Quinolones, Folic Acid (Folate) Antagonists and Urinary Tract Antiseptics Flashcards
4th generation; anaerobic and gram pos activity
Moxifloxacin
Avoid ingestion of dairy, sucralfate, aluminum / magnesium containing antacids, iron, zinc, calcium (2 hours before / 3 hours after taking)
Fluoroquinolones
Adjust dosages for renal impairment.
Quinolones
Dyspnea, chest pains, chills, fever, cough
Hematologic - especially in G-6-PD
Peripheral Neuropathy
Hepatotoxicity
Birth defects
CNS Effects
Adverse effects of Nitrofurantoin
Generally well tolerated
N/V/D , headache, dizziness, lightheadedness, confusion, Phototoxicity
Use caution in CNS disorders, Peripheral neuropathy, Glucose dysregulation (Hypo/hyperglycemia)
Prolongation of QT interval.
Increases serum concentrations of Theophylline, Warfarin, Caffeine,Cyclosporine
Adverse Effects / Drug Interactions of Fluoroquinolones
Sulfonamides, trimethoprim and cotrimoxazole are all …
Folate antagonists
(Birth defects possible, especially it taken during the first trimester and near term)
Secreted in breast milk (<2 months old can cause kernicterus)
It is a preferred drug for UTIs and is the drug of choice for PCP in patients with AIDs and other immunodeficiencies.
Cotrimoxazole (bactrim, TMP/SMZ)
Fluoroquinolones are commonly considered as …
alternatives for patients with documented SEVERE B-lactam allergies
Folic acid deficiency: You can ____ it by giving folic acid to patients.
1 mg/day folic acid with prenatal vitamin regimen (at a min)
reverse
Shows improved gram-pos coverage, maintains gram-neg activity and gains ANAEROBIC coverage.
Fourth generation of Fluoroquinolones
The first drugs available for systemic treatment of bacterial infections. Introduced in the 1930s.
Usage declined once PCN was introduced in the 1940s.
Older agents had low solubility which caused urine crystallization and kidney injury. Newer agents are more water soluble which decreases renal risk.
Primarily used and often preferred for acute UTIs (90% are due to Escherichia coli)
Sulfonamides
Resistance of fluoroquinolones comes from an ____ in DNA gyrase and topoisomerase 4.
Alteration
Achieves high levels in bone, urine (except which quinolone…?), kidney, prostatic tissue, lungs. Low CSF penetration except _____ (low urine levels, not for UTI).
ofloxacin
Avoid _____ with decreased renal fxn.
Nitrofurantoin
Enhanced activity against gram + (S. pneumoniae) + excellent activity against many anaerobes
Poor activity against P. aeruginosa, resistant to Bacteroides fragilis
CAP, nosocomial pneumonia
Not indicated for UTIs due to poor concentration in the urine*
Moxifloxacin (respiratory quinolone)
Most quinolones are excreted renally.
Adjust dosage in renal impairment (except _____, which is excreted by the liver)
moxifloxacin
Accumulates and has activity against intracellular organisms (effective against _____ and mycobacteria)
chlamydia
These are less used today, have moderate gram-negative, minimal serum concentrations, restricted to the treatment of UNCOMPLICATED UTIs.
First generation of Fluoroquinolones
What enzyme does Sulfonamides inhibit? dihydropteroate ______.
synthase
precedes all fluoroquinolones and are not clinically used
Naldixic Acid
Retain expanded gram-negative activity and show improved activity against atypical organisms and specific gram-pos bacteria.
Third generation of Fluoroquinolones
____ is required by all cells to make DNA, RNA, and proteins
Folate antagonists inhibit sequential steps in the synthesis of tetrahydrofolic acid. In the absence of _____, bacteria are unable to synthesize DNA, RNA and proteins
Folate; tetrahydrofolate
Ampicillin and Gentamicin
Infant UTI tx
Resistance is due to an alteration in dihydrofolate reductase that has a lower affinity for trimethoprim+ efflux pumps and decreased drug permeability.
Rapidly absorbed after oral administration.
High concentrations are achieved in prostatic and vaginal fluids and CSF.
Can produce effects of folic acid deficiency:
- Megaloblastic anemia
- Leukopenia
- Granulocytopenia
Trimethoprim
If breast feeding, avoid ____. Avoid Trimeth/Sulfa also in early stages of infancy.
Nitrofurantoin
What enzyme does Trimethoprim inhibit? dihydrofolate _____.
reductase
Sulfamethoxazole + Trimethoprim = greater activity together than each working individually.
Cotrimoxazole (bactrim, TMP/SMZ)