[Determination of praziquantel levels in cerebrospinal fluid and plasma in patients with cysticercosis of the central nervous system treated with praziquantel].

The CSF and plasma concentrations of praziquantel (PZQ) were determined with high pressure liquid chromatography in 37 patients with cysticercosis of the central nervous system during a dosing regimen of PZQ 20 mg/kg p o q 8h for 3 days. The pharmacokinetic parameters were estimated using the nonlinear least squares method. The results showed that PZQ could pass through the blood-brain barrier. The absorption and elimination rates in CSF were slower than those in plasma, the corresponding mean levels being 0.1 and 0.27 micrograms/ml, which were lower than those in plasma. There was a linear correlation between CSF and plasma concentrations (r = 0.87, P less than 0.01). The neurological complications during the period of therapy were not related to the CSF level of PZQ. The cure rates of muscular and cerebral cysticerci were 14/14 and 5/37 respectively. The difference in susceptibility was considered to be caused by the pharmacokinetic behavior of PZQ and CSF and plasma. It was suggested that in general favorable regimens had better be adjusted with adequate increase of the dosage of PZQ, shortening the dosing interval, and prolong the period of PZQ treatment, but individualization of the PZQ dosing regiment would be necessary in accordance with the plasma concentration of the PZQ.