• Fisheries and Aquatic Sciences
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• 제4권4호
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• pp.197-200
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• 2001

To investigate the re-treatment time of Microcotyle sebastis by oral administration of praziquantel, the residue levels of praziquantel in plasma of rockfish Sebastes schlegeli administered orally at a dose of 200 mg/kg B.W. were analyzed by reversed-phase HPLC, and the concentrations of praziquantel in the plasma were correlated with the extermination of M. sebastis. The absorption and depletion of praziquantel in the blood of rockfish were fast and the residual concentrations of praziquantel declined below $4\mu g/mL$ within 24 hr post treatment. Most of worms were exterminated within 3 hr after oral administration of praziquantel, however, a small number of M. sebastis were not killed by the treatment until end of the experiment. Considering fast drop of praziquantel in blood and extermination pattern of M. sebastis in the present results, retreatment at an interval of 9-12 hr would be effective for eradication of M. sebastis.

• Fisheries and Aquatic Sciences
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• 제5권2호
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• pp.141-143
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• 2002

The treatment efficacy of oral administration of praziquantel against the blood-sucking monogenean Microcotyle sebastis under the commercial rockfish-culture conditions was evaluated. The quantity of praziquantel added to the food was calculated so that the amount of praziquantel ingested daily by fish was 200mg or 400mg/kg body weight (bw). The fish were fed a moist-pelleted fish meal supplemented with praziquantel at an rate of 0 (control), 200 or 400 mg of praziquantel per kg bw, respectively, for 3 times at an interval of 24 h. On 1 day to 8 days after the treatment, 10 fish were taken randomly from each net-pen daily (80 fish in each group in total), and the efficacy of each treatment was confirmed. Abundance of worms were significantly reduced in groups fed praziquantel-supplemented diets. The results clearly demonstrated that feeding the praziquantel-supplemented diet was effective for controlling M. sebastis infestation in practical commercial rockfish-culture systems without imposing any handling stress.

• Parasites, Hosts and Diseases
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• 제49권1호
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• pp.73-77
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• 2011

Paragonimiasis is an infectious disease caused by trematodes of the genus Paragonimus. This trematode can be treated successfully with praziquantel in more than 90% of the cases. Although praziquantel is generally well tolerated, anaphylactic reactions to this drug have been reported in a few cases. We report here a 46-year-old Korean female with paragonimiasis, presumed to be due to Paragonimus westermani, who displayed an allergic reaction to praziquantel and resistance to triclabendazole treatment. The patient was successfully treated with praziquantel following a rapid desensitization procedure. Desensitization to praziquantel could be considered when no alternative drugs are available.

• 대한수의학회지
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• 제30권4호
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• pp.479-485
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• 1990

This study was carried out to observe in vitro effect of praziquantel on the viability and internal organ changes of Heterophyopsis continua with light microscopy. Metacercariae were collected from the perch, Lateolabrax japonicus, by artificial digestion technique and fed to 2-week old chickens. Adult worms were recovered from the small intestines of chickens 8 days after infection. For working solutions, praziquantel was diluted with TC199 medium at the concentration of 0.01, 0.1, 1 and $10{\mu}g/ml$. To each petri dish containing 10ml of solution, 5~10 worms were introduced and incubated at $37^{\circ}C$. Motlity of worms was observed at 5, 15, 30, 60 minutes, 1, 2, 4 and 6 hours after incubation. For light microscopy, worms were fixed in 10% formalin under cover glass pressure and stained with Semichon's acetocarmine. The results were as follows: 1. In $0.01{\mu}g/ml$ praziquantel, the worms had their mobility until 6 hours post treatment. However, worms in over $0.1{\mu}g/ml$ of praziquantel contracted within 5 minutes and immobilized. 2. Intestine of the worm incubated in $0.001{\mu}g/ml$ praziquantel for 5 minutes was dilated and intestinal wall was thickened. 3. In incubated over $0.1{\mu}g/ml$ praziquantel, pharynx of the worm protruded out from oral sucker. 4. The lowest effective lethal concentration of praziquantel on H. continua was $0.1{\mu}g/ml$. The worms exposed to the drug were observed to be immobilized immediately after incubation in solutions of over $0.1{\mu}g/ml$ concentration. All of the worms in early period showed severe contraction and those in late period showed severe dilation.

• Parasites, Hosts and Diseases
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• 제25권1호
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• pp.24-36
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• 1987

Praziquantel이 폐흡충에 미치는 영향을 광학 및 주사전자현미경으로 관찰하기 위하여 본 연구를 수행하였다. 가재에서 분리수집한 폐흡충의 피낭유충을 2마리의 개에 경구감염시키고 11주후에 도살하여 폐로부터 128마리의 성충을 회수하였다. Tyrode 용액에 prasiquantel을 0.01, 0.1, 1, 10, 1000mg/m1 농도로 희석하여 배양액으로 사용하였다. 배양액에 활발히 움직이는 충체를 8마리씩 넣고 $37^{\circ}C$에서 배양하면서 15분, 30분, 1시간, 6시간, 12시간, 26시간에 운동성 및 형태학적 변화를 해부현미경으로 관찰하였다. 또한 각 실험군의 충체를 광학 및 주사전자현미경 표본으로 제작하여 관찰하였다. Praziquantel에 작용된 충체는 즉시 수축하고 점차 이완되었으며 표피와 표피하층의 공포화, 소화관의 수축과 내강의 팍장, 소화관벽의 비후, 난소와 고환의 공포화 및 말단의 구형화, Mehlis선의 공 포화등이 관찰되었다. 주사전자현미경적 소견으로 소수포의 형성은 구흡반과 복흡반 사이의 표면에서 가장 먼저 관찰되었고 배양시간과 praziquantel의 농도가 증가합에 따라 전체표면으로 확산되었다. 고농도의 배양액에 배양한 충체의 측후방 표피에는 분화구모양의 손상이 관찰되었으며 점차 전체표피로 확산되었다. Praziquantel의 작용을 받은 폐흡충의 형태학적 변화는 표피뿐만 아니라 소화기관, 생식기관 기타 조직등 전부위에서도 일어나는 것이 관찰되었다. 특히 충체가 살아있는 농도에서도 생식기관이 파괴되어 산란에 지장을 초래할 것으로 예상된다. 이와같은 변화는 pragiquantel의 농도보다 배양시간에 보다 더 영향을 받는 것으로 보인다.

• 약학회지
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• 제34권1호
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• pp.40-46
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• 1990

Pharmacokinetic studies on praziquantel in rabbits were performed in this paper. The pharmacologically active parent drug was separated from the pharmacologically inactive metabolites by HPLC method. The pharmacokinetic parameters of parent drug were obtained. In vitro partition to blood cells of praziquantel was measured. The mean value (n = 3) of partition to blood cells was 44% at concentrations between $1\;{\mu}g/ml$ and $40\;{\mu}g/ml$. Therefore, the relatively high partition to blood cells should be considered in further pharmacokinetic studies on praziquantel.

• Parasites, Hosts and Diseases
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• 제49권3호
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• pp.273-275
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• 2011

Praziquantel is the drug of choice for clonorchiasis. Since clonorchiasis is endemic in most river basins, praziquantel has been widely used for 30 years in Korea. A 54-year-old Korean woman suffered from hypersensitive reactions, such as nausea, dyspnea, rash, and urticaria after taking the first dose of praziquantel to treat clonorchiasis. She ingested one dose again and the same symptoms appeared, and she was treated at a clinic with anti-histamines. She tried one more dose with anti-histamines but found the same symptoms. Later, she was found to pass eggs of Clonorchis sinensis and medicated with flubendazole. The hypersensitive reaction to praziquantel is rare but occurs. This is the 5th case report in the world.

• Parasites, Hosts and Diseases
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• 제39권4호
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• pp.285-292
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• 2001

The present study aimed to evaluate control efficacy of clonorchiasis by two schemes of repeated treatment with praziquantel at two endemic villages in China. Residents of one village at Guangxi Autonomous Region were treated and examined 6-monthly and of another at Liaoning Province 12-monthly, In residents that took 25 mg/kg x3 (total 75 mg/kg) of Praziquantel every 6 months for one Year the e99 Positive rate showed a significant drop from 69.0% to 17.1%. In contrast, a group of same praziquantel medication once showed a slight marginal decrease in the egg rate from 18.9% to 12.2% after one year Of 39 subjects examined 3 times, 56.4% were cured, 7.7% persistently positive, one (2.6%) reinfected after cure or newly infected, but 25.6% were persistently negative. The present finding suggests that 6-monthly medication with 75 mg/kg of praziquantel should effectively lower the prevalence but incomplete for control of clonorchiasis in heavy endemic areas.

• Molecular & Cellular Toxicology
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• 제3권3호
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• pp.195-197
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• 2007

Currently praziquantel is used for treatment of not only clonorchiasis but also other trematodes and cestodes. But cure rate of praziquantel is just 60-80% for most trematodes. It needs for the treatment-failed patients to have more drugs. The cause of failure of treatment is not studied. We just know that the blood level of praziquantel is severely different among the people. We guess that this factor may influence the results of treatment. In an endemic area of human clonorchiasis in Heilongjiang Providence, China, 78 subjects were selected for the study. Three doses of 25 mg/kg (total 75 mg/kg) of praziquantel were administered to 78 clonorchiasis patients. After three weeks of treatment, stool examination was undertaken once again to confirm the cured and uncured subjects. To analyze SNP (single nucleotide polymorphism) of CYP3A5 PS2-1, CYP3A5 PS2-2, and CYP3A5*6, PCR method was done with specifically designed primers. The mutation rates of all sites were not significant statistically. The number of subjects was too small, so we need more subjects and other delivery proteins of bile ducts (ex. MRP etc.) were also considered for effects of praziquantel. We analyzed, for the first time, the entire CYP3A5 gene in a French population, using a polymerase chain reaction- single strand conformational polymorphism (PCR-SSCP) strategy.

• Archives of Pharmacal Research
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• 제21권6호
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• pp.744-748
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• 1998

Several praziquantel derivatives have been prepared by the acylation of compound 5, and examined on their biological activity in vitro agninst adult clonorchis sinensis collected from rabbits infected with metacercariae which was isolated from Pseudorasbora parva, a second intermediate host, captured in Nakdong river in Korea.