Antibiotic Class:


Antimicrobial Spectrum:

Streptococcus spp., Staphylococcus spp., H. influenzae, M. catarrhalis, Bacteroides spp., (Clostridia spp.of variable susceptibility) Prevotella spp., Fusobacterium spp., Veillonella spp., Chlamydia trachomatis

Mechanism of Action:

Binds to the 50S ribosomal subunit of rRNA and inhibits the initiation of peptide chain synthesis


Time-dependent killing


Cmax (900mg IV): 15.1mcg/ml; Half-life: Approximately 3 hours; Figure 2, 3

Adverse Effects:

GI: diarrhea, C. difficile associated diarrhea

Skin: rash, anaphylaxis, Stevens-Johnson syndrome

Cardiovascular: hypotension

GU: cervicitis, vaginitis


Capsule: 150 mg, 300 mg
Cream, vaginal, as phosphate: 2% (40 g)

Foam, topical, as phosphate 1%: (50 g, 100 g)

Gel, topical 1%: (30 g, 60 g, or 40ml, 75ml)
Granules for oral solution: 75 mg/5 mL (100 mL)

IV: 300 mg (50 mL), 600 mg (50 mL), 900 mg (50 mL)

Lotion 1%: 60 mL

Pledgets, topical 1%: #60
Solution, topical 1%: (30 mL, 60 mL)

Vaginal Suppository: 100 mg #3

Adults: 300mg PO q 6 hours; IV: 600mg to 1200mg/day divided q 12 6 hours (1200 to 2700mg/day divided for serious infections); topical: apply to affected area q 12 hours; Intra-vaginal cream: One applicatorful hs for 3 or 7 days (vaginal suppository for 3 days).

Children > 10kg: 8-25mg/kg/day PO divided q 8 6 hours (palmitate salt suspension)

Children < 10kg: 37.5mg PO q 8 hours

Children > 1 month: 20 40mg/kg/day IV divided q 8 6 hours

Children > 12 years old (topical foam): apply once daily to affected areas

Neonates < 1 month: 15 20mg/kg/day IV divided q 8 6 hours

Disease state based dosing:

Renal failure:  Dosing adjustments not necessary

Hepatic failure:  Dosing adjustments not necessary

Dosing during Continuous Renal Replacement Therapy

CVVH (Continuous venovenous hemofiltration): 600-900mg q8h

CVVHD (Continuous venovenous hemodialysis): 600-900mg q8h

CVVHDF (Continuous venovenous hemodiafiltration) 600-900mg q8h

Note: CVVH is mainly for fluid removal alone. Many institutions will employ more CVVHD or CVVHDF which combine dialysis with fluid removal.



Drug Interactions:

Erythromycin (macrolides): In-vitro antagonism clinical significance unknown

Skeletal muscle relaxants (atracurium, vecuronium, pancuronium, cyclobenzaprine, and others): enhanced neuromuscular blockade.


Category C: Risk unknown. Human studies inadequate.

Monitoring Requirements:

Therapeutic: Culture and sensitivities, signs and symptoms of infection

Toxic:  In severe renal or hepatic failure, serum concentration monitoring is recommended.

Brand names/Manufacturer:

Various manufacturers (click here for list)