An open-label, prospective study of an oral polyvalent bacterial lysate (Luivac) in the treatment of recurrent respiratory tract infections in Thai patients.

An open-label, non-comparative study was performed in the Department of Otolaryngology, Siriraj Hospital, Bangkok, Thailand, to assess the safety, tolerability, acceptability and efficacy of an oral polyvalent bacterial lysate (Luivac) in the treatment of recurrent respiratory tract infections (RTIs) in Thai patients. Thirty-three patients were included in this study, 18 males and 15 females, with a mean age of 34.0 +/- 14.7 years. The mean number of RTIs during the 12-month period preceding the study was 9.5 per patient. During the study each patient received one tablet of Luivac daily for 28 days followed by a treatment-free period of 28 days. This was followed with another 28 days on Luivac, after which there was a 28-day treatment-free follow-up period. This study lasted 4 months with five scheduled patient visits (V1-V5). Laboratory studies were done at baseline (V1) and after treatment (V4), which included complete blood count and serum immunoglobulins (IgA, IgE, IgG and IgM). The incidence of all adverse events was 15.2% and no case was related to the studied drug. There were no clinical relevant changes in laboratory parameters after treatment. The reduction rate of RTIs per month at the end of the study period was 63.5% when compared to the average RTIs rate per month during the 12 months preceding the study. A comparison of the first study period (V1-V3) and the second study period (V3-V5) showed a reduction in duration of RTIs (23.1%), in the clinical infection score (17.5%), in the number of antibiotics used (2.1%), in the number of symptomatic treatments (3.5%), and in the number of days absent from school or work (50.0%). Overall tolerability and acceptability were assessed as very good and good in 96.8% of the patients. This study suggests that oral polyvalent bacterial lysate (Luivac) was safe and also showed a tendency to be effective in preventing RTIs in Thai patients with or without risk factors for recurrent RTIs. Other clinical advantages were reduction in the severity and duration of infection as well as in reduction of the cost of treatment and the number of days absent from school or work.