Test-2-Sulfa Drugs Flashcards
PRONTOSIL
Sulfonamids
CHRYSOIDEN
*ANTIBACTERIAL IN VIVO due to activation in the liver.
Need to break double Nitrogen bond.
SULFANILAMIDE
Sulfa drugs
Liver breaks double bonded Nitrogen to create active agent.
If the bacteria make the folic acid, they are susceptible to sulfonamides.
Works better in vitro -> due to permeability issues.
POSTULATED “PABA” antagonist (Para-Aminobenzoic Acid). COMPETITIVE
Dyhydropteroate synthetase (or coupling enzyme) is the enzyme that is inhibited. This enzyme is what makes the Folic acid reduced to 2 and then 4 H’s on it. Thats what activates it for DNA synthesis, repair, etc.
Highly bound to proteins. -> Warfarin, Anti-psycotics are unbound and are much more active as a result.
TISSUES CONTAIN AZO REDUCTASE
Methotrexate
Also a Sulfonamide, but too toxic for Antibiotic action.
Similar action as a sulfa drug, i.e. it inhibits Folic Acid from being reduced via dihydrofolate reductase.
Toxicities:
**GI EPITHELIUM – ULCERS
**BONE MARROW DEPRESSION
**NEPHROTOXICITY
Chronic Toxicity:
**LIVER (HEPATIC FIBROSIS / CIRRHOSIS)
*LUNG (PNEUMONITIS - RARE)
Small Antifolates
Examples: Trimethoprim.
Add a Ketone group to Thyamine. Very low toxicity compared to others.
Chloroguanide is an anti-malarial drug.
Mechanism of action, same as Methotrexate, binds irreversiblly to dihydrofolate Reductase.
Toxicity: *MEGALOBLASTIC ANEMIA
Can be used synergistically with Sulfa drugs due to different step in the process of Folic Acid production being impacted.
Excreted in the urine.
Uses for Combo:
**URINARY TRACT INFECTIONS
*PROSTATITIS
FLUOROQUINOLONES
CIPROFLOXACIN
LEVOFLOXACIN
Mech of action:
INHIBIT DNA GYRASE (TOPOISOMERASE II) OR TOPOISOMERASE IV. No effect on mamaillian DNA synthesis.
Uses:
*RESPIRATORY TRACT INFECTIONS (SERIOUS)
**BONE, JOINT AND SOFT TISSUE INFECTIONS
*URINARY TRACT PATHOGENS
*ANTHRAX (2001)
Currently there is some controversy over use for Cattle and Feed lots. -> Resistant strains.
*Metabolized in the Liver.
Toxicity:
**GI (NAUSEA, VOMITING, DIARRHEA) – Can get kind of serious.
**CRYSTALLURIA – DRINK WATER ??
*****CARTILEGE DAMAGE **
***TENDINITIS -> TENDON RUPTURE
NITROFURANTOIN
**DURATION – MONTHS (14 DAY INTERVALS)
**DO NOT USE IN SEVERE RENAL INSUFFICIENCY
Urine is a Red-Brown color (used for Lower UTIs)
Toxicity:
**GASTROINTESTINAL EFFECTS
