DRUGS OF CHOICE ACCORDING TO INFECTING ORGANISM 1,2

DRUGS OF CHOICE ACCORDING TO INFECTING ORGANISM^1,2

ORGANISM	FIRST CHOICE	ALTERNATIVES
Gram-Positive Cocci
*Staphylococcus aureus (see 1III.C) Methicillin resistant (MRSA)	antistaphylococcal penicillin or first generation cephalosporin vancomycin with or without rifampin linezolid (zyvox)	amox/clav^a or ampi/sulbac clindamycin vancomycin TMP/SMX^b (some resistant) and/or rifampin
Staphylococcus epidermidis (coag. neg.)	vancomycin with or without rifampin	antistaph. penicillin or cephalosporin if sensitive (75 percent are resistant)
Streptococcus pyogenes and Streptococcus Groups B, C, G, F, S. viridans	penicillin or amoxicillin or 1st/2nd gen. cephalosporin (add gentamicin for serious infection)	amox/clav^a or ampi/sulbac clindamycin or vancomycin erythro-clarithro-azithro^c
*Streptococcus Group D (Enterococcus)	ampicillin or penicillin G with gentamicin^e	vancomycin with gentamicin^e amox/clav^a or ampi/sulbac
*Streptococcus pneumoniae (pneumococcus)	see 1III.A
Streptococcus anaerobic (peptostreptococcus)	clindamycin	amox/clav^a or ampi/sulbac penicillin plus metronidazole vancomycin
Gram-Negative Cocci
Moraxella catarrhalis (Branhamella catarrhalis)	see
*Neisseria gonorrhoeae (see)	ceftriaxone or cefixime or cefpodoxime	any quinolone^g
Neisseria meningitidis	penicillin G	ceftriaxone, cefotaxime, cefuroxime TMP-SMX^b chloramphenicol
Gram-Positive Bacilli
*Actinomyces israeli	penicillin or aminopenicillin	doxycycline, ceftriaxone clindamycin
Bacillus anthracis	ciprofloxacin or doxycycline	penicillin or erythromycin
Clostridium difficile	metronidazole or vancomycin	bacitracin
Clostridium perfringens	penicillin plus clindamycin	doxycycline cefoxitin chloramphenicol
Clostridium tetani	penicillin with metronidazole	doxycycline imipenem
Corynebacterium diphtheriae	erythromycin or clindamycin	rifampin, penicillin
Listeria monocytogenes	ampicillin with or without gentamicin^e	TMP-SMX^b
*Nocardia	TMP-SMX^b	minocycline amikacin plus ceftriaxone
Enteric Gram-Negative Bacilli
*Bacteroides, intestinal and oropharyngeal anaerobes, see	clindamycin	amox/clav^a or ampi/sulbac metronidazole cefoxitin or cefotetan imipenem or meropenem
*Enterobacter	imipenem or meropenem OR piperacillin plus gentamicin^e	gentamicin, etc.^e ticar/clav or pipr/tax^d
*Proteus mirabilis	ampicillin or TMP/SMX	most agents
E. coli Klebsiella pneumoniae Other Proteus Providencia *Serratia	cefotaxime or ceftizoxime or ceftriaxone or cetazidime	ampicillin with gentamicin^e aztreonam ticar/clav, pipr/taz^d ciprofloxacin et al. quinolones^g TMP-SMX^b
Other Gram-Negative Bacilli
Acinetobacter	imipenem or meropenem OR amikacin with quinolone^g	amikacin plus ceftazidime amox/clav or ampi-sulbac^a
Bordetella pertussis (Whooping cough)	erythromycin or clarithromycin	TMP-SMX^b
*Brucella	doxycycline with gentamicin^e, streptomycin, or rifampin	quinolone^g plus rifampin plus gentamicin TMP/SMX^b plus gentamicin
Eikenella corrodens	amipicillin or amox/clav^a or ampi/sulbac	TMP/SMX, quinolone^g, doxycycline, cefotaxime
F. tularensis	streptomycin or gentamicin^e	doxycycline or chloramphenicol ciprofloxacin, rifampin
*Hemophilus influenzae Meningitis/epiglottitis	ceftriaxone or cefotaxime	trovafloxacin, meropenem ampicillin/sulbactam
*Hemophilus influenzae Otitis, sinusitis, etc. See	Amox/clav^a or ampi/sulbac erythromycin with sulfonamide	TMP-SMX^b ampicillin/amoxicillin clarithromycin or azithromycin 2nd/3rd gen. cephalosporins quinolones^g
Legionella pneumophila	erythromycin (with or without rifampin) or quinolones^g	azithromycin or clarithromycin TMP-SMX^b, doxycycline
*Pseudomonas aeruginosa)	gentamicin^eticarcillin or piperacillin orally: ciprofloxacin or ofloxacin	ceftazidime, cefepime, ticar/clav^d imipenem or aztreonam plus gentamicin^e or rifampin
Miscellaneous Organisims
Bartonella (formerly Rochalimaea) (cat scratch)	doxycycline or erythromycin or clarithromycin or azithromycin	ciprofloxacin TMP-SMX^b
Chlamydia species	erythro-clarithro-azithro^c	doxycycline, quinolones^g
Mycoplasma pneumoniae	erythro-clarithro-azithro^c	doxycycline quinolones^g
Rickettsia	doxycycline	chloramphenicol quinolones^g
Spirochetes Borrelia burgdorferi (Lyme). Treponema pallidum (syphilis) T. pertenue (yaws)	ceftriaxone or cefuroxime or doxycycline or amoxicillin penicillin penicillin	cefotaxime erythro-clarithro-azithro^c doxycycline ceftriaxone tetracycline
Fungi: Systemic and topicals, etc., information)
Aspergillus species	amphotericin B	itraconazole
Blastomyces dermatitidis	amphotericin B or itraconazole	fluconazole
Candida species	fluconazole	amphotericin B
Chromomycosis	itraconazole
Coccidioides immitis	itraconazole	fluconazole amphotericin B
Cryptococcus neoformans	amphotericin B	fluconazole
Histoplasma capsulatum	amphotericin B	itraconazole
Mucor species	amphotericin B	none
Paracoccidioides brasiliensis	itraconazole or ketoconazole	amphotericin B sulfonamide
Pseudallescheria boydii	itraconazole	miconazole
Sporothrix schenckii	cutaneous: potassium iodide systemic: itraconazole	amphotericin B

Medical Letter Handbook of Antimicrobial Therapy, current edition
Gilbert, et al.: The Sanford Guide to Antimicrobial Therapy 2000, page 71 ff.

^*Because drug resistance may be a problem, sensitivity studies are indicated. ^aAmox/clav: amoxicillin/potassium clavulanate (Augmentin). Ampi-sulbac: ampicillin/sulbactam (Unasyn).

^bTMP-SMX: trimethoprim-sulfamethoxazole (Bactrim, etc.)

^cErythro-clarithro-azithro: erythromycin or clarithromycin (Biaxin) or azithromycin (Zithromax).

^dTicar/clav: ticarcillin/potassium clavulanate. Pipr/taz: piperacillin/tazobactam (Zosyn)

^eGentamicin or tobramycin or amikacin.

^fWhen history of anaphylaxis from penicillins.
^gfluroquinolones: ciprofloxacin (Cipro), gatifloxacin (Tequin), gemifloxacin (Factive), moxifloxacin (Avelox)