1. AMINOGLYCOSIDES -Used with serious gram negative bacterial infections
-suffix –micin or –mycin (exception: Amikacin)
NOTE: tetracyclines also use –mycin
Amikacin
Injection
Gentamicin
Topical, injectable
Neomycin
Topical, oral
AMINOGLYCOSIDES

2. -Bactericidal by affecting the ability of bacteria’s ribosomes to assemble proteins
-Aminoglycosides must be inside the bacterial cell to produce its effects and oxygen must be present for Aminoglycosides to enter
Ineffective against anaerobic bacteria and in areas lacking oxygen (colon, deep puncture wounds)
The concurrent use penicillin enhances the ability of Aminoglycosides to enter
-Once daily dosing is safest
AMINOGLYCOSIDES

3. AMINOGLYCOSIDES -Absorbed well through skin that is not intact
-Pyogenic infections limit the action of Aminoglycosides as the medication will bind to the debris instead of the body’s cells. Clean wound first.
NEPHROTOXOCITY and OTOTOXICITY are side effects of normal, high, or frequent doses as Aminoglycosides accumulate in the kidneys and inner ear (this can also be true for fetuses as they easily cross the placenta)
Nephrotoxicity may be reversible if the drug is reduced /withdrawn before there is necrosis in the tubules
Accumulation in the inner ear can cause deafness
Ototoxicity can also affect balance
AMINOGLYCOSIDES

4. FLUOROQUINOLONES (QUINOLONES)
-Most have –floxacin as a suffix
Ciprofloxacin (Cipro)
Oral and injectable
Used in small and large animals
Enrofloxacin (Baytril)
Oral, Injectable, and topical
Marbofloxacin (Zeniquin)
Oral
Used in small animals
Orbifloxacin (Orbax)
FLUOROQUINOLONES (QUINOLONES)

5. QUINOLONE MECHANISM OF ACTION
-Interfere with bacterial DNA which must be tightly coiled. Quinolone attack the bacteria's enzyme gyrase whose role is to supercoil
-Bactericidal
-Effective against common gram negative and positive bacteria (except Strep)
-Used for skin, urinary, prostatic, and respiratory infections
-Absorbed better when administered orally in small animals and by injection in large animals
QUINOLONE MECHANISM OF ACTION

6. -Can cause bubblelike lesions in rapidly growing cartilage
-Can cause bubblelike lesions in rapidly growing cartilage. Degenerate and arthritic changes can arise as adults
contraindicated In growing animals
-High doses in cats can cause changes in the retina, leading to blindness
-Reserve for serious infections as bacterial resistance is a problem
-Fluoroquinolones cannot be used extra-label on food animals
FLUOROQUINOLONES

7. TETRACYCLINES -Used in large and small animals
-Used to TX: RMSF, ehrlichiosis, salmon poisoning, hemobartonellosis, mycoplasma pneumonia, Chlamydia, psittacosis, Lyme disease
-cycline suffix
-Older tetracyclines: tetracycline and oxytetracycline, newer tetracyclines: doxycycline, minocycline
TETRACYCLINES

8. TETRACYCLINES -Bacteriostatic
-Bind to bacterial ribosomes and prevent RNA from attaching. This stops protein synthesis.
Inhibit cellular function and division.
Rely on the body having a functional immune system since they are Bacteriostatic
TETRACYCLINES

9. TETRACYCLINE PRECAUTIONS
Chelators of calcium which can effect developing teeth and bones
If given to young, growing animals both can be effected
Dentin and enamel formation can be disrupted and a yellow discoloration may develop
Bone development can be slowed if calcium is chelated
GI upset may be seen with oral administration
Normal flora in rumen can be killed off causing rumen inactivity
Irritation of GI mucosa in dogs causing V/D, anorexia
Cats are susceptible to esophageal stricture- chase with at least 6 mL water
TETRACYCLINE PRECAUTIONS

10. TETRACYCLINE PRECAUTIONS
DO NOT GIVE IV TO HORSES
Arrythmias, collapse, and death
Give slowly IV to other species
Expired tetracycline and oxytetracycline can form a nephrotoxic compound that damages the PCT.
Causes FANCONI’S SYNDROME- glucose reabsorption is impaired.
Glucosuria without hyperglycemia
TETRACYCLINE PRECAUTIONS

11. SULFONAMIDES & POTENTIATED SULFAS
AKA Sulfa drugs
Resistance is seen because of overuse
Often potentiated to increase efficacy and make them bactericidal (otherwise Bacteriostatic)
Trimethoprim and ormetoprim
Commonly used sulfa drugs:
Sulfadimethoxine (Albon, combined with ormetoprim in Primor)
Sulfadiazine (combined with trimethoprim in Tribrissen)
Sulfasalazine (GI)
SULFONAMIDES & POTENTIATED SULFAS

12. BACTERIOSTATIC: organisms that make their own folic acid needed for protein and nucleic acid metabolism. Sulfonamides block an enzyme needed for this process. Potentiators block different enzymes, but still those that are required for folic acid. When combined, the compound is BACTERICIDAL.
Broad spectrum: many G+ and G- bacteria, coccidian, and Toxopasma
Often used for UTIs.
SULFONAMIDES

13. Sulfonamides are known to produce keratoconjunctivitis sicca in dogs
Sulfonamides are known to produce keratoconjunctivitis sicca in dogs. It is often not reversible.
Skin reactions may be seen.
Thrombocytopenia and Leukopenia in small animals can occur.
Crystalluria can occur which can damage renal tubules and lead to renal failure.
Carnivores are more likely than herbivores.
Likeliness increases if dehydrated
Oral sulfa can cause salivation in cats if tablet breaks in mouth.
SULFONAMIDES

14. LINCOSAMIDES Clindamycin (Antirobe), lincomycin (Lincosin)
Bacteriostatic or bactericidal by affecting protein synthesis. Action depends on concentration at infection site.
Gram +, anaerobes, and Toxoplasma
Contraindicated to use in horses, ruminants, hamsters, guinea pigs, rabbits. Can cause serious GI issues and death.
Clindamycin is often used for dental infections, deep pyodermas, accesses, bite wounds, osteomyelitis
LINCOSAMIDES

15. Erythromycin, azithromycin (Zithromax), tilmicosin (Micotil), tylosin (Tylan)
Tylosin and tilmicosin are primarily used in cattle.
Bacteriostatic by inhibiting protein synthesis
Stimulates intestinal motility so cramping is common
Erythromycin can cause fatal diarrhea in horses
MACROLIDES

16. METRONIDAZOLE AKA Flagyl
Bactericidal, possibly by effecting DNA synthesis
Effective against protozoa, including Giardia and Trichomonas. Good for treating infections in bowel or deep wounds.
Neurological side effects can be seen with high doses or prolonged treatment.
METRONIDAZOLE

17. Low concentrations are bacteriostatic, high are bactericidal
Disrupts protein synthesis
Cannot be used in food animals
Can cause aplastic anemia in humans
Avoid inhaling powder, wash hands, wear gloves
CHLORAMPHENICOL

18. GRISEOFULVIN: oral med used to treat dermatophytes (ringworm)
Known for being teratogenic in cats. Do not use in pregnant animals. Use caution when handling if pregnant.
AMPHOTERICIN B: IV med for deep or systemic infections
Rapid onset of action
Nephrotoxicity is extremely common and dose related. Monitor BUN and creatinine every time.
ANTIFUNGALS

19. AZOLES: oral (ketoconazole, itraconazole, and fluconazole) or topical (miconazole, clotrimazole) meds for deep or systemic infections
Usually used before Amphotericin B because side effects are fewer
Topical meds are used for dermatophytosis, topical yeast infections
GI side effects are common with oral meds
Hepatotoxicity is an issue with ketoconazole
ANTIFUNGALS