Quinolones, Folic acid antagonists and Urinary antiseptics Flashcards
Fluoroquinolone targets _________ in Gram negatives and _________ in Gram positive bacteria
DNA gyrase, topoisomerase IV
Name 3 fluoroquinolones
ciprofloxacin, levofloxacin, moxifloxacin
Fluroquinolones should be administered at least _________ hours before consumption of dairy products or substances that contain divalent cations
2 hours
Best on empty stomach
Name the two respiratory quinolones
Levofloxacin and moxifloxacin
Name at least 3 adverse effects associated with the use of fluroquinolones.
- Phototoxicity
- Tendinitis or tendon rupture
- Prolong QT interval
- Peripheral Neuropathy
- GI distress
- Arthropathy
Which antibiotics are known to cause phototoxicity?
Tetracyclines, fluoroquinolones
Fluoroquinolones are contraindicated in _________
- Children < 18 years old
2. Pregnant women
Can fluoroquinolones be used when breastfeeding?
No
Name 3 folate synthesis inhibitors
Sulfonamides, trimethoprim, cotrimoxazole
Folic acid is vitamin B9 that is needed in humans to produce healthy ___________
red blood cells
Which enzyme does sulfonamide inhibit?
Dihydropteroate synthase
Sulfonamides are only effective in bacteria that synthesize their own __________?
folic acid
Sulfonamides can cause nephrotoxicity as a result of __________?
crystalluria
G6PD deficient patients using sulfonamides can suffer from __________
hemolytic anemia
Usage of sulfonamides in last trimester can cause __________ in newborns
kernicterus
Which enzyme does trimethoprim inhibit?
Dihydrofolate reductase
Trimethoprim can cause __________ deficiency in humans
folic acid
Folic acid deficiency caused by trimethoprim can be managed by giving the patients _____________ .
Folinic acid
Cotrimoxazole is a combination of which 2 antibiotics, and in what ratio?
Trimethoprim and sulfamethoxazole, 1:5 respectively
Name an antibiotic which is used as the choice of drug for the management of pneumocystis pneumonia
Cotrimoxazole
Cotrimoxazole is contraindicated in which trimester(s) of pregnancy?
First and last trimester
Name at LEAST two indications for cotrimoxazole
- UTI
- Pneumocystis jirovecii pnneumonia
2. Pneumocystis pneumonia
Name at LEAST 3 adverse effects related to the use of cotrimoxazole
- GI related adverse effects like nausea, vomitting, CDAD
- Rash
- Photosensitivity
- Blood disorders including megaloblastic anemia, leukopenia, and thrombocytopenia
- Haemolytic anaemia in G6PD deficient patients
What is nitrofurantoin’s mechanism of action?
It is converted by the bacteria to a highly active intermediate, which disrupts the synthesis of DNA, RNA and metabolic processes.
Nitrofurantoin is effective in treatment of _________ .
lower UTI
Nitrofurantoin can cause urine colour to turn _________ .
brown
How is nitrofurantoin cleared?
Renal clearance
G6PD deficient patients using nitrofurantoin are susceptible to ___________ .
Hematologic disturbances such as hemolytic anemia, leukopenia
What is G6PD, and why is it important in red blood cells?
The glucose-6-phosphate dehydrogenase (G6PD) enzyme is the central factor of the antioxidant defense system in red blood cells, which helps maintain high levels of reduced glutathione (GSH) and nicotine adenine dinucleotide phosphate (NADPH), to protect the RBC from oxidative damage caused by reactive oxygen species.
Name 3 groups of patients in whom nitrofurantoin may be contraindicated.
- Patients with impaired renal function
- Pregnant women (at term > 37 weeks)
- Infants <1 mth of age
What would be examples of recommended treatment options for simple UTI in healthy women of reproductive age?
- Cotrimoxazole
2. Nitrofurantoin
Name an antibiotic that can be administered orally for the management of Pseudomonas aeruginosa
Ciprofloxacin
Can ciprofloxacin be used in the management of MRSA infections?
No, due to high rates of resistance.
