IT IS ADMINISTERED BY DEEP I.M. INJECTION. FOR EARLY SYPHILIS :- 1.8 GM BY DEEP I.M. INJ. USUALLY AS 2 INJECTIONS AT SEPARATE SITES. IN LATE SYPHILIS :- 1.8 GM AT WEEKLY INTERVALS FOR 3 CONSECUTIVE WEEKS. CHILDREN OVER 2 YEARS OF AGE :- 37.5 MG/KG/BODY WT. FOR THE TREATMENT OF OTHER TREPONEMAL INFECTIONS SUCH AS YAWS, PINTA, AND ENDEMIC SYPHILIS, STREPTOCOCCAL PHARYNGITIS AND THE PRIMARY PREVENTION OF RHEUMATIC FEVER, AND ACUTE RHEUMATIC FEVER :- 900 MG FOR ADULTS AND 450 MG FOR CHILDREN AS SINGLE INJECTION.