Albendazole and Praziquantel in Trichuris Infection

A randomized clinical trial was conducted to compare the effectiveness of albendazole alone and albendazole combined with praziquantel in the treatment of Trichuris trichiura infection. The drug regimens consisted of single dose of albendazole 400 mg (A1, n=34), 3 days of albendazole 400 mg daily (A3, n=34), 5 days of albendazole 400 mg daily (A5, n=35), single dose of albendazole 400 mg plus praziquantel 40 mg/kg (A1P1, n=34), and 3 days of albendazole 400 mg plus praziquantel 40 mg/kg daily (A3P3, n=36). It was found that treatment with 3 or more consecutive days of albendazole with or without praziquantel resulted in a significant reduction in density of Trichuris eggs in stools while a single dose of such drug did not. Praziquantel was not shown to have synergistic or antagonistic effects with albendazole. A regimen of 400 mg of albendazole daily for 3 days was found to be the most suitable therapy for Trichuris infection. Correspondence: Chukiat Sirivichayakul, Department of Tropical Pediatrics, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok 10400, Thailand. SOUTHEAST ASIAN J TROP MED PUBLIC HEALTH Vol 32 No. 2 June 2001 298 MATERIALS AND METHODS This was an open randomized clinical trial. A stool examination was done to detect Trichuris infected patients in communities. All children and adults who were infected with T. trichiura and met the following criteria were recruited: age more than 4 years; no history of allergic reaction to albendazole or praziquantel; no history of cysticercosis; no concurrent pregnancy, active liver or renal diseases, on other serious infectious illnesses. Informed consent was obtained from the patients or guardians. Pre-treatment stool examination using a modified Kato Katz technique (Martin and Beaver, 1969) was done to detect the density of Trichuris eggs in the stools. Pretreatment intensity of Trichuris infection was graded according to the density of egg in stool: grade 1, Trichuris eggs <100 eggs per gram of stool (epg); grade 2, Trichuris eggs 100-<1,000 epg; grade 3, Trichuris eggs 1,000<10,000 epg; and grade 4, Trichuris eggs ≥10,000 epg. The patients were then stratified randomly into 5 treatment groups (A1, A3, A5, A1P1, A3P3) depending on to the pretreatment intensity of infection. The treatment regimens were as follows: A1, single dose of albendazole 400 mg; A3, 3 consecutive days of albendazole 400 mg daily; A5, 5 consecutive days of albendazole 400 mg daily; A1P1, single dose of albendazole 400 mg plus praziquantel 40 mg/kg; A3P3, 3 consecutive days of albendazole 400 mg plus praziquantel 40 mg/kg daily. All drugs were administered orally as a single daily dose with breakfast. Both albendazole and praziquantel were produced by the Thai Government Pharmaceutical Organization. The patients were asked to report pre-treatment and post-treatment symptoms. Physical examination was done on day 0 and day 7 and whenever it was indicated by the presence of abnormal symptoms. The occurrence of post-treatment symptoms that were not present or that were more severe than that in the pre-treatment period was considered as side effects. Three consecutive stool examinations using a modified Kato Katz technique were performed 2-3 weeks after the last dose of treatment to assess the effectiveness of each regimen. This was done by investigators who were unaware of the treatment regimens. Cure was defined as no Trichuris eggs in all of the three post-treatment stool samples. Pre-treatment and post-treatment Trichuris eggs counts in each group were calculated as geometric mean eggs per gram of stool. To make calculation possible, the value of 0 epg was replaced by the value of 1. Paired t-test was used to compare pre-and post-treatment geometric mean eggs within the same group. The baseline and outcome data from different groups were compared and analyzed by analysis of variance (ANOVA) (continuous variables) for quantitative data and chisquare test or Fisher exact test for qualitative data whichever was appropriate. This study was approved by the Ethics Committee, Faculty of Tropical Medicine, Mahidol University, Bangkok.