600 to 3,600 mg (1 to 6 mega units) daily, divided into 4 to 6 doses, depending on the indication. Higher doses (up to 14.4 g/day (24 mega units) in divided doses) may be given in serious infections such as adult meningitis by the intravenous route.
In bacterial endocarditis, 7.2 to 12 g (12 to 20 mega units) or more may be given daily in divided doses by the intravenous route, often by infusion.
High doses should be administered by intravenous injection or infusion, with intravenous doses in excess of 1.2 g (2 mega units) being given slowly, taking at least one minute for each 300 mg (0.5 mega unit) to avoid high levels causing irritation of the central nervous system and/or electrolyte imbalance.
High dosage of Benzylpenicillin sodium BP may result in hypernatraemia and hypokalaemia unless the sodium content is taken into account.
Children aged 1 month to 12 years:
100 mg/kg/day in 4 divided doses; not exceeding 4 g/day.
Infants 1-4 weeks:
75 mg/kg/day in 3 divided doses.
50 mg/kg/day in 2 divided doses.
Children 1 month to 12 years: 180-300 mg/kg/day in 4-6 divided doses, not exceeding 12 g/day.
Infants 1-4 weeks: 150 mg/kg/day in 3 divided doses.
Newborn infants: 100 mg/kg/day in 2 divided doses.
Adults and children over 12 years: 2.4 g every 4 hours.
Premature babies and neonates:
Dosing should not be more frequent than every 8 or 12 hours in this age group, since renal clearance is reduced at this age and the mean half-life of Benzylpenicillin may be as long as 3 hours.
Since infants have been found to develop severe local reactions to intramuscular injections, intravenous treatment should preferably be used.
Patients with renal insufficiency:
For doses of 0.6-1.2 g (1-2 mega units) the dosing interval should be no more frequent than every 8-10 hours.
For high doses e.g. 14.4 g (24 mega units) required for the treatment of serious infections such as meningitis, the dosage and dose interval of Benzylpenicillin sodium BP should be adjusted in accordance with the following schedule: (See Table 4.)
Click on icon to see table/diagram/image
The dose in the previous table should be further reduced to 300 mg (0.5 mega units) 8 hourly if advanced liver disease is associated with severe renal failure.
If haemodialysis is required, an additional dose of 300 mg (0.5 mega units) should be given 6 hourly during the procedure.
Elimination may be delayed in elderly patients and dose reduction may be necessary.
Route of administration:
Benzylpenicillin may be given by intramuscular or intravenous injection. The intravenous route is preferred in cases of shock as blood levels following intramuscular injection are unreliable in shocked patients.
Preparation of solution: Pharmaceutical preparation:
BEPEN Injection should be reconstituted with Water for Injections BP. To achieve a particular concentration, Water for Injections BP should be added to the vial according to the table as follows. (See Table 5.)
Click on icon to see table/diagram/image
When BEPEN is reconstituted with Water for Injections, it must be used immediately to reduce microbiological hazard. BEPEN is for one dose in one patient only. Discard any remaining contents.
600 mg vial: Dissolve 600 mg (1 mega unit) in 1.6 to 2.0 mL of Water for Injections BP.
3 g vial: Dissolve 3 g (5 mega unit) in 8.0 to 10.0 mL of Water for Injections BP as indicated in the previously mentioned Table 5 to give 300 mg/mL.
Intravenous administration may be by intermittent injections or by injection into an infusion line. It should not be added to an intravenous infusion bottle as benzylpenicillin is unstable at room temperature and may form highly allergenic derivatives.
Reconstitute and dilute each 600 mg of BEPEN in a sufficient volume of Water for Injection to achieve a final concentration of 600 mg per 10 mL. This quantitative ratio produces an approximately isotonic solution with the recommended osmolarity for I.V. injection/infusion.
Sodium overload and/or heart failure may occur if benzylpenicillin sodium is administered in sodium-containing solvents to patients who suffer from renal failure and/or heart failure. Therefore, for such patients, benzylpenicillin sodium should not be reconstituted in sodium-containing liquids such as Sodium Chloride Injection BP or Ringer's solution due to their additional electrolytic content.