Ureido penicillins

Penicillin - Synthesis and Drug Profile

Ureido penicillins

i. Aziocillin (Azlin)

Synthesis

Properties and uses: It is the newest of ureidopenicillins, and is about 10 times more active than carbenicillin against Pseudomonas and Streptococci.

Dose: The dose is 8–18 g per day in 4–6 divided doses.

ii. Piperacillin (Pipracil, Pracil)

Synthesis

Properties and uses: Piperacillin sodium is a white hygroscopic powder, soluble in water and methanol, practically insoluble in ethyl acetate. It is available as a powder for solubilization and injection. It is best given in combination with an aminoglycoside antibiotic.

Assay: It is assayed by adopting liquid chromatography technique.

Dose: For serious and complicated infections: The adult dose as sodium is 200–300 mg/kg daily in divided doses or 3–4 g per day in divided doses of every 4 or 6 h. For life threatening conditions: especially those caused by Pseudomonas or Klebsiella spp, the dose is at least 16 g per day; usual maximum dose is 24 g per day. For children: 1 month–12 years, as sodium 100–300 mg/kg daily in 3–4 divided doses. For neonates: The dose for less than 7 days or lesser than 2 kg, that is, 150 mg/kg daily in 3 divided doses; for more than 7 days and more than 2 kg, that is, 300 mg/kg in 3–4 divided doses, IV route is preferred for infants and children. Single dose more than 500 mg should not be given via IM injection.

Parenteral: For mild or uncomplicated infections: The adult dose as sodium is 100–125 mg/kg daily, the usual dose, if given via IV injection/infusion is 2 g every 6 or 8 h or 4 g every 12 h, if given via IM injection the dose is 2 g every 8 or 12 h. Prophylaxis of infection during surgery, for adults: as sodium the dose is 2 g just before the procedure or when the umbilical cord is clamped in caesarean section, followed by at least two doses of 2 g at intervals of 4 or 6 h within 24 h of procedure.