Syphilis Early syphilis: 1.8 g deep IM given as 2 inj at separate sites. Late syphilis: 1.8 g for 3 consecutive wk as wkly intervals.
Congenital syphilis Infant <2 yr Single IM dose of 37.5 mg/kg.
Yaws, bejel & pinta 1.2 MU (1 inj).
Prophylaxis of rheumatic fever & glomerulonephritis Adult & childn 1.2 MU IM every 4 wk.