Chloramphenicol

General

• Type: bacteriostatic antibiotic
• Dosage Forms: IV, IM, eye drops
• Common Trade Names: pentamycetin, chloromycetin

Adult Dosing

Infection, General

• 50-100mg/kg/day IV divided q6h

Bacterial meningitis

• 4 g/day IV divided q6h
• Alt: 75-100mg/kg/day IV divided qgh

Bacterial conjunctivitis

• 0.5% ophthalmic solution 1 drop QID for 7 days

Indications by Disease

Disease	Dose	Context
Bacterial conjunctivitis	0.5% ophthalmic solution 1 drop QID for 7 days	Bacterial Conjunctivitis, Topical
Plague	25mg/kg PO q6hrs	Postexposure prophylaxis age over 2 only
Rocky mountain spotted fever	50-100mg/kg/day div q6hrs (max 4g/day)	Preferred in pregnancy
Tularemia	15mg/kg IV q6hrs x 14 days	Active disease

Pediatric Dosing

Bacterial meningitis

• 75-100mg/kg/day IV divided q6h; Max 4g/day

Indications by Disease

Disease	Dose	Context
Plague	25mg/kg PO/IV q6hrs (max 4g/day); age >2 only	Pediatric Prophylaxis
Rocky mountain spotted fever	50-100mg/kg/day IV divided q6hrs (max 4g/day)	Pediatric Doxycycline Allergy

Special Populations

• Pregnancy: Category C (risk not ruled out)
• Lactation: passes into breast milk and should be avoided if possible
• Renal Dosing: minimally excreted via kidneys
  • Adult: amount not defined
  • Pediatric: amount not defined
• Hepatic Dosing: metabolized by the liver, therefore dose must be reduced
  • Adult: amount not defined
  • Pediatric: amount not defined

Contraindications

• Allergy to class/drug

Adverse Reactions

Serious

• aplastic anemia
• agranulocytosis
• thrombocytopenia
• anaphylaxis
• gray baby syndrome
• pseudomembranous colitis

Common

• headache
• nausea, vomiting
• diarrhea
• fever
• rash
• urticaria
• peripheral neuropathy
• blurred vision

Pharmacology

• Half-life: 1.5 - 4.1 hours
• Metabolism: Liver
• Excretion: Urine
• Mechanism of Action: binds to 50S ribosomal subunit inhibiting protein synthesis

Antibiotic Sensitivities

Group	Organism	Sensitivity
Gram Positive	Strep. Group A, B, C, G	S
	Strep. Pneumoniae	S
	Viridans strep	X1
	Strep. anginosus gp	X1
	Enterococcus faecalis	I
	Enterococcus faecium	I
	MSSA	I
	MRSA	R
	CA-MRSA	X1
	Staph. Epidermidis	R
	C. jeikeium	R
	L. monocytogenes	S
Gram Negatives	N. gonorrhoeae	S
	N. meningitidis	S
	Moraxella catarrhalis	S
	H. influenzae	S
	E. coli	S
	Klebsiella sp	I
	E. coli/Klebsiella ESBL+	I
	E coli/Klebsiella KPC+	R
	Enterobacter sp, AmpC neg	R
	Enterobacter sp, AmpC pos	R
	Serratia sp	X1
	Serratia marcescens	R
	Salmonella sp	S
	Shigella sp	S
	Proteus mirabilis	X1
	Proteus vulgaris	I
	Providencia sp.	X1
	Morganella sp.	X1
	Citrobacter freundii	X1
	Citrobacter diversus	X1
	Citrobacter sp.	X1
	Aeromonas sp	X1
	Acinetobacter sp.	R
	Pseudomonas aeruginosa	R
	Burkholderia cepacia	S
	Stenotrophomonas maltophilia	S
	Yersinia enterocolitica	S
	Francisella tularensis	S
	Brucella sp.	S
	Legionella sp.	X1
	Pasteurella multocida	X1
	Haemophilus ducreyi	X2
	Vibrio vulnificus	X2
Misc	Chlamydophila sp	S
	Mycoplasm pneumoniae	S
	Rickettsia sp	S
	Mycobacterium avium	X1
Anaerobes	Actinomyces	X2
	Bacteroides fragilis	X2
	Prevotella melaninogenica	S
	Clostridium difficile	I
	Clostridium (not difficile)	S
	Fusobacterium necrophorum	S
	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

See Also

• Antibiotics (Main)