Praziquantel(Distocide), the Korean product, was tested for its safety and efficacy in treatment of Clonorchis sinensis infection during the period from April to September, 1983 in Korea. A total of 55 egg positive cases were selected and treated with the regimen of 25 mg/kg t.i.d. for 1 day (total 75 mg/kg). The follow-up stool examination was done in 47 cases by cellophane think smear and Stoll's egg counting techniques. The 8 uncured cases were treated again with the same regimen. The laboratory tests for blood picture and liver function were done in 27 cases and compared before and after the treatment. The results obtained are as follows: After single course treatment, the cure and egg reduction rates were 83.0% and 99.1% respectively. With the second treatment, excellent results of 100% in both rates were obtained. Several kinds of side effects such as dizziness, headache, etc. were complained by 29 cases (61.7%), however, those were so mild and transient that no special treatment was necessary. No significant chang in laboratory findings was recognizable before and after the treatment. From the above results, it is concluded that Distocide is as effective and safe as Biltricide and highly recommendable in treatment of C. sinensis infection.
parasitology-helminth-trematoda ; Clonorchis sinensis ; treatment ; chemotherapy-praziquantel ; human ; praziquantel

Experimentally infected rats with 50 metacercariae of Clonorchis sinensis each were treated orally with different dosages of praziquantel. About 100 rats were divided into 8 groups in each developmental week after infection (from the first to 8th week after infection) and 24 rats served as untreated controls. In each developmental week after infection, about 15 rats divided into 4groups including control group(3 to 5 rats) were used to determine for the curative activity of praziquantel against C. sinensis. The experimentally infected rats in each developmental weeks after infection received praziquantel 1 x 100 mg/kg x 3 days , 3 x 100 mg/kg x 1 day and 3 x 100 mg/kg x 2 days. The effects of the drug were evaluated by the worm recovery rates, morphological changes of the worms and the number of eggs per gram of feces (EPG) after treatment. The feces of individual rats were collected once in a week at one week before and 4 weeks after treatment, and the number of Clonorchis eggs were examined by Stoll's egg counting method. The necropsy was performed on 4 weeks after treatment. The liver and the bile ducts were examined immediately after the dissection, and all of the worms recovered from the liver immersed in warm saline solution in a small petri dish in order to observe the motility of individual worms. After that, all worms obtained from the treated and untreated control rats were fixed in 10 percent formalin solution. The whole mount specimens were prepared by Semichon's acetocarmine stain for the study of morphlogical changes. In the treatment with dosage of 1 X 100 mg/kg for 3 consecutive days, relatively low worm recovery rates were shown in the early stages of infection than those of control groups. However there was no differences of the worm recovery rates between the later stages of infection (7 to 8 weeks after infection) and control groups. In the early stages of infection, the worms recovered in the bile ducts of each treated rats showed morphologically intact as normal control groups, however in the later stages of infection the worms showed damage of their reproductive organs such as testes, seminal receptacle and ovary etc. In the treatment with dosage of 3 X100 mg/kg X 1 day, the recovery rates of the worms in all developmental weeks after infection were considerably low and some growth inhibition of the worms were also noted. The worms recovered from the bile ducts in all developmental stages were seriously damaged in their reproductive organs, such as testes, seminal receptacle, ovary, Mehlis' gland, uterus and vitelline glands etc. The hyaline degenerations were also observed on the parenchymal tissues in the dead worms. The mean EPG values in this group were markedly reduced at the first 2 weeks after treatment. However the low values of EPG were generally noted at the 3rd to 4th week after treatment. On the other hand, in the treatment with dosage of 3 X 100 mg/kg X 2 days, no more the living worms was recovered in all developmental stages of Clonorchis . The dead worms recovered from the bile ducts were so seriously damaged that the morphological changes could not be observed. The mean EPG values in this group were markedly reduced during the first 2 weeks after treatment. At the 3rd week after treatment EPG value became negative in the most of all treated groups. No more the Clonorchis eggs were detected at the 4th week after infection, but only a very small numbers of eggs were found by the concentration method. From the above results, it is obvious that praziquantel exhibits a high degree of activity against Clonorchis sinensis in the rats, with no apparent differences in the efficacy against each developmental stage.
parasitology-helminth-trematoda ; Clonorchis sinensis ; chemotherapy-praziquantel ; rat ; praziquantel

A total of 60 patients with Hymenolepis nana infection were treated with a single oral dose of praziquantel in two different dose levels. Twenty-nine cases treated with praziquantel in a single dose of 15 mg/kg body weight produced a 100% cure rate. On the otehr hand, 30 out of 31 patients who received a single dose of 25 mg/kg body weight cured completely, but only one case had counts of 200 EPG of feces in each tests on the 20th and 21st days after treatment. The cure rate was 96.8% and the mean egg reduction rate of 99.8 per cent was obtained. Side effects were mild and transitory. In a few cases, abdominal pain, vertigo, headache and diarrhea were complained in a few hours after medication. Clinial hematology, serum biochemistry and urinalysis were performed immediately before and the next day after treatment in all cases. There were no significant abnormalities detected in these tests.
parasitology-helminth-cestoda ; Hymenolepis nana ; chemotherapy-praziquantel

The therapeutic effect of praziquantel on Fibricola seoulensis infection were studied by experimental infection of albino rats with the metacercariae obtained from the snakes. Total 51 albino rats were infected each with 500 or 1,000 metacercariae in number through intragastric tubes. One or four weeks later the rats were treated with 1, 5, 10 or 20 mg/kg sigle dose of praziquantel and sacrificed after 3 days or 10-120 minutes to search for the worms in their small intestine. The worms recovery rate at 3 days after the treatment was 10.7% in 1 mg/kg does group and 0.03-0.2% in 5, 10 and 20 mg/kg group, while that of untreated control was 51.3%. The minimum effective dose to treat F. seoulensis infection in the rats is considered to be 5 mg/kg in sigle dose. By observing the distribution pattern of worms in the small intestine after the treatment, dislodgment of the worms froms the duodenum, thier normal habitat, to the lower portion was recognizable within as early as 10 minutes. The majority of worms was found to have descended to the ileo-caecal portion after 60-120 minutes.
parasitology-helminth-trematoda ; Fibricola seoulensis ; chemotherapy-praziquantel

/A total of 69 patients of confirmed neurocysticercosis was followed serologically by ELISA up to 22 months after praziquantel treatment. The intervals and numbers of follow-up were variable by patients. Serially collected samples of serum and CSF were examined simultaneously for their specific IgG antibody levels by ELISA, using cystic fluid, saline extracts of bladder wall and scolex as antigen. Within 4 months after praziquantel treatment, the antibody levels were elevated temporarily in both serum and CSF in most patients. In some cases antibody levels exhibited steady declining tendency after the treatment. Concomitant administration of dexamethasone appeared to suppress the elevation of antibody levels. The rate of mean absorbance of antibody changed more in serum than in CSF. The rate of elevation was greater in antibodies to parenchymal antigens than that to cystic fluid, but absolute difference of antibody levels was greater in anitbody to cystic fluid. Previously negative samples for IgG antibody may become positive after praziquantel treatment, which could be used as a complementary tool(provocation test) in serodiagnosis. One month was considered to be sufficient interval for the follow-up test for that purpose. In the follow-up of up to 22 months, only few cases of chronic neurocysticercosis showed declining tendency of IgG antibody levels below negative range. During acute encephalitic attacks in chronic patients, IgG antibody to parenchymal antigen were elevated in CSF temporarily. These results indicated that serologic follow-up of every year was recommendable to differentiate the cured patients from chronic patients with slowly calcifying lesions.
parasitology-helminth-cestoda ; Taenia solium ; cysticercus ; brain ; immunology ; praziquantel-chemotherapy ; praziquantel

Five cases of Diphyllobothrium latum infection were proved by collection of worms after treatment with bithionol, niclosamide or praziquantel, during 1975-1983. The patients were 4 males and one female aged 10-64 years residing in Seoul or Wando-gun, Chollanam-do, Korea. All of them remembered the history of eating several kinds of raw marine fish and 2 persons said they ate the raw flesh of perch, Lateolabrax japonicus. Three among them experienced abdominal pain, 2 natural discharge of a chain of segments, but none revealed any sign of anemia. The average egg size in stool varied 59-67 x 41-48 micrometer according to cases. The eggs were characterized by ovoid to elliptical shape, terminal operculum, and distinct abopercular protuberance. One naturally discharged segment (30 cm) and 4 complete strobilae (320~680 cm) with scolices obtained after treatments were examined. The morphological characters of proglottids such as rosette-form uterus with 3-6 loops, vaginal pore included in the cirrus sac, separated seminal vesicle from cirrus sac etc. were all compatible with D. latum. These are the 7th~11th cases of D. latum infection proved by worms in Korea.
parasitology-helminth-cestoda ; Diphyllobothrium latum ; case report ; diphyllobothriasis ; chemotherapy-praziquantel ; niclosamide ; bithionol ; praziquantel

A total of 52 paragonimiasis patients was treated with praziquantel at three dose levels: 21 patients received 3 x 25.0 mg/kg bwt on a single day, 21 patients were treated with 3 x 25.0 mg/kg for 2 consecutive days and 10 patients were treated with the same dose for 3 consecutive days. Follow-up examination were carried out at monthly up to 4 months (120 days) after treatment. Fifteen (71.4%) out of 21 patients who received the drug 3 x 25.0 mg/kg bwt on a single day were parasitologically cured. Eighteen (85.7%) out of 21 patients who received 3 x 25.0 mg/kg bwt for 2 consecutive days were also cured. Six and 3 of uncured cases in each above groups were treated again with doses of 3 x 25.0 mg/kg bwt for 2 or 3 consecutive days. Two (consisting each one in each group ) of nine retreated cases were failed in parasitological cure. Therefore the overall cure rates of 95.2 % (20 out of 21 cases) in each group were finally obtained. On the other hand, in 10 patients who received 3 x 25.0 mg/kg bwt for 3 consecutive days, complete cure was obtained at 4 months follow-up examinations. Praziquantel is well tolerated and side effects consist particularly of mild and transient headache and dizziness. There was no great difference between the three dosage groups. Extended hematological and biochemical tests, and urinalysis, revealed no abnormal findings which could be related to the compound after therapy. The disappearance of precipitating bands of immunoelectrophoresis together with the disappearance of abnormal shawdows in chest X-ray after treatment gave a potent proof on assuring the cure of paragonimiasis.
parasitology-helminth-trematoda ; chemotherapy ; praziquantel ; paragonimiasis ; Paragonimus westermani

An experimental study was performed to observe the in vivo effects of praziquantel on the light and scanning electron microscopic morphology of Fibricola seoulensis. The metacercariae were obtained from the snakes and 1,000 in each number was orally given to total 15 albino rats; 5 controls and 10 treatment group. Seven days later the 10 rats were treated with 10 mg/kg praziquantel and sacrificed 1-24 hours later to search for the worms from their small intestines. The major light microscopic changes in the drug-exposed worms were early contraction followed by relaxation of especially their forebody, vacuolization of the tegument and subtegumental parechymal layers, and narrowing of the intestinal lumens. The scanning electron microscopic findings were characterized by formation of numerous blebs followed by rupture and subsequent destruction of their whole tegument. These results show that the change in worm body is not confined to the tegument but extends to deeper parechymal portions and also occurs in their intestines. It is suggested that the drug uptake by the worms should be either through their tegument or through the digestive tract.
parasitology-helminth-trematoda ; Fibricola seoulensis ; chemotherapy-praziquantel ; electron microscopy

The effect of praziquantel on P. westermani exposed in vitro was observed by stereomicroscope, light microscope and scanning electron microscope. Following results were found. The worms incubated in 0.01 micro-g/ml praziquantel were moving after 26-hour incubation. However, all of them were immobilized immediately after incubation in solutions over 0.1 micro-g/ml concentration. All of the exposed worms showed severe vacuolization not only in tegument but in subtegument, intestine, ovary, testis, Mehlis' gland and excretory bladder. Vacuoles in tegument burst out to form craters. As incubation time went on, tegumental structure was disintegrated severely. The worms exposed to praziquantel were observed to be immobilized and be vacuolized of all tissues. Disintegration of reproductive organs suggests that praziquantel have suppressive effect on egg production when the flukes are not killed. The drug effects were found more related with incubation time than with drug concentration.
parasitology-helminth-trematoda ; Paragonimus westermani ; electronmicroscopy ; chemotherapy ; praziquantel

The infection of Metagonimus yokogawai has been known to be present nationwidely and endemic in some parts in Korea. In order to select a highly effective compound against Metagonimus infections, the therapeutic effects were observed in 156 cases who were treated with several anthelmintic i.e. bithionol, niclosamide, niclofolan and praziquantel. All of the above drugs showed highly effective to the treatment of metagonimiasis by a single or two medication days. The egg reduction rates were in the range of 80.2 to 100 per cent. However, relatively low cure rates(8.3 to 37.5 percent) were observed in the groups treated by two doses of 30 mg/kg of bithionol, a single day treatment with 100 mg/kg of niclosamide and two doses of 1.0 mg/kg of niclofolan. On the other hand, the high cure rates were observed at the following dose rates of each drugs, i.e. the cure rate of 66.7 percent was obtained at two doses of 100 mg/kg of niclosamide, 88.9 percent of cure rate was observed at two doses of 2.0 mg/kg of niclofolan and a single dose of 10 and 20 mg/kg of praziquantel were shown as 85.0 percent and 88.0 percent of cure rates respectively. But the complete radical cure was obtained in the group treated by two doses of 20 mg/kg of praziquantel in 10 metagonimiasis cases. From the above results praziquantel was shown as the most highly effective against metagonimiasis and it was well tolerated without any side effect. Therefore, praziquantel is a very promising drug for mass treatment against metagonimiasis.
parasitology-helminth-trematoda ; Metagonimus yokogawai-metagonimiasis ; bithionol ; niclosamide ; niclofolan ; praziquantel ; chemotherapy