High-dose praziquantel for neurocysticercosis: efficacy and tolerability

Standard therapeutic regimens of praziquantel for neurocysticercosis use daily doses of 50 mg/kg for 15-21 days, with prolonged remission being achieved in 60-80% patients. In this prospective study, 100 mg/kg daily was used for 10 days in 13 patients aged 32 +/- 15 years (mean +/- SD) with severe intra-, extra-parenchymal or mixed forms of neurocysticercosis. Patients were monitored with computerized tomography and cerebrospinal fluid (CSF) examination on days 1, 5 and 10. Full blood count, sedimentation rate, blood sugar, urea, creatinine, bilirubin, liver transaminases, alkaline phosphatase, urine analysis and electrocardiogram were carried out before and after treatment. Doses of dexamethasone and of other drugs used concomitantly were controlled. There was no toxicity, clinical or detected by the methods employed in the study. After 22 +/- 5 (mean +/- SD) months follow-up, 6 patients needed ventriculoperitoneal shunting, 2 had died, 7 were improved and led useful lives and 4 were in prolonged remission. There was no correlation between serum or CSF praziquantel correlation and outcome of treatment. The proposed regimen is well tolerated, may be as efficient as previously advocated regimens, requires less hospitalization time and may be adopted routinely for therapy of neurocysticercosis.     

Serum and cerebrospinal fluid concentration of inflammatory proteins MIP-1-alpha and MIP-1-beta and of interleukin 8 in the course of borreliosis

Chemokines constitute a group of cytokines with a strong chemotactic action, playing an important role in the pathogenesis of inflammatory responses, including infectious meningitis. The results of in vitro experiments suggest synthesis of chemokines during Borrelia burgdorferi infection. The aim of this study was to investigate serum and cerebrospinal fluid (CSF) concentrations of the following chemokines: interleukin-8 (Il-8) and macrophage inflammatory protein 1 alpha and 1 beta (MIP-1 alpha and MIP-1 beta) in patients with neuroborreliosis. The study group consisted of 20 patients admitted to Neuroinfections and Infectious Diseases Department of the Medical University in Bia?ystok. The control group consisted of 12 healthy persons from whom blood samples were obtained, and 10 patients without meningitis, from whom CSF samples were taken for diagnostic purposes. Chemokine concentrations were measured with ELISA kits before treatment (baseline) and after 2 weeks of antibiotic therapy (post-treatment). Mean serum concentrations of chemokine were elevated in neuroborreliosis patients at baseline (Il-8--mean +/- SD = 668.25 +/- 661.51 pg/ml, MIP-1 alpha--124.90 +/- 89.37 pg/ml, MIP-1 beta--233.40 +/- 298.40 pg/ml) as compared to these in the control group (Il-8-23.72 +/- 7.68 pg/ml, MIP-1 alpha--36.81 +/- 4.74 pg/ml, MIP-1 beta--70.41 +/- 16.41 pg/ml). Post-treatment mean concentrations of Il-8 (197.70 +/- 285.56 pg/ml) and MIP-1 beta (102.70 +/- 42.56 pg/ml) remained significantly elevated, while the mean concentration of MIP-1 alpha (53.65 +/- 38.50 pg/ml) was insignificantly higher than that in the control group. The Il-8 mean concentration was the most elevated comparing to the controls and has decreased most significantly during the treatment. CSF concentrations of chemokines were significantly elevated both at baseline (Il-8--754.95 +/- 535.83 pg/ml, MIP-1 alpha--24.35 +/- 4.88 pg/ml, MIP-1 beta--27.6 +/- 8.38 pg/ml) and post-treatment (Il-8--98.20 +/- 74.74 pg/ml, MIP-1 alpha--18.60 +/- 2.87 pg/ml, MIP-1 beta--16.90 +/- 4.38 pg/ml) in comparison with the controls (Il-8--10.43 +/- 2.70 pg/ml, MIP-1 alpha--8.17 +/- 1.54 pg/ml, MIP-1 beta--7.27 +/- 1.58 pg/ml). MIP-1 alpha and MIP-1 beta CSF concentrations were significantly lower than their concentrations in serum. The Il-8 CSF concentration did not differ significantly from its serum concentration. However, in some patients Il-8 CSF concentration was much higher than that in the serum, which suggests its significant synthesis within the cns and its role in the pathogenesis of B. burgdorferi meningitis. Chemokine CSF concentrations were not correlated with cytosis and CSF protein concentration. The results indicate the induction of Il-8, MIP-1 alpha and MIP-1 beta synthesis in the course of neuroborreliosis and a decrease of their concentrations during 2 weeks of treatment, however, without reaching the normal values.     

Praziquantel in the cerebrospinal fluid in neurocysticercosis

In 10 patients with neurocysticercosis (NC), an assessment was made of the praziquantel (PZQ) concentration in the cerebrospinal fluid (CSF), in non-deproteinized serum and in protein-free serum: before administration of the drug and the 1st., 7th. and 21st. days of oral administration (50mg/kg/day during 21 days). Samples of CSF and blood were collected three hours after the last administration of the daily total dosage, on the 1st. and 21st. days; and from 2 to 6 hours after drug administration on the 7th. day. The total daily dosage was distributed into three equal parts of 1/3 each, with a 4 hours' interval between intakes, except in the last 5 cases, who on the 21st. day only were given the total daily dosage on a single administration. Results have shown dispersion in serum concentrations, which are similar to those seen in normal subjects as recorded in literature. There is a correlation between PZQ levels in the CSF and in the serum, the latter being very close to those found in protein-free serum fraction. The statistical treatment of results allowed the following considerations: PZQ concentrations in the CSF and in the protein free serum are in balance from the pharmacodynamic standpoint on the first day; this balance is maintained up to the 21st. day although at different levels from those seen on the 7th. day; on the 21st. day PZQ contents in CSF goes back to its similar values as recorded on the 1st. day, and this suggests that the participation of drug interaction factors has been reduced to non-significant levels. However, several factors can influence PZQ concentration in CSF, as absorption rate, liver first-pass effect and blood-brain barrier changes, and individual dose should be established for each patient based on drug concentration monitoring in the serum and/or in the CSF.     

Cerebrospinal fluid and serum neuron-specific enolase concentrations in a normal population.

The aim of this study was to determine cerebrospinal fluid (CSF) and serum neuron-specific enolase (NSE) concentrations in a normal population and to analyse their relationship with sex and age. The sample was recruited among patients undergoing spinal anaesthesia, without neurological diseases. NSE was determined by means of immunometric assay. One hundred and eight patients (68 men) were recruited. CSF-NSE concentration was (mean +/- SD) 17.3 +/- 4.6 ng/ml (men 17.4 +/- 4.2, women 17.0 +/- 5.2, P = 0.62); serum concentration was 8.7 +/- 3.9 ng/ml (men 8.9 +/- 3.9, women 8.3 +/- 4.0, P = 0.06). The mean CSF/serum NSE ratio was 2.3 +/- 0.8 (men 2.2 +/- 0.8, women 2.4 +/- 0.9, P = 0.22). In both sexes, simple regression analysis showed not significantly increasing concentrations with advancing age for both CSF and serum NSE. Serum and CSF concentrations did not correlate in both sexes. In our study, CSF-NSE was twice the serum concentration; both were not influenced by sex or age. Serum and CSF-NSE values vary widely among different studies on normal populations because of different determination methods; therefore, each laboratory should obtain its own reference values. Finally, serum NSE should be used with caution as an indicator of CSF concentration as no correlation could be demonstrated between them in our study.     

Time course of IL-6 expression in experimental CNS ischemia.

Interleukin-6 (IL-6) appears to be an important modulator of the inflammatory response associated with CNS ischemia. Clinically, IL-6 values obtained in the first week post-stroke have been shown to correlate with infarct size and outcome. In this study we used a focal reversible stroke model to investigate the time course and relationship to outcome of IL-6 production in plasma, brain and CSF. Reversible middle cerebral artery occlusion or sham surgery was produced in 50 adult Swiss Webster mice by advancing an 8-0 filament into the internal carotid artery for 2 h (sham 1 min). At 3, 6, 12, 24, and 72 h (8 each ischemia; 2 each sham) groups of animals were evaluated on a 28 point clinical scale, blood and CSF obtained, and the brains were evaluated for infarct volume and IL-6 mRNA levels. Serum levels of IL-6 (ELISA mean +/- SD; undetectable in controls) overall sham group, 102 +/- 87; 3 h, 908 +/- 494* pg ml-1; 6 h, 1079 +/- 468* pg ml-1; 12 h, 980 +/- 221* pg ml-1; pg ml-1; 24 h, 320 +/- 314* pg ml-1; 72 h, 20 +/- 30* pg ml-1 (*p < or = 0.05 to sham). CSF levels (ELISA) overall sham group, 10 +/- 18; 3 h, 379 +/- 210* pg ml-1; 6 h, 157 +/- 61* pg ml-1; 12 h, 136 +/- 88* pg ml-1; 24 h, 127 +/- 99 pg ml-1; 72 h, 72 +/- 9* pg ml-1 (*p < or = 0.05 to sham). Brain IL-6 mRNA levels overall sham group, 20; 3 h, 480; 6 h, 599; 12 h, 7960; 24 h, 20267; 72 h, 0. There was an overall R2 of 0.20 between plasma and CSF IL-6. There was an overall R2 of 0.13 and 0.20 between infarct size and serum and CSF IL-6 level respectively, and an overall R2 of 0.10 and 0.17 between neurologic function and serum and CSF IL-6 level respectively. These findings confirm that IL-6 values increase following CNS ischemia with peak serum and CSF levels occurring before brain values. CSF IL-6 levels had a stronger correlation with neurologic function and infarct size than serum.     

Blood and cerebrospinal fluid pharmacokinetics of the novel anticonvulsant levetiracetam (ucb L059) in the rat

The temporal pharmacokinetic interrelationship of levetiracetam in blood and cerebrospinal fluid (CSF) was studied after acute intraperitoneal administration of levetiracetam (20, 40 and 80 mg/kg), using an animal model that permits concurrent blood and CSF sampling in freely moving rats. After administration, levetiracetam rapidly appeared in both serum (time to maximum concentration (Tmax) mean range 0.25 0.50 h) and CSF (Tmax mean range 1.33-1.92 h), suggesting ready penetration of the blood brain barrier. Both serum and CSF levetiracetam concentrations rose essentially linearly and dose-dependently, suggesting that transport across the blood-brain barrier is not rate limiting over the levetiracetam concentration range observed in the present study. However, while apparent elimination half-life (t1/2) values for both serum and CSF were dose-independent (mean value range 1.8-2.8 and 4.4-4.9 h, respectively), t1/2 values for CSF were significantly larger. As the serum free/total serum levetiracetam concentration ratio (free fraction) was 1.01+/-0.02 (mean+/-S.E.M.), it can be concluded that levetiracetam is not protein bound. Furthermore, the free fraction was indistinguishable from that of the CSF/serum levetiracetam concentration ratio at equilibrium. It can be concluded that the kinetics of levetiracetam, in the rat, is simple and, thus, dosing strategies in studies designed to elucidate its mechanism of action should be straightforward.     

Serum and urine nitrate and nitrite are not reliable indicators of intrathecal nitric oxide production in acute brain injury

This study examined the correlation between nitric oxide (NO) metabolites in the three major body fluid compartments and assessed performance of newly described vanadium-based assay for simultaneous detection of nitrite and nitrate (NO(x)) in human samples. Vanadium reduces nitrate to nitrite, which can be measured after a colorimetric reaction with Griess reagents.Cisternal cerebro spinal fluid (CSF), serum and urine samples from 10 patients with acute brain injury (ABI) were compared to control subjects. Significantly higher CSF NO(x) levels were found in brain injury patients compared to control patients (19.7+/-13.7 vs. 6.5+/-2.3 microM; p=0.01), which persisted for 10-day period of observation. The serum and urine levels of NO(x) on admission were not statistically different (42.8+/-28.2 microM; 584.1+/-337.8 micromol/g Cr, respectively) from controls (36.8+/-14.8 microM; 819.7+/-356.0 micromol/g Cr), but tended to decrease during the disease course reaching the lowest level on day 6 (serum: 19.3+/-8.4 microM, urine: 300.4+/-111.9 micromol/g Cr). CSF levels of NO(x) correlated moderately with those in serum (p=0.001, R=0.5). Serum NO(x) concentrations correlated weakly with urine levels (p=0.04, R=0.3). There was no significant correlation between CSF NO(x) and urine NO(x) levels.In conclusion, patients suffering brain injury had increased NO(x) concentrations in CSF, which remained independent from other body fluid compartments. Serum and urinary NO(x) levels cannot be used as a reliable index to assess intrathecal NO production.     

Comparison of Single- and Repeated-Dose Pharmacokinetics of Diazepam

Summary: Purpose: To determine whether repeat boluses of diazepam (DZP) lead to significant accumulation in the central nervous system and/or peripheral compartments, as repeat intravenous boluses of diazepam are commonly used in the treatment of status epilepticus (SE).
Methods: In a rat model that permits simultaneous serum and cerebrospinal fluid (CSF) sampling, we characterized the pharmacokinetics of DZP and its metabolite, desmethyldiazepam, in CSF and blood using HPLC. DZP was administered by intraperitoneal injection as either a single dose (20 or 30 mg/kg) or repeat doses (10 or 20 mg/kg × 3, 1 h apart).
Results: After a single intraperitoneal dose, DZP was rapidly absorbed with a time to maximum concentration of 10 min. The serum concentrations then declined biexponentially. DZP rapidly entered the CSF; the CSF to serum ratio reached equilibrium within 10 min, and was equivalent to the ratio of free to total serum concentration. Repeated DZP dosing resulted in a threefold decrease in volume of distribution and clearance (p < 0.001). This was reflected in the CSF concentration data; how-ever, after the third dose, the ratio of CSF to serum concentration, also increased greatly, representing further persistence of DZP in the CSF compartment.
Conclusions: Repeat dosing of DZP leads to substantial accumulation, and high, persistent serum and CSF concentrations, which may explain the toxic effects of repeat DZP dosing. Repeat dosing of DZP using a tapering protocol, however, may increase the effectiveness of DZP in treating SE by preventing relapses without substantially increasing toxicity.     

Pharmacokinetics of 10-OH-carbazepine, the main metabolite of the antiepileptic oxcarbazepine, from serum and saliva concentrations

After administration of 600 mg of the antiepileptic oxcarbazepine to 7 healthy volunteers, serum and stimulated saliva samples were collected for the next 72 h. Concentrations of 10-OH-carbazepine, the main metabolite of oxcarbazepine, were determined by an HPLC method. The time-concentration curves showed a median Tmax of 8 h followed by a plateau until 24 h indicating saturable kinetic processes. Based on the curves, the pharmacokinetic parameters were calculated. The half-life of 10-OH-carbazepine in saliva, 13.8 +/- 3.7 (SD) h, was significantly shorter than in serum, 19.3 +/- 6.2 (SD) h. The half-life of 10-OH-carbazepine in serum was inversely correlated to the free fraction, estimated by the ratio saliva/serum concentrations. Calculation of free fraction by this method showed that 53.1 +/- 14.4 (SD) % of 10-OH-carbazepine is unbound in serum. There was a good correlation (r = 0.914) between serum and saliva concentrations of 10-OH-carbazepine from 8-72 h after administration of oxcarbazepine. This finding indicates that saliva concentrations may prove useful, as has been shown for carbamazepine, in therapeutic monitoring of oxcarbazepine treatment.     

Effect of the treatment with methylprednisolone on the cerebrospinal fluid and serum levels of CCL2 and CXCL10 chemokines in patients with active multiple sclerosis

BACKGROUND: Several experimental and human studies suggest that the chemokines CCL2 and CXCL10 may play a role in the pathogenesis of multiple sclerosis (MS). Here, we evaluated the effect of intravenous methylprednisolone (IVMP) therapy on the levels of CCL2 and CXCL10 in the cerebrospinal fluid (CSF) and serum of patients with active MS. METHODS: Serum and CSF samples were obtained from 14 patients with active relapsing-remitting MS (age +/- SD years, 37.0 +/- 8.1; M/F, 6/8) and age- and gender-matched control subjects. All patients were submitted to IVMP treatment (500 mg daily for 5 days). Blood and CSF sampling were performed at admission, i.e. before treatment (day 0), at the end of the treatment (day 6) and 30 days after treatment (day 30). The clinical status of MS patients was also assessed. CCL2 and CXCL10 were measured by enzyme-linked immunosorbent assay. RESULTS: Multiple sclerosis patients had lower CCL2 and higher CXCL10 in CSF when compared with control subjetcs. After treatment with methylprednisolone, MS patients showed clinical improvement and the CSF concentrations of CCL2 and CXCL10 modified toward normal values. CONCLUSIONS: The clinical improvement of active MS following the treatment with methylprednisolone was associated with the modification of CSF levels of CCL2 and CXCL10, suggesting that these chemokines may be useful markers of response to treatment and relapses in MS patients.