Quinolones, Folic Acid antagonists and urinary antiseptics Flashcards by eden leow

Name the 6 Fluoroquinolones

ciprofloxacin
levofloxacin 
moxifloxacin 
nalidixic acid 
norfloxacin 
ofloxacin

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What infection is fluoroquinolone closely tied to

CDAD

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Fluoroquinolone antibiotics targets ______, primarily in gram-_____ bacteria and ______________ in gram_____ bacteria to inhibit DNA __________

DNA gyrase, negative, topoisomerase IV, positive, replication

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Ingestion of fluoroquinolone with calcium or other divalent cations can ______ absorption

reduce

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Fluoroquinolone should be taken on a full/empty stomach

empty

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clearance of fluoroquinolone

renal

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levels of fluoroquinolone are high in….

bones, urine, kidney, prostatic tissue and lungs

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Moxifloxacin is mainly metabolised by

liver

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Cipro is most active against gram-___ strains and ____________

neg, enteric coliform

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Cipro is active against penicillin, cephalosporin and amino glycoside-resistant strains

yes

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Cipro is highly active against _____ and is commonly used in ___________ patients

P. aeruginosa, cystic fibrosis

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Cipro is used in what type of infections?

skin, bone, joint

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Name 5 indications for cipro

cystic fibrosis 
travellers diarrhoea (e.coli) 
food poisoning (enterobacteriaceae and campylobacter jejune) 
typhoid fever (salmonella typhi) 
UTI
prostatitis

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Is cipro the first line agent for simple UTI?

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3rd gen fluoroquiinolones like levy and maxi have better coverage agains gram _____ organisms especially _________ and ________

positive, S.pneumoniae, atypical pathogens

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3rd gen fluoroquinolone are useful against ________ infections

respiratory

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common ADR of fluoroquinolone

nausea, vomiting, diarrhoea, phototoxicity

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Serious ADR of fluoroquinolone

tendinitis or tondon rupture
prolong QTc interval (3rd gen) –> not in patients predisposed to arrhythmias or taking other medications cause QT
peripheral neuropathy

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Fluoroquinolone in children?

no <18 yo

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Fluoroquinolone in preggo and breastfeeding

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Fluoroquinolone contraindication

myasthenia graves

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co administration of a sulfonamide and trimethoprim introduces sequential blocks in the biosynthetic pathway for _______ –> synergistic effect –> bacteri____ effect

tetrahydrofolate, cidal

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sulphonamides are competitive inhibitors of ___________

dihydropteroate synthase

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Bacteriostasis induced by sulphonamides is counteracted by ____ competitively

PABA

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Name the 2 intermediate acting sulfonamides

sulfamethoxazole | sulfadiazine

sulfonamides administration

oral (except sulfasalazine)

sulfonamides CSF?

yes even in the absence of inflammation

sulfonamides metabolism

acetylated and conjugated primarily in the liver. Acetylated product can precipitate at neutral or acidic pH and cause crystalluria -->damage kidneys

sulfonamides clinicsal indications

combined with trimethoprim for pneumocystis carinii combined with pyrimethamine for drug resistant malaria IBS infected burns (topically) resp infections (eg with Nocardia)

ADR of sulfonamides

Crystalluria hypersensitivity with sulfa allergy hematopoietic disturbances kernicterus in newborns if mom takes in late preggo

sulfonamides preggo?

avoided in newborns and infants less than 2months of age and pregnant women at term

Trimethoprim is a potent inhibitor of __________

bacterial dihydrofolate reductase

Trimethoprim leads to a decreased availability of tetrahydrofolate cofactors required for ___, ______ and ______ synthesis

purine, pyrimidine and AA

Trimethoprim may be used alone in the treatment of __ and ________________

UTI and bacterial prostatitis

modes of resistance in Trimethoprim

resistance in gram nag bacteria presence of altered dihydrofolate reductase --> lower affinity for trimethoprim efflux pumps and decreased perm to the drug

Trimethoprim administration

oral

Higher concentrations of Trimethoprim are achieved in the

vagina and prostate

Trimethoprim CSF?

yes

Trimethoprim Excretion

renal

Trimethoprim ADR

folic acid deficiency | - megaloblastic anemia, leukopenia, granulocytopenia

Trimethoprim preggo?

cat c

how to manage folic acid deficiency with Trimethoprim

simultaneous administration folinic acid

Trimethoprim is most often compounded with ____ producing the combination _________

sulfamethoxazole, cotrimoxazole

cotrimoxazole inhibits 2 sequential steps in the ________

synthesis of tetrahydrofolic acid

cotrimoxazole administration

oral (full cup of water) | IV for patients with severe pneumonia

cotrimoxazole CSF?

yes

cotrimoxazole clearance?

renal

cotrimoxazole indications? 5 indications

URI, E.coli resp infections caused by haemophilia sp, mortadella catarrhal is and Klebsiella pneumonia Toxoplasmosis MRSA and community acquired skin and soft tissue infections pneumocystis pneumonia caused by pneumocystis jiroveci

cotrimoxazole MRSA?

yes

Trimethoprim MRSA?

Name 3 ADR of cotrimoxazole

``` rashes photosensitivity GI haemolytic anemia inpatients with G6PD deficiency folic acid deficiency ```

Nitrofurantoin MOA?

bacteria reduce the drug to an active intermediate that inhibits various enzymes and disrupt the synthesis of proteins, DNA, RNA and metabolic processes

Nitrofurantoin active against many strains of....

E.coli and enterococci

what species are resistant to Nitrofurantoin

proteus and pseudomonas and many species of enterobacter and Klebsiella

Nitrofurantoin administration

oral

Nitrofurantoin distribution

high urinary concentrations while limiting systemic exposure due to rapid clearance (good for UTIs)

Name 4 Nitrofurantoin ADR

N/V hypersensitivity G6PD deficiency elderly patients susceptible to pulmonary toxicity of nitrofurantoin peripheral neuropathies for renal patients

Nitrofurantoin contraindications

impaired Bernal function (CrCl < 40mL/min) late preggo, labour and delivery infants < 1m

Polymyxins is active against most gram ___ bacteria

neg

Types of polymyxins?

colistin and polymyxin B

polymyxin B is administered as a prodrug

false

Colistin is administered as an inactive prodrug

True

polymyxins are bacteriostatic

false

gram neg bacteria are more sensitive than gram positive bacteria to polymyxins

True

Polymyxins are mostly used against gram ___ bacteria

neg

polymyxins are not active against....

``` proteus spp. legionella campylobacter vibrio cholera gram neg cocci gram positive bacteria anaerobic ```

2 clinical uses of polymyxins

inhaled CMS for pseudomonas resp infections polymyxin B: acute infections due to MDR gram neg microbes with no alternatives - UTI and blood stream infections due to P.aeruginosa

Polymyxin B administration

CMS administration

inhalation or IV

polymyxins ADR (name 3)

nephrotoxicity neurotoxicity aerosolised reactions (chest tightness, sore throat etc)

Fosfomycin is bacteriostatic

False

Fosfomycin has activity against gram positive only

False (pos and neg)

Fosfomycin MOA

interferes with cell wall synthesis by inhibiting the initial step involving phosphoenolpyrivate synthesise

Fosfomycin highly active against which gram positive pathogens?

S.aureus and enterococcus

Fosfomycin highly active against which gram positive pathogens?

P. aeruginosa and Klesiella pneumoniae

Fosfomycin mainly used in the treatment of ___

UTI

Fosfomycin has synergistic effect with _____

betalactams

Fosfomycin administration

Fosfomycin tromethamine: oral | best taken on empty stomach

Fosfomycin CSF?

yes

Fosfomycin enters breast milk?

yes

Fosfomycin 3 ADRs?

GI headache vaginitis

Fosfomycin clearance

renal

Anti-protozoal agent (metronidazole) administration

completely and rapidly absorbed after oral administration

metronidazole CSF?

yes

metronidazole breast milk?

yes

metronidazole metabolism?

hepatic

metronidazole elimination?

renal

Name 4 ADR of metronidazole

GI metallic taste oral moniliasis CNS (seizures, optic anad peripheral neuropathy)

metronidazole preggo?

cat b but avoid in 1st trimester