobes, ineffective against anaerobes
- Highly variable oral bioavailability in dog, low in cats (~25%).
- IV, PO q 24 hr
Adverse effects of ciprofloxacin?
Inappetence, vomiting
Rapid IV-> hypotension, tachycardia, erythema
CNS signs (ataxia, tremor, siezure) esp at high doses
Cartilage damage in young animals (esp > 7 days, 4-28 weeks of age)
Enrofloxacin
- Fluoroquinolone
- G- and G+ aerobes, ineffective against anaerobes
- Reduce dose/Increase interval w renal failure. Infuse diluted, and slowly for IV. Concentrated in urine.
- IV, IM, PO q 24 hr
AE of Enrofloxacin?
Inappetence, vomiting
Rapid IV-> hypotension, tachycardia, erythema
CNS signs (ataxia, tremor, siezure) esp at high doses
Blindness in cats (esp parenteral, high doses)
Cartilage damage in young animals (esp > 7 days, 4-28 weeks of age)
Marbofloxacin
- Fluoroquinolone
- G- and G+ aerobes, ineffective against anaerobes
- Reduce dose/Increase interval w renal failure. Infuse diluted, and slowly for IV. Concentrated in urine.
- PO q 24 hr
AE of Marbofloxacin?
Inappetence, vomiting
Rapid IV-> hypotension, tachycardia, erythema
CNS signs (ataxia, tremor, siezure) esp at high doses
Manufacturer research: no feline blindness adverse effect
Cartilage damage in young animals (esp > 7 days, 4-28 weeks of age)
Clindamycin
- Lincosamide
- Primarily G+ aerobes, good anaerobic coverage
- Similar coverage as erythromycin, also greater anaerobic coverage, and toxoplasmosis, neosporosis
- PO, IV, IM q 12-24 hr
AE of clindamycin?
GI effects (inappetence, nausea, vomiting) Esophageal damage with oral dosing, recommend efforts to "chase" dose with water.
Erythromycin
-Macrolide
-Primarily G+ aerobes, some anaerobes, intracellular bacteria
-Effective against many intracellular bacteria
Penetration good across tissues, except CNS and urine.
Stimulates motilin receptors –> GI prokinetic effect
-PO q 8 hrs
AE of Erythromycin?
GI effects (inappetence, nausea, vomiting) Inhibitor of P450 enzymes, risk of modifying clearance of other drugs' clearance
Tylosin
- Macrolide
- Primarily G+ aerobes, some anaerobes
- Used in antibiotic-responsive diarrhea
- PO IM q 12-24 hrs
AE of Tylosin?
Do not administer orally to rodents, rabbits, horses
Chloramphenicol
-G+ and G-, aerobes and anaerobes, some rickettsia
-Outstanding tissue penetration across tissues.
Primarily metabolized in liver –> avoid in hepatic impairment
Clients must be counseled/cautioned regarding PPE to avoid accidental exposure
-IV, IM, PO q 6-12 hrs
AE of Chloramphenicol?
GI effects common (inappetence, hypersalivation, vomiting)
Reversible bone marrow suppression (esp. high doses, prolonged treatment. Cats more susceptible vs dogs).
Potent inhibitor of P450 enzymes, risk of modifying clearance of other drugs’ clearance
Nitrofurantoin
- Nitrofuran
- G+. G- aerobes
- Primary use in UTI, where it concentrates
- PO q 8 hrs
AE of Nitrofurantoin?
GI: vomiting
Peripheral neuropathy (reversible)
Pulmonary hypersensitivity
Hepatotoxicity
Metronidazole
-Nitroimidazole
-G+ and G- anaerobes, Giardia
-Anaerobic activation of prodrug limits spectrum to anaerobes
Resistance is rare. Unpalatable for cats, but more palatable benzoate preparation available via compounding.
-PO q 12-24 hrs
AE of Metronidizole?
Neurotoxicity (lethargy, ataxia, tremors, head tilt, nystagmus, seizures), especially with high doses and/or hepatic impairment.
Inappetence, vomiting, diarrhea
Trimethoprim-Sulfamethoxazole
-Potentiated sulfonamides
-G+, G-, aerobes, some protozoa. Poor anaerobic activity
-Good prostate penetration (ion-trapped by low pH)
Highly concentrated in urine
Dogs (esp Doberman, Samoyed, Min. Schnauzer) more prone to adverse effects due to lower metabolic clearance
Poor anaerobic activity
-PO, IV q 12 hrs
AE of trimethoprim-sulfamethoxazole?
vomiting, inappetence
Hypersensitivity: KCS, pyrexia, polyarthritis, cutaneous lesions, ITP, IMHA, hepatitis, pancreatitis, nephritis, bone marrow suppression.
Hypothyroidism
Rifampin
- Rifamycin
- Staph, Strep,
- High intracellular penetration
- PO q 12 hrs
AE of Rifampin?
Vomiting, inappetence are common
Imparts a (sometimes frightening) red-range color to urine, to a lesser degree sclera, saliva
Increased liver enzymes, hepatopathy (esp high doses)
Strong inducer of hepatic enzymes, potential for substantial modification of other drugs’ clearance
Doxycycline
-Tetracycline
-G+, G-, some anaerobes, protozoa, atypical and intracellular pathogens (spirochetes, Mycoplasma spp., rickettsiae)
-Penetration good across tissues.
Concentrated in bile, urinary concentrations sufficient to treat UTI
Doxycycline can be administered with food (unlike other tetracyclines)
Unlike other tetracyclines doxycycline has less binding to Ca++, thus lower risk of bone growth impairment and tooth discoloration
PO, IV q 12-24 hrs
AE of Doxycycline?
GI effects (inappetence, nausea, vomiting) Esophageal damage with oral dosing, recommend efforts to "chase" dose with water. Potential to cause hepatic impairment and renal tubular necrosis
Itraconozole
-Azole
-Used to treat several systemic mycoses, and Malassezia.
-Resistance to one azole does not imply resistance to other azoles
Bioavailability increased with food, but poor with concurrent gastric acid suppressant drugs
Variable bioavailability –> therapeutic monitoring may be valuable
Poor CNS, urine, eye penetration
Accumulates in skin and claws –> drug of choice for dermatophytosis
Good choice for fungal osteomyelitis
PO q 12-24 hrs
AE to Itrakonozole?
GI: Inappetence, vomiting
Lethargy
Mild transaminase elevation, less commonly hepatitis
Potent inhibitor of P450 enzymes, risk of modifying clearance of other drugs’ clearance. This enzyme inhibition results in decreased testosterone and cortisol synthesis. Males may experience transient infertility.
Ketoconazole
Azole
-Used to treat several systemic mycoses, and Malassezia.
-Use has been largely replaced by itraconozole
Resistance to one azole does not imply resistance to other azoles
Bioavailability increased with food, but poor with concurrent gastric acid suppressant drugs
Poor CNS penetration
Ketoconazole P450 inhibition resulting in reduced metabolic clearance (see adverse effects) is sometimes used intentionally to reduce the required dose of more expensive drugs, ketaconazole + cyclosporine. The appropriateness of this practice is not universally considered appropriate use of an antimicrobial
PO q 12 hrs
AE of Ketokonozole?
GI: Inappetence, vomiting, diarrhea
Lethargy
Mild transaminase elevation, less commonly hepatitis
Potent inhibitor of P450 enzymes, risk of modifying clearance of other drugs’ clearance
Terbinafine
-Allylamine
-Primary activity in dermatophytes, some activity in Malassezia
-Efficacy for invasive fungal infections is unclear.
PO q 24 hrs
AE of Terbinafine?
GI: Vomiting
Increased liver enzymes
Facial pruritus (cats)
