0.6 TO 2.4 GM DAILY IN 2 TO 4 DIVIDED DOSES BY I.M. OR SLOW I.V. INJECTION. BUT HIGHER DOSES GIVEN I.V. , OFTEN BY INFUSION OR SEVERE INJECTION LIKE STREPTOCOCCAL ENDOCARDITIS :- 7.2 (1.2 GM EVERY 4 HOURS) DAILY. CHILDREN 1 MONTH TO 12 YEARS OF AGE :-100 MG/KG DAILY IN 4 DIVIDED DOSES. INFANTS 1-4 WEEKS OF AGE :- 75 MG/KG DAILY IN 3 DIVIDED DOSES. MENINGOCOCCAL INFECTION :- 600 MG TO 1.2 GM DAILY, CHILDREN BELOW 1 YEAR 300 MG I.V. OR I.M. ORAL TREATMENT :-125 TO 312 MG 3 OR 4 TIMES DAILY BEFORE MEALS.