Doripenem pharmacokinetic study will be carried out during the doripenem therapy. Blood samples (approximately 2 ml) in group " 0.5 g of doripenem with 4 h infusion every 8 h regimen" will be obtained by direct venepuncture at the following time: 0, 0.5, 1, 2, 3, 4, 4.5, 5, 6, 7 and 8 h after 7th dose of doripenem.