Intramuscular imipenem/cilastatin in multiple-dose treatment regimens: review of the worldwide clinical experience.

Multicenter noncomparative trials of intramuscular administration of imipenem/cilastatin for the treatment of a variety of infections requiring multiple-dose therapy are reviewed. Fourteen centers in the United States and 18 centers elsewhere participated in these studies. A total of 686 patients (461 evaluable) were treated worldwide. The severity of the infection was rated as moderate in 58.9%, mild in 37.2% and severe in 0.6%. The most common sites of infection were the skin and soft tissue (36.2%) and intra-abdominal (17.6%). Polymicrobial infections were relatively common (27%). Dosing regimens in evaluable patients were 500 mg every 12 h (45.1%), 750 mg every 12 h (36.2%) and 500 mg every 8 h (18.6%). The overall clinical outcome was favorable (clinical cure or improvement) for 95% or more of the evaluable patients with the various body system infections, except in gynecologic infections where 89% of the evaluable patients had a favorable outcome and for sepsis where the favorable outcome was 76%. Where data were available for analysis (skin and soft tissue infections) there was no difference in favorable clinical outcome among patients with moderate infection treated with 1.0 g/day (95% favorable) compared with 1.5 g/day (94% favorable). The overall bacteriologic eradication rate was 91%. Clinical adverse effects were similar in type but less common in frequency than those noted in other studies with the intravenous formulation, with nausea, vomiting and diarrhea being most common; no instances of seizures or confusion were observed. The laboratory adverse effects were similar to those seen in other studies with the intravenous formulation, with increased liver enzyme values the most common. The intramuscular injection was well tolerated in 87% of the patients and moderately well tolerated in 6.6%. The efficacy and low incidence of side effects of the intramuscular formulation of imipenem/cilastatin are significant advantages in the cost-effective treatment of infections.