Cloxacillin

General

• Type: Beta lactamase resistant penicillins
• Dosage Forms: 125mg/5 ml oral powder, 250mg, 500mg
• Common Trade Names: Cloxapen, Dry Clox, Tegopen

Adult Dosing

Upper Respiratory Tract Infection

• 250mg PO q6hrs for 7-14 days

Pneumonia

• 500mg PO q6hrs for up to 21 days

Soft tissue/skin infection

• 500mg PO q6hrs for 7 days or until 3 days after acute inflammation resolves

Pediatric Dosing

Upper Respiratory Tract Infection

• >=1 yr to 18 yrs: 50-100mg/kg/day orally divided every 6 hrs, Max dose 4g/day

Soft tissue and skin infection

• >=1 yr to 18 yrs: 50-100mg/kg/day orally divided every 6 hrs, Max dose 4g/day

Special Populations

• Pregnancy Rating: Pregnancy Category B
• Lactation: acceptable to use during breastfeeding
• Renal Dosing: no adjustments needed
• Hepatic Dosing: no adjustments needed

Contraindications

• Allergy to class/drug

Adverse Reactions

Serious

• allergic reaction
• seizures
• pseudomembranous colitis
• neutropenia
• leukopenia
• thrombocytopenia
• cholestatic hepatitis
• hypersensitivity reaction

Common

• nausea, vomiting
• diarrhea, abdominal pain
• thrush/yeast infection

Pharmacology

• Half-life: 30 min - 1 hr
• Metabolism: partially metabolized
• Excretion: renal and biliary
• Mechanism of Action: bactericidal; adheres to penicillin-binding proteins inhibiting bacterial cell wall synthesis

Antibiotic Sensitivities

Group	Organism	Sensitivity
Gram Positive	Strep. Group A, B, C, G	S
	Strep. Pneumoniae	S
	Viridans strep	I
	Strep. anginosus gp	S
	Enterococcus faecalis	R
	Enterococcus faecium	R
	MSSA	S
	MRSA	R
	CA-MRSA	R
	Staph. Epidermidis	S
	C. jeikeium	R
	L. monocytogenes	R
Gram Negatives	N. gonorrhoeae	R
	N. meningitidis	R
	Moraxella catarrhalis	R
	H. influenzae	R
	E. coli	R
	Klebsiella sp	R
	E. coli/Klebsiella ESBL+	R
	E coli/Klebsiella KPC+	R
	Enterobacter sp, AmpC neg	R
	Enterobacter sp, AmpC pos	R
	Serratia sp	R
	Serratia marcescens	X1
	Salmonella sp	R
	Shigella sp	R
	Proteus mirabilis	R
	Proteus vulgaris	R
	Providencia sp.	R
	Morganella sp.	R
	Citrobacter freundii	R
	Citrobacter diversus	R
	Citrobacter sp.	R
	Aeromonas sp	R
	Acinetobacter sp.	R
	Pseudomonas aeruginosa	R
	Burkholderia cepacia	R
	Stenotrophomonas maltophilia	R
	Yersinia enterocolitica	R
	Francisella tularensis	X1
	Brucella sp.	X1
	Legionella sp.	R
	Pasteurella multocida	R
	Haemophilus ducreyi	X1
	Vibrio vulnificus	X1
Misc	Chlamydophila sp	R
	Mycoplasm pneumoniae	R
	Rickettsia sp	X1
	Mycobacterium avium	X1
Anaerobes	Actinomyces	R
	Bacteroides fragilis	R
	Prevotella melaninogenica	R
	Clostridium difficile	X1
	Clostridium (not difficile)	X1
	Fusobacterium necrophorum	X1
	Peptostreptococcus sp.	S

Key

• S susceptible/sensitive (usually)
• I intermediate (variably susceptible/resistant)
• R resistant (or not effective clinically)
• S+ synergistic with cell wall antibiotics
• U sensitive for UTI only (non systemic infection)
• X1 no data
• X2 active in vitro, but not used clinically
• X3 active in vitro, but not clinically effective for Group A strep pharyngitis or infections due to E. faecalis
• X4 active in vitro, but not clinically effective for strep pneumonia

Source

Authors

Ross Donaldson, Jung-Eun Lim, Neil Young, Daniel Ostermayer