IV/IM Adult 1-2 g once a day or bid, should not exceed 4 g daily. 
Uncomplicated gonococcal infection 250 mg IM as single dose. 
Surgical infection prophylaxis 1 g IV 0.5-2 hr pre-op. 
Childn Skin & skin structure infections 50-70 mg/kg once a day or bid, should not exceed 2 g. Acute bacterial otitis media 50 mg/kg IM as single dose (not to exceed 1g). 
Serious miscellaneous infections (except meningitis) 50-75 mg/kg daily in 2 divided doses every 12 hr, should not exceed 2 g. 
Meningitis Initially 100 mg/kg (not to exceed 4 g), total daily dose 100 mg/kg/day (not to exceed 4 g daily). Dose may be administered once a day or in equally divided doses every 12 hr. Duration of therapy: 7-14 days. 
Prevention of secondary cases of meningococcal meningitis 250 mg as single IM in adult & 125 mg in childn. Duration of therapy: 4-14 days in complicated infections; at least 10 days for infections caused by 
Strep pyogenes.