Therapeutic effectiveness of a generic versus original meropenem in serious infections

Abstract

Background: Meropenem plays a significant role in the current antimicrobial treatment of serious infections. Recently, generic meropenems have become widely available in Thailand. Objective: Compare the effectiveness and safety of a generic meropenem (Mapenem®) with the original meropenem (Meronem®) in clinical practice.Material and Method: A retrospective cohort study was conducted in hospitalized patients with serious infections that had been treated with either the generic or the original meropenem in nine secondary- and tertiary-care hospitals nationwide. The treatment outcomes at days 3, 7, and 14 after the use of meropenem between the two groups were compared. Results: Three hundred ninety seven patients with a mean (SD) age of 66.4 + 16.9 years were included. There were 228 (57.4%) males and 169 (42.6%) females. Two hundred and seven (52.1%) and 190 (47.9%) cases fell into the generic and original groups respectively. There were no significant differences regarding age, gender, history of underlying disease, body weight, and ward of admission between the two groups. The majority of patients had presented with the respiratory tract (48.6%) and blood stream infections (29.5%). The three most common causative bacteria were Pseudomonas aeruginosa, Acinetobacter baumannii, and extended-spectrum beta-lactamase (ESBL) producing Escherichia coli. The distribution of the sites of infection, causative microorganisms, the dosage of meropenem, and duration of treatment were similar between the two groups. The distribution of patients with complete resolution, improvement, stable, worse, died from infection, and died from other causes were similar between the two groups at day 3, 7, and 14 of meropenem use (p > 0.05). The drugs were well-tolerated, and less than 2% of patients in both groups discontinued meropenem due to the adverse drug effects. Conclusion: The generic meropenem has a similar effectiveness in the treatment of serious bacterial infections when compared with original meropenem. Both formulations are well tolerated among patients with substantial comorbidities. Adverse drug effects that lead to drug discontinuation are uncommon.