Lecture 23: Drugs interfering with Nucleic Acid Synthesis Flashcards
The difference between individual sulfonamide agents is based on properties such as ___
Rate of absorption, excretion and solubility in urine
What is essential for antibacterial action of sulfonamides
A free paramino group
Are sulfonamides bacteriostatic or bacteriocidal
Generally bacteriostatic but in urinary tract infections could be bacteriocidal, so good tx of UTI’s
What do sulfonamides compete with for incorporation into folic acid
Para-aminobenzoic acid (PABA)
___is an integral part of folic acid synthesis which is necessary for purine and DNA synthesis by bacteria
PABA
In presence of sulfonamides susceptible bacteria can’t __, ___ and __
Multiply, grow and survive
Why is the mechanism of sulfonamides not relevant to host/mammalian cells
Mammalian cells do not synthesize their own folic acid, they uptake it from the environment
What organisms do sulfonamides act on
Gram positive and gram negative
What organisms are highly sensitive to sulfonamides
Group A streotococci, pneumococci, E. Coli, Nocardia, Actinomyces, Chlamydria, Pneumocytis jiroveci
What is sulfamethazine used for
- Bacterial pneumonia and BRD
- Foot rot and diphtheria in cattle
- Acute mastitis in cattle
- Bacterial pneumonia in swine
- Coccidiosis in chickens
What is sulfadmiethoxine used for
Coccidiosis
Which sulfonamide at high doses can precipitate in urine and cause damage to kidney
Sulfadimethoxine
Which sulfonamide is approved orally in calves (except veal calves) under 1 month of age and swine for tx of respiratory and enteric infections, especially colibacilliosis
Sulfachlorpryidazine
What is the only sulfonamide that can be prepared as the sodium salt at neutral pH and thus can be used in ophthalmic preparations
Sulfectamide
What is sulfasazline used for
Enteric sulfonamide used for tx of colitis and IBD in dogs and cats
In the large bowel what is sulfasazline cleaved into and what are their specific functions
- Sulfapyridine- antibacterial agent and RA
- 5-ASA- anti-inflammatory (ulcerative colitis)
What are potentiated sulfonamides mixed with
Trimethoprim or ormetoprim
Are potentiated sulfonamides bacteriostatic or bacteriocidal
Bacteriocidal
How do potentiated sulfonamides change the spectrum of action and resistance
Broad spectrum and decrease development of resistance
Trimpethoprim concentrates in ___ in dogs and is used against ___
Prostate, prostatitis