Benzylpenicillin sodium

Intrapartum GBS prophylaxis when indicated, distinct from treatment of maternal sepsis

Slow IV injection or infusion

Load once, then every 4 hours until delivery

Intrapartum only; do not delay an indicated birth to complete four hours of antibiotics · For the cited 1.2 g vial, dissolve each vial in at least 8 mL water for injections/0.9% saline for IV injection (powder displacement ~0.8 mL), or at least 20 mL for infusion. Account for final concentration when withdrawing partial vials. Give doses >1.2 g at least 1 minute per 300 mg: 3 g ≥10 min; 1.5 g ≥5 min

• Do not confuse grams, milligrams and million units; ampicillin is a different regimen with 2 g loading then 1 g every 4 h.

3 g loading then 1.5 g every 4 hours; stop at birth. Do not confuse grams with million units.

Adult neurosyphilis, ocular or otosyphilis with specialist evaluation

Slow IV injection/infusion

Every 4 hours

10–14 days; additional stage-dependent benzathine treatment may be considered after completion · For the cited 1.2 g (2-million-unit) sodium vials, use two vials per 2.4 g dose. Dissolve each in at least 8 mL water for injections/0.9% saline and give the complete dose slowly over at least 8 minutes (label: ≥1 minute per 300 mg). For infusion, reconstitute each vial in at least 20 mL compatible fluid. Verify the local product and account for sodium/fluid load

• Dose from CDC; preparation from the registered benzylpenicillin sodium SmPC. Potassium and sodium formulations have different electrolyte loads.

24 million units/day in this selected schedule; reduce/adjust for significant renal impairment