Term
|
Definition
Sulfamethoxazole
Sulfadiazine
Sulfadimethoxine |
|
|
Term
| Sulfonomides Mechanism of Action |
|
Definition
penetrate bacteria
compete with PABA to inhibit folic acid synthesis in bacteria |
|
|
Term
|
Definition
bacteriostatic
time-dependent
decreased by pus or necrotic tissues |
|
|
Term
| Sulfonomides Spectrum of Action |
|
Definition
Gram + and Gram -
broad spectrum
aerobes only
mainly extracellular bacteria
some protozoa |
|
|
Term
| Sulfonomides Combinations |
|
Definition
| additive or synergistic activity with diaminopyrimidines |
|
|
Term
| Sulfonomides Pharmacokinetics |
|
Definition
partial oral absorptions
extracellular distribution
good penetration in fluids (CSF and prostatic secretions)
liver metabolism
mixed liver and renal elimination |
|
|
Term
| Sulfonomides Adverse Effects |
|
Definition
dose-dependent adverse effects
inhibits thyroid function in dogs (reversible)
avoid using in hypothyroid dogs or adjust T4 drugs accordingly
Keratoconjunctivitis sicca is rare in dogs
monitor tear production and avoid in dogs with chronic eye disease
very rare urinary disturbances
cytopenia (NOT dose-depedent) in combined diaminopyrimidine and sulfonamide
immune-mediated cytopenia due to sulfonamide |
|
|
Term
| Sulfonomides Allergic Reactions |
|
Definition
rare in dogs
less frequent than B-lactam allergies |
|
|
Term
| Sulfonomides Clinical Usage |
|
Definition
use carefully in dogs with hypothyroidism or with eye disease
don't use in Dobermans/Doberman pinchers unless it is life-threatening
usually used in combination with diaminopyrimidines
off-label use BANNED in lactating dairy cattle |
|
|
Term
|
Definition
end in -oprim
Trimethoprim
Ormetoprim |
|
|
Term
| Diaminopyrimidines Mechanism of Action |
|
Definition
prevents activation of folic acid to folinic acid
this inhibits RNA and DNA synthesis |
|
|
Term
| Diaminopyrimidines Activity |
|
Definition
bacteriostatic
time-dependent
more active that sulfas on their own |
|
|
Term
| Diaminopyrimidines Spectrum of Action |
|
Definition
Gram + and Gram -
broad spectrum
aerobic bacteria only
extracellular and intracellular bacteria
wider spectrum for protozoa |
|
|
Term
| Diaminopyrimidines Pharmacokinetics |
|
Definition
well absorbed orally
distributes extracellularly and intracellularly
good penetration in fluids and deep tissues
liver metabolism and excretion |
|
|
Term
| Diaminopyrimidines Adverse Effects |
|
Definition
dose-dependent side effects due to folate deficiency
blood cytopenia when used at high doses and/or for long periods of longs (reversible)
avoid in pregnant animals
can supplement with folic acid |
|
|
Term
| Potentiated Sulfonamides Group |
|
Definition
combined sulfonamides and diaminopyrimidines
Sulfamethoxale-Trimethoprim
Sulfadimethoxine-Ormetoprim
Sulfadiazine-Trimethoprim |
|
|
Term
| Reason for Potentiated Sulfonamides |
|
Definition
sequential mechanism of action in folic acid synthesis pathway
combination potentially bactericidal even though the drugs separately are bacteriostatic
extension of spectrum to intracellular microbes
extension of tissue penetration |
|
|
Term
| Potentiated Sulfonamides Activity |
|
Definition
bacteriostatic separately
bactericidal with certain bacteria and once certain concentrations are reached
time-dependent |
|
|
Term
| Nitrofurans Mechanism of Action |
|
Definition
go after energy production pathway
deprives bacteria from key energy production pathway
also damages DNA |
|
|
Term
|
Definition
|
|
Term
|
Definition
bacteriostatic or bacteriocidal
can go after 4 quadrants
Gram +, Gram -, anaerobic, aerobic, protozoa |
|
|
Term
| Nitrofurans Pharmacokinetics |
|
Definition
extracellular distribution
mainly renal excretion very quickly
get concentrated in urine in active form |
|
|
Term
| Nitrofurans Adverse Effects |
|
Definition
dose-dependent toxicity
common drug allergy |
|
|
Term
| Nitrofurans Clinical Usage |
|
Definition
locally for otitis, keratitis
systemically for UTIs with multi-resistant bacteria
BANNED in food animals |
|
|
