Praziquantel

We investigated the pharmacokinetic characteristics of praziquantel (PZQ) in rice field eels Monopterus albus. Pharmacokinetic parameters were determined following a single intravenous administration (5 mg kg-1 body weight [bw]) and a single oral administration (10 mg kg-1 bw) at 22.0 ± 0.7°C. We also evaluated residue depletion in tissues following daily administration of PZQ (10 mg kg-1 bw) that was given orally for 3 consecutive days at 22.0 ± 0.7°C. Following intravenous treatment, the plasma concentration-time curve was best described by a 3-compartment open model, with distribution half-life (t1/2α), elimination half-life (t1/2β), and area under the concentration-time curve (AUC) of 0.54 h, 17.10 h, and 14505.12 h µg l-1, respectively. After oral administration, the plasma concentration-time curve was best described by a 1-compartment open model with first-order absorption, with absorption half-life (t1/2Ka), elimination half-life (t1/2Ke), peak concentration (Cmax), time-to-peak concentration (Tmax), and AUC estimated to be 2.

Puag-Haad is a traditional anthelmintic drug used to treat taeniasis in Thailand and Lao PDR. It is derived from the aqueous extract of the plant Artocarpus lakoocha. We investigated the in vitro anthelmintic properties of Puag-Haad against Schistosoma mansoni. Adult worms were incubated in M-199 medium containing 250, 500 and 750 μg/ml of Puag-Haad or praziquantel (PZQ) at a concentration of 175 μg/ml for 3, 6, 12 and 24 hours. The relative motility (RM value), survival index (SI) and tegument alterations seen under scanning electron microscope were assessed at each incubation time. The results showed the crude extract of A. lakoocha at a concentration of 250 μg/ml was more effective in causing damage than PZQ at a concentration of 175 μg/ml using RM and SI values. The major target organ affected by Puag-Haad was the tegument. The damage was greater at higher concentrations of the crude extract. It is likely tetrahydroxystilbene (THS), the main compound in Puag-Haad, caused the damage.

Cystic echinococcosis (CE) is a widespread zoonosis caused by the species complex Echinococcus granulosus. Albendazole (ABZ)-the first-line anthelminthic drug for medical treatment of CE-is metabolized in vivo to the active derivative ABZ-sulphoxide (ABZ-SO). Target-site ABZ-SO concentrations in the hydatid cyst mediate the anthelminthic effect in CE. Primary outcome of this systematic review of individual patient data was the intra-cystic ABZ-SO concentration stratified by cyst size, location, calcification status and use of praziquantel. Studies reporting intra-cystic ABZ-SO concentrations in humans were identified by a systematic search. A pooled analysis of individual patient data was performed to assess intra-cystic concentrations. Pharmacokinetic data of 121 individual cysts were analysed. There was no correlation between plasma and intra-cystic ABZ-SO concentrations (rho = -0.03, p = 0.76). Intra-cystic drug concentrations were also not associated with sex and treatment duration.

Surgical resection is traditionally the preferred treatment for fluorodeoxyglucose-avid peripheral pulmonary nodules that grow over time. However, new technologies, including electromagnetic navigational bronchoscopy (ENB), provide an opportunity to confirm or possibly exclude a cytologic cancer diagnosis, before resection. We present a case of a 56-year-old North American man who presented with a fluorodeoxyglucose-avid pulmonary nodule and sought a second opinion after being recommended thoracotomy with lobectomy. The peripheral nodule was biopsied using ENB and pathologic evaluation of the lesion demonstrated parasitic eggs with features of Paragonimus westermani. No evidence of malignancy was found. The radiographic abnormalities resolved after treatment with praziquantel. Using a minimally invasive procedure with ENB, we successfully diagnosed pulmonary infection with P. westermani, a rare infectious cause of peripheral pulmonary lesions in a patient without travel to an endemic area.