Nucleic Acid Synthesis Inhibitors Flashcards
3 general indirect nucleic acid synthesis inhibitors
Sulfonamides
Trimethoprim
Pyrimethamine
Sulfonamides are
Bacteriostatic/Bactericidal?
Bacteriostatic
Sulfonamides spectrum
S. E. H. K. S. S. E. T. PJ. VC. N. C.
Poor activity against______
Strep pyogenes, E. coli. H influenza, Klebsiella, salmonella, shigella, Enterobacter, toxoplasma, p jiroveci, vibrio cholera, nocardia, chlamydia
Poor against anaerobes
Sulfonamides inhibit what enzyme?
Dihydropteroate synthase
Sulfonamides are metabolized by _________and _________ in the liver.
acetylation and glucuronidation
Sulfonamides are ____soluble/insoluble in acid urine
Insoluble - drink plenty of water
What class of drugs cause crystalluria?
Sulfonamides
Oral sulfonamides (4)
Sulfisoxazole, sulfadiazine, sulfamethoxazole, sulfadoxine
Oral non-absorbable agents (1)
Sulfasalazine
Topic sulfonamide agents (3)
Sulfacetamide
Mafenide
Silver sulfadiazine
Drug(s) of choice to treat PCP in AIDS patients
Sulfamethoxazole and trimethoprim (cotrimoxazole)
Sulfonamide in combo with ______ to treat Malaria
Sulfadoxine & pyrimethamine
Sulfonamide used with _______ to treat toxoplasmosis?
Sulfadiazine & pyrimethamine
Sulfapyridine is combined with __________ for treatment of ulcerative colitis and rheumatoid arthritis
5-aminosalicylic acid
Sulfonamide used with _______ to treat P. jiroveci pneumonia
Sulfamethoxazole & trimethoprim
Sulfonamide used to treat eye infections used topically
Sulfacetamide
Mafenide can cause ______ and its use should be limited in burn patients
Metabolic acidosis
Topical sulfonamide that release silver ions to exhibit anti-microbial action
Silver sulfadiazine
Silver sulfadiazine is used in _________and preferred over mafenide for preventions of infection
Burn dressings and ulcers
Trimethoprim inhibits which enzyme?
Dihydrofolate reductase
Trimethoprim is used best to treat ______ because it concentrates in ____
Acute UTI’s because it’s acidic
In someone with G6PD deficiency taking sulfonamides, they should be careful of ____.
Hemolysis
Fixed dose combination of trimethoprim and sulfamethoxazole is called____?
Cotrimoxazole
Spectrum of Cotrimoxazole
S aureus (MRSA strains) S pneumonia H influenzae Klebsiella pneumonia E. Coli Salmonella Shigella Toxoplasma P. jiroveci
Dose ratio of cotrimoxazole
5:1
Therapeutic Uses of Cotrimoxazole
UTIs DoC in Nocardia DoC in P. jiroveci RTIs Typhoid fever Bacterial diarrhea
Resistance to sulfamethoxazole (3 ways)
Overproduction of PABA
Lower affinity dihydropteroate synthase
Impair permeability
Direct inhibitors of nucleic acid synthesis
Quinolones
Fluoroquinolones
Nalidixic acid is active against
Gram - bacteria E. Coli Proteus Klebsiella Shigella
Topoisomerase IV mechanism? Inhibited by?
Separates replicated chromosomal DNA into the respective daughter cells.
Fluoroquinolone
Binding of Fluoroquinolone to both the enzymes and DNA forms a complex that _____________________.
Inhibits the resealing step and can cause cell death by inducing cleavage of DNA
Fluoroquinolones should be taken ____hours before and ____hours after _______products
2 hrs; 4 hrs; cation containing
You should reduce dose of fluoroquinolones in renal dysfunction except
Moxifloxacin
2 fluoroquinolones used in typhoid fever
Ciprofloxacin
Levofloxacin
Fluoroquinolones are used in skin, soft tissues and bone infection except
Norfloxacin
3 respiratory fluoroquinolones
Levo, Gemi, and Moxifloxacin
Plasma concentrations of theophylline, warfarin are increased by 2 FQs
Ciprofloxacin
Ofloxacin
In terms of bacterial resistance, ________ can inactivate Ciprofloxacin
Aminoglycoside acetyltransferase
