Table 164-3.

USEFUL ANTIBIOTICS FOR TREATMENT OF PYOTHORAX

Antibiotic	Trade Name	Dosage	Indications
Penicillin G	generic	20,000–40,000 U/kg q6–8h IV IM	anaerobes,*Pasteurella, Actinomyces
Ampicillin	Omnipen	20 mg/kg q6–8h IV IM SC	anaerobes,*Pasteurella and some other gram negatives
Amoxicillin	Amoxi-Tabs	20 mg/kg q8–12h PO	anaerobes,*Pasteurella and some other gram negatives
Amoxicillin/clavulanate	Clavamox	20 mg/kg q12h PO	anaerobes,†Pasteurella and many other gram negatives
Chloramphenicol	Chloromycetin	50 mg total/cat q12h IV SC PO	anaerobes,† gram-positive and gram-negative aerobes
Clindamycin	Antirobe	10 mg/kg q12h PO	anaerobes†
Metronidazole	Flagyl	10–15 mg/kg q8–12h PO IV	anaerobes†
Enrofloxacin§¶	Baytril	Dogs: 5 mg/kg q12h PO, IV, SC;	most gram-negative and gram-positive aerobes
		Cats: 5 mg/kg q24h PO, IV, SC
Trimethoprim-sulfadiazine	Tribrissen	15 mg/kg q12h PO	Nocardia
Amikacin‡	Amiglyde-V	10 mg/kg q8–12h IV IM SC	gram negatives§
Cefoxitin	Mefoxin	20–30 mg/kg q8h IV IM	anaerobes,† gram-negatives
Ticarcillin	Ticar	30–50 mg/kg q6h IV IM	anaerobes,† gram-negatives, Pseudomonas

^*Excluding Bacteroides fragilis.

^†Including most penicillin-resistant strains of Bacteroides fragilis.

^‡Caution: uncorrected dehydration may potentiate aminoglycoside nephrotoxicity.

^§Enrofloxacin and aminoglycosides are ineffective against anaerobes; thus, always use in combination with penicillin or other antibiotic with activity against anaerobes when treating pyothorax.

^¶Doses exceeding 5 mg/kg daily are retinotoxic in cats and may cause blindness.