Abstract
Paromomycin sulfate (Aminosidine; Kyowa-Hakko Kogyo Co. Ltd., Tokyo) is a poorl y absorbed antibiotic produced by Streptomyces chrestomyceticus. It has been widely used in the treatment of bacterial and some protozoan diseases. The observation of ULIVELLI (1963) that patients treated for intestinal amoebiasis with paromomycin were cured of a concurrent Taenia infection, suggested its use in the treatment of intestinal cestodes.
The aim of the present study is to assess the efficacy and to investigate the mode of action of paromo mycin sulfate in the treatment of human and animal cestodiases.
1. Although the authors proved its efficacy against Diphyllobothrium latum in Golden hamster with a dosage schedule of over 60 mg/kg single, it was not effective against Hymenolepis nana in the mice with a dosage schedule of 2,000 mg/kg single or 100 mg/kg daily for 3 days.
2. A 100% cure rate was achieved in all patients of diphyllobothriasis latum (11 cases), diphyllobothriasis sp.(1 case), diplogonoporiasis grandis (1 case) and taeniasis saginata (5 cases) receiving paromomycin sulfate with a dosage of 35-50 mg/kg divided into 2 parts at an interval of 30 minutes. However, this drug was not effective in 1 case of hymenolepiasis diminuta.
3. In all expelled worms the scolex were not found. Histological observations revealed that the detachment of microtriches and destruction of tegument occurred on the body surface. The damages were most distinct in the neck and following immature proglottides.
4. The microbioassays for the amount of paromomycin sulfate remaining in the expelled worms indicated that the anterior part of worm body of D. latum contained the drug at the level of concentration range from 355 to 2,060 μg/g, but the amount decreased remarkably in the posterior part of the worm. Simillar results were obtained with Taenia saginata and Diplogonoporus grandis, however, with the less susceptible species as D. erinacei and Dipylidium caninum only a small amount of the drug would be detected. The drug was observed not effective against Hymenolepis nana. The worms isolated from animals treated even with the highest dosage of 2,000 mg/kg of the drug did not show any residue of the drug in the body.
5. It was confirmed that paromomycin sulfate was absorbed by suscepti ble species of cestodes and the absorption was mostly occurred in the anterior part of the body, particularly at neck and apparently at scolex. The higher degree of destruction of body surface observed by histological examinations in the anterior part than in the middle or posterior part of the worms coincided with the amount of drug absorbed.
6. It was strongly suggested that paromomycin sulfate causes the tegumental damage of susceptible cestodes mostly at the anterior most end of the worm body and leads to the detachment of whole body to expelling.
