Antibiotics for year 3 medics.pdf

(2) RELIABLE ANTIBIOTIC SENSITIVITIES OF ORGANISMS
ORGANISM
ANTIBIOTIC
NOTE
Strep pyogenes (‘group A strep’) erythromycin active but does NOTcross the blood-brain barrier sepsis usually with a cephalosporin– see later Oral anaerobes often sensitive topenicillin as well drugs in UK: may needstreptomycin, ciprofloxacin etc (3) IMPORTANT ANTIBIOTIC TREATMENTS – General medical infections
INFECTION
ANTIBIOTICS
Classically penicillin (Alternatives:
cefotaxime or ceftriaxone very often used
not cross BBB! Chloramphenicol
Haemophilus : Cephalosporins as above
Rifampicin or ciprofloxacin or
ceftriaxone for prophylaxis of close
contacts
Piperacillin/tazobactam (‘TAZOCIN’), or
resistant Klebsiella, Enterobacterin hospitals Gent enhances killing Add gentamicin if severe:once daily dose
Penicillin (or amoxicillin) &
clarithromycin [clarithro is similar to
Cephalosporin (e.g. cefuroxime) +
Gent enhances killing of organisms metronidazole
Add gentamicin if severe:once daily dose
Penicillin/Amoxycillin or Ciprofloxacin,
cephalosporins). Tetracyclines for
Chlamydia infection. Penicillin for
syphilis
Trimethoprim, co-amoxiclav
("Augmentin"), oral cephalosporins (e.g.
shows E. coli is sensitive (50%).
cefadroxil); as for septicaemia if severe Penicillin or amoxycillin; erythromycin
Many sore throats are viral. Butpenicllin may be given because of and glomerulonephritiscomplications after GAS Hospital – Clostridium difficile INFECTION
ANTIBIOTICS
Isoniazid + Rifampicin + Ethambutol +/-
Pyrazinamide NB use all four if drug
resistance cannot be ruled out
MAI complex: Clarithromycin,rifabutin, ciprofloxacin Penicillin, tetracycline
e.g. Syphilis, Borrelia (Lymedisease), Leptospira Tetracyclines, erythromycin [or clarithro]
Falciparum: Quinine + Fansidar
Other species: Chloroquine
Invasive: Amphotericin B
(topical) & fluconazole (oral/IV).
Note on some of antibiotics:
⇒ AMOXICILLIN and AMPICILLIN are more or less the same but these days
most people use AMOX because it can be given three times a day (not four)
and is better absorbed. Amoxicillin is often (wrongly) spelt amoxycillin, it is
the same.
⇒ CO-AMOXICLAV (‘Augmentin’) is souped-up amoxicillin, i.e. amox plus
clavulanic acid. The latter blocks the enzyme beta-lactamase that is
produced by some bacteria e.g. Staph aureus, E. coli, Bacteriodes (an
anaerobe present in the colon)
⇒ CLARITHROMYCIN is a new version of ERYTHROMYCIN. It is better tolerated
(fewer GI symptoms) so is commonly used. Otherwise it is similar in activity.
⇒ When we talk about ‘MRSA’ it stands for ‘methicillin-resistant
Staphylococcus aureus’. Methicillin is an old version of flucloxacillin so
really it means flucloxacillin-resistant Staph aureus. However the important
point is that these staphs are resistant to many other agents including
gentamicin, erythromycin etc. Vancomycin is reliable but recently (USA,
June 2002) totally resistant vancomycin resistant strains have been
reported.
⇒ Note that a lot of Vancomycin is also used for Coagulase-negative staph
infections (e.g. Staph epidermidis) as these are common in lines, prosthetic
implants etc., especially in high-dependency patients.
Colour relates to Gram stain…if that helps… ANTIBIOTIC
Staph
MRSA
Strepto-
Entero-
GC &
Coli-
Haemo
Pseudo
Anaer-
Spiro-
Chlamydia,
TB
aureus
& CNS
cocci
coccus
Meningo
forms
-philus
-monas
obes
chaetes
mycoplasma,
rickettsias
cefadroxilInjectablecephalosporins:Cefuroxime (4) = poor activity, resistance common or not appropriate for therapy

Source: http://www.fhs.d211.org/departments/science/dsanchez/Course%20Folders/Bio%20II/ANTIBIOTICSFORYEAR3MEDICS.pdf