Antimicrobials Flashcards
Antibiotics:
Penicillins:
class
main types and their characteristics
Beta Lactams
Penicillin
– Mainly active against streptococci
Amoxicillin
– Also some activity against Gram-negatives
Flucloxacillin
– Active against staphylococci & streptococci
Β-lactamase inhibitor combinations
– Co-amoxiclav (all of above +anaerobes + ↑Gneg
– Piperacillin/tazobactam (asabove+↑↑Gnegincl
pseudomonas)
Antibiotics: Cephalosporins: class main action example and characteristics concerns
beta lactams
↑broad-spectrum but no anaerobe activity
Cetriaxone has good activity in the CSF
Concern over association with C. difficile
Antibiotics:
Carbapenems:
class
example and characteristics
beta lactams
Meropenem (and imipenem)
– Very broad spectrum (incl anaerobes)
– Active against most (not all) Gram negs
– Generally safe in penicillin allergy, other
than anaphylaxis
Antibiotics:
Name the 4 main types of beta lactams from roughly less to more broad spectrum
Penicillins
Cephalosporins
Carbapenems
Monobactams
Antibiotics:
name some types of Glycopeptides and their characteristics
Vancomycin
– Active against most Gram pos (not Gnegs)
– Some enterococci resistant (VRE)
– Resistance in staphs rare
– Not absorbed (oral for C. difficile only)
– Therapeutic drug monitoring (TDM) required (narrow
therapeutic window)
• Teicoplanin
– Similar activity to vancomycin
– Easier to administer
Antibiotics:
Name some tetracyclines and their main characteristics
Tetracycline & doxycycline
– Similar spectrum, both oral only
– Broad-spectrum but specific use in penicillin
allergy, usually for Gram pos
– Active in atypical pathogens in pneumonia
– Active against chlamydia & some protozoa
– Shouldn’t be given to children
Antibiotics:
name an aminoglycoside and its characteristics
Most common agent is gentamicin • Profound activity against Gram negs • Good activity in the blood/urine • Potentially nephrotoxic/ototoxic • Therapeutic drug monitoring (TDM) required (narrow therapeutic window) • Generally reserved for severe Gram neg sepsis
Antibiotics:
name some Macrolides and its characteristics
erythromycin (& clarithromycin)
• Well distributed including intracelleluar
penetration
• Alternative to penicillin for mild Gram
pos infections
• Also active against atypical respiratory
pathogens
Antibiotics:
name a Quinolone and its characteristics
Commonest example ciprofloxacin
• Inhibit DNA gyrase
• Very active against Gram negs
• Also active against atypical pathogens
• Increasing resistance and risk of C. difficile
Antibiotics:
name some inhibitors of folic acid synthesis (nucleic acid synthesis) and their characteristics
Trimethoprim and sulphonamides: • Trimethoprim used alone in the UK for UTI • When combined with sulphamethoxazole – Co-trimoxazole – Used to treat PCP – Has activity against MRSA
name 2 types of antifungals
azoles: active against yeasts +/- molds
polyenes
name some azoles (antifungal) and their characteristics
Inhibit cell-membrane synthesis
– Fluconazole used to treat Candida
- Itra/vori/posaconazole also active against Aspergillus (more complex fungal infections)
name some polyenes (antifungal) and their characteristics
Inhibit cell membrane function
– Nystatin for topical treatment of candida
– Amphotericin for IV treatment of systemic fungal
infections (e.g. aspergillus)
name some antivirals and their characteristics
Aciclovir
– When phosphorylated inhibits viral DNA
polymerase
– Herpes simplex – genital herpes, encephalitis
– Varicella zoster – chicken pox & shingles
• Oseltamivir (‘Tamiflu’)
– Inhibits viral neuraminidase
– Influenza A & B
name a combined antibacterial and antiprotozal agent and it’s uses
Metronidazole: • Active against anaerobic bacteria • Also active against protozoa: – Amoebae (dysentery & systemic) – Giardia (diarrhoea) – Trichomonas (vaginitis) used more in tropical climates
