Antibiotics Flashcards
Moxifloxacin
fluoroquinolone
T1/2 8-9h
Hepatically excreted - good in renal failure
1st gen cephalosporins
cefazolin, cefalexin
gram +ve only, similar cover to fluclox
2nd gen cephalosporins
cefuroxime, cefaclor
+ve and -ve
3rd gen cephalosporins
Cefotaxime, ceftriaxone
+ve, -ve, cross BBB
Ceftazidime - also pseudomonas (although limited +ve)
4th gen cephalosporins
cefipime
+ve, -ve, pseudomonas
most resistance to betalactamases
Penicillin resistance
Beta lactamase
Efflux pumps
Modification binding site
Penetration impaired
Macrolide resistance
Permeability dec
Efflux inc
Esterase production
Ribosomal binding altered
Gentamicin resistance
Transferase inactivates drug
Cell entry impaired
Ribosomal receptor altered
Treatment plasmodium ovale or vivax
chloroquine (live, not in tissue) + primaquine (kills dormant liver)
Side effects quinidine
prolonged QT, cinconism, black water fever, inc serum warfarin and digoxin, haemolysis in G6PD
ethambutol side effects
optic neuritis, retinal damage
Side effects pyrazinimide
hepatotoxicity, hyperuricaemia
aminoglycosides side effects
neuromuscular blockade and resp paralysis reversed by calcium gluconate
Isoniazid side effects
hepatitis, peripheral neuropathy due to B6 depletion
Live vaccines
MMR
Rotavirus
Chickenpox
Zoster
Bacillus calmette
Oral typhoid
Yellow fever
Pentamidine
pneumocystosis prophylaxis (antiprotozoal)
can cause diabetes
Antiprotozoal side effects
headache, ataxia, peripheral neuropathy, rash
Mechanism antihelminthics
inhibit tubulin polymerisation interfering microtubule formation
Meningococcal prophylaxis
rifampicin
GBS prophylaxis
ampicillin
Pneumocytis pneumonia prophylaxis
cotrimoxazole
mycobacterium avium complex prophylaxis
azithromycin
Rifaximin
RNA polymerase inhibitor
bacteriocidal gram +ve and negative
Tx travellers diarrhoea, hepatic encephalopathy
Fluoroquinolones mechanism and example
DNA gyrase inhibitor
ciprofloxacin
Fluoroquinolone SEs
rash, nv, deranged LFTs, cartilage (don’t give <18), enzyme inhibitor, inc QTc
PenG excretion
10% filtration 90% tubular secretion
Carbapenem MOA
beta lactamase, inhibits cell wall synthesis
e.g. meropenem
Carbapenem that doesn’t cover pseudomonas
ertapenem (n.b. none cover MRSA)
Glycopeptide antibiotic MOA and example
inhibits cell wall synth by inhibiting cross linking cell wall
vancomycin
side effects vancomycin
red man syndrome if given fast
nephrotoxicity
Aminoglycosides MOA and example
30s can be bacteriocidal
genatmicin
concentration dependant killing + post antibiotic effect
Tetracycline SE
GI, hepatotoxicity, less well absorbed with food,bone + teeth
Macrolide example and adverse effects
erythromycin
GI, inc QTc, acute hepatitis, enzyme inhibitor
Trimethoprim mechanism
dihydrofolate reductase inhibitor
folate antagonist blocks purine production and nucleic acid synth
Trimethoprim PK
A: F1
D: Wide high vD, lipid solube
T1/2 8h with sulfonamide, 11 alone
E: renal 70% unchanged
Trimethoprim SEs
rash, fever, bone marrow supression, hyprekalaemia,
sulfonamides SJS
Metronidazole mechanism
disrupts electron transport chain in DNA
SE metronidazole
metallic taste, neuropathy, seizures, thrombophlebitis
Isoniazid mechanism
inhibits cell wall mycolic acid synthesis
Rifampicin mechanism
RNA polymerase inhibitor, bacteriocidal
Rifampicin side effects
rash, nephritis, thrombocytopenia, cholestasis, orange body fluids
Pyrazinimide mechanism
disrupts cell membrane, bacteriostatic
Ethambutol SEs
retrobulbar neuritis
Amphotericin B mechanism
forms pores in fungal membranes
half life 2 weeks
SEs amphotericin B
infusion reaction, renal impairment, fever, headache, confusion
Azoles
block fungal p450 and interact with cell wall synthesis
increase QTc, deranged LFTs
Aciclovir MOA
guanasine analogue
binds to viral DNA polymerase inhibiting synthesis
Zidovudine
AZT
NRTI
T1/2 1-3h, P0.6, wide vD, 35%PB
SE myelosuppression and macrocytic anaemia
Itraconazole excretion
> 50% faeces
Penicillins resistant to betlactamases
methicillin, nafcillin
cmv tx
ganciclovir
rifampicin excretion
faecal
Penicillins not requiring dose adjustment in renal failure
dicloxacillin, oxacillin, cloxacillin, nafcillin (renal and biliary excretion)
Hepatically excreted 3rd gen cephalosporins
ceftriaxone, cefoperazone
Antibiotics resistant to staphylococcal beta lactamases
cloxacillin
naficillin
methicillin (not used as renal toxic)
Anti pseudomonal cephalosporins
Ceftazidime (3rd gen), Cefoperazone (3rd gen) and Cefepime (4th gen)
Erythromycin increases ORAL bioavailability of…
digoxin
What does gent not have action against
anaerobes
Anti MRSA
vanc
clinda
linezolid
Anaerobes acting antibiotics
meropenem
clindamycin
metronidazole
Plus pen G just not beta lactamase ones
Drugs with no gram -ve cover
flucloxacillin
1st gen cephalosporin
vanc
clinda
linezolid
metronidazole
Bioavailability erythromycin
0.35
PK amphoteracin B
Poor F
PB 90%
2-3% crosses BBB
T1/2 15d
Medication for hydatid disease
Albendazole
Doxycycline pk
A f1, inhibited by aluminium and antacids
40-80pb
Not in csf
Excreted in stool
Anti pseudomonal agents
CMAC
Cephalosporins (x3)
Meropenem
Aminoglycosides
Ciprofloxacin
Gentamicin protein binding
10%
T1/2 2-3h
Abx with ESBL coverage
MEGA C
Meropenem
Ertapenem
Gentamicin (50%)
Amikacin
Ciprofloxacin