A Diethylcarbamazine-Albendazole combination works much better in filariasis than Diethylcarbamazine alone, according to one of the largest randomized double blind study done to evaluate the combination. It involved 1500 subjects, and showed that 90 per cent of the filariasis-affected persons were free of the disease.
The trial, which was carried out with funding from the UNDP/World Bank/WHO and special program for research and training in tropical diseases (TDR) was the first trial conducted on such a large scale, which had enlisted more than 1500 subjects. The earlier studies did not have such large figures and were moreover restrained in hospitals alone.
The trial was smoothly collaborated by renowned experts including Dr B S Garg and Dr P R Deshmukh from KEM Hospital, Dr N S Ingole and Dr AM Mehendale from Mahatma Gandhi Institute of Medical Sciences (Sevagram Medical College), Wardha, Dr Lazdins and Dr Karbwang from the WHO, Geneva and Dr Fleckenstein from Iowa University, USA.
Dr Nilima Kshirsagar, Dean of the hospital and Dr Nithya Gogtay, from the Clinical Pharmacology department at KEM Hospital were the main investigators for the event.
For the trial, subjects for the study were recruited from two endemic villages, Kurzadi and Selukate, in the district of Warda in the state of Maharashtra, which was an endemic area of lymphatic filariasis and satisfying protocol requirements. Accordingly the study screened 2102 patients and planned to enroll 1347 subjects, half of whom received the single drug and the other half received the combination drug.
In the study, 698 patients received DEC alone while 705 patients received the combination. The number of subjects who experienced AEs did not differ significantly between the two treatment groups, nor did the effects on daily living. No serious AEs were detected during the study. Thus use of DEC+ALB is as safe as use of DEC alone and both the drugs were adequately absorbed, noted the study.
The study was carried out in India where studies in small number of patients had shown the safety and superiority of the combination, but a larger field study was necessary prior to incorporation of ALB along with DEC in national filariasis control programmes.
While safety analysis was primarily aimed at comparing the single drug versus the combination, analysis of whether age, sex and alcohol intake affected safety was also done. There was no difference seen between males and females, adults versus children and alcoholics versus non-alcoholics in the two groups.
Lymphatic filariasis is among the six diseases, which the WHO has recently declared can be potentially eliminated as public health problems. Moreover, filariasis control programmes are increasingly moving towards a strategy of repeated annual single-dose mass treatment of endemic populations. The current single dose treatment, which is being followed, is Diethylcarbamazine 6mg/kg body weight for 12 days.
The addition of ALB to DEC offers the advantages of both macrofilaricidal and antithelmintic actions. While the present field study has shown the combination of DEC+ALB to be as safe as DEC alone, in patients who participated in the efficacy study, there was no difference seen between DEC+ALB versus DEC alone at 12 months follow-up. The group has further recommended evaluation of efficacy between DEC and ALB+DEC at the end of three consecutive years of retreatment, a study that is presently ongoing.