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Background: Central nervous system (CNS) compartmentalization provides opportunity for human immunodeficiency virus (HIV) persistence and resistance development. Differences between cerebrospinal fluid (CSF) and cerebral matter regarding HIV persistence are well described. However, CSF is often used as surrogate for CNS drug exposure, and knowledge from solid brain tissue is rare., Methods: Dolutegravir, tenofovir, lamivudine, and efavirenz concentrations were measured across 13 CNS regions plus plasma in samples collected during autopsy in 49 Ugandan decedents. Median time from death to autopsy was 8 hours (interquartile range, 5-15 hours). To evaluate postmortem redistribution, a time course study was performed in a mouse model., Results: Regions with the highest penetration ratios were choroid plexus/arachnoid (dolutegravir and tenofovir), CSF (lamivudine), and cervical spinal cord/meninges (efavirenz); the lowest were corpus callosum (dolutegravir and tenofovir), frontal lobe (lamivudine), and parietal lobe (efavirenz). On average, brain concentrations were 84%, 87%, and 76% of CSF for dolutegravir, tenofovir, and lamivudine, respectively. Postmortem redistribution was observed in the mouse model, with tenofovir and lamivudine concentration increased by 350% and efavirenz concentration decreased by 24% at 24 hours postmortem., Conclusions: Analysis of postmortem tissue provides a unique opportunity to investigate CNS antiretroviral penetration. Regional differences were observed paving the way to identify mechanisms of viral compartmentalization and/or neurotoxicity., Competing Interests: Potential conflicts of interest. All authors: No reported conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2024. Published by Oxford University Press on behalf of Infectious Diseases Society of America. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: People living with human immunodeficiency virus are ageing under combination antiretroviral treatments but data on drug exposure in serum and cerebrospinal fluid are limited. Dolutegravir is a widely used second-generation integrase strand transfer inhibitor: conflicting data suggest that neuropsychiatric side effects may present at a higher frequency in patients with higher dolutegravir serum concentrations., Methods: We performed a retrospective analysis of our therapeutic drug monitoring registry identifying patients receiving once-daily dolutegravir without concomitant interacting drugs and significant clinical conditions. Data were analysed stratifying time after drug dose intake (maximum concentration 0.5-4 and trough concentration 21-27 h). Cerebrospinal fluid samples from patients enrolled in neurological studies and receiving dolutegravir were analysed for dolutegravir cerebrospinal fluid concentrations and cerebrospinal fluid-to-plasma ratios. Serum and cerebrospinal fluid concentrations were measured through validated chromatographic methods., Results: We included 207 (providing 457 serum samples) and 41 patients (providing 41 cerebrospinal fluid samples). Participants were mostly male (68.2-72.8%) of median age of 50 years (50-53 years). Non-significant changes in dolutegravir maximum concentration and trough concentration were observed with age at Spearman's test (p values > 0.05); linear logistic regression showed a significant effect of age on dolutegravir trough concentration (p = 0.0013) (Fig. 1). Dolutegravir maximum concentration [3830 ng/mL (2311-5057) vs 4230 ng/mL (2919-5272), p = 0.311] and trough concentration [838 ng/mL (362-1587) vs 966 ng/mL (460-2085), p = 0.056] were non-significantly or borderline higher in patients aged > 50 years. Cerebrospinal dolutegravir concentrations were associated with plasma concentrations (ρ = 0.374, p = 0.016) and age (ρ = 0.537, p = 0.003); cerebrospinal fluid dolutegravir concentrations (13.8 vs 7.3 ng/mL, p = 0.015) and cerebrospinal fluid-to-plasma ratios (0.57 vs 0.32%, p = 0.017] were higher in participants aged > 50 years., Conclusions: We observed an increase in dolutegravir exposure in serum and in cerebrospinal fluid in older patients living with human immunodeficiency virus.

Farnesyl pyrophosphate synthase (FPPS) is known to participate in a variety of disease-related cell signaling pathway and bisphosphonates (BPs) are served as FPPS inhibitors. However, the high polarity of BPs often induces a series of side effects, limiting their applications. In the present study, novel non-BP FPPS inhibitors were discovered by in silico screening and experimental validation. From the structure-based virtual screening (SBVS) strategy combining molecular docking, pharmacophore and binding affinity prediction, 10 hits with novel scaffolds were filtered. The inhibition activity of hits against FPPS was identified and 7 hits showed comparable or higher inhibition activity than Zoledronate. The hit VS-4 with higher lipophilicity (XlogP = 1.81) and binding affinity (K D  = 14.3 ± 2.63 μM) to FPPS was selected for further study on cancer cells with different FPPS expression level. Experimental results revealed that VS-4 could better target the FPPS high-expressing colon LoVo and HCT116 cancer cell lines with IC 50 of 51.772 ± 0.473 and 43.553 ± 1.027 μM, respectively, whereas the IC 50 value against FPPS low expressing MDA-MB-231 cells was >100 μM. The mechanism of VS-4 against colon cancer cells was investigated by flow cytometry and the results indicated that VS-4 induced cell apoptosis by increasing the intracellular reactive oxygen species (ROS) level. Taken together, the SBVS strategy could be used to discover promising non-BP FPPS inhibitors and the lead compound VS-4 might shed a light on designing more potent inhibitors as novel anticancer drugs., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

Dopamine D₂ receptor partial agonists represent a new generation of atypical antipsychotics. Cariprazine, which has received centralized market authorization from the European Medicines Agency in 2017 for the treatment of adult patients with schizophrenia (including those with predominant negative symptoms of schizophrenia) differs from the other two partial agonist antipsychotics aripiprazole and brexpiprazole due to its unique features. Cariprazine is a dopamine D₃ preferring D₃/D₂ partial agonist with very similar dopamine receptor subtype selectivity as dopamine. It has proven efficacy in the treatment of positive and negative symptoms of schizophrenia, as well as for relapse prevention. Further phase-3 clinical studies proved the efficacy of cariprazine in the acute treatment of manic or mixed episodes associated with bipolar I disorder, as well as in bipolar depression. For the adjunctive treatment of major depressive disorder, phase 3 studies are in progress.

Background: Osimertinib demonstrated promising efficacy for refractory leptomeningeal metastases (LM) in preclinical data and a clinical study at 160 mg, but there is limited data for the standard 80 mg dose., Methods: T790M-positive patients with suspected LM after classical epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) failure were enroled., Results: We investigated 13 patients (5 definitive and 8 possible LM cases). In two of the five definitive cases with T790M in and outside the central nervous system (CNS), osimertinib was effective for both lesions, with cerebrospinal fluid (CSF) clearance of cancer cells and sensitive/T790M mutations. In three definitive cases with extra-CNS T790M without CSF T790M, cancer cells and sensitive mutations in the CSF persisted after osimertinib initiation. The median progression-free survival of all 13 patients was 7.2 months. Osimertinib was generally well-tolerated despite poor performance status, but interstitial lung disease (grade 2) was confirmed in one patient. Based on 25 samples from 13 patients, the osimertinib CSF penetration rate was 2.5±0.3%., Conclusions: Osimertinib 80 mg is a useful therapeutic option for refractory LM after classical EGFR-TKI failure. It appears more effective in CSF T790M-positive cases.

Imatinib mesylate (STI571) is a very effective treatment option for Ph(+) chronic myeloid leukemia (CML) in chronic phase. Secondary treatment failures have mostly been observed in patients with advanced stages of disease. We report the case of a patient who unexpectedly experienced blast crisis of the central nervous system although having achieved complete cytogenetic remission in the bone marrow. The levels of STI571 and its metabolite N-desmethyl STI were 40-fold lower in the cerebral spine fluid than in plasma. The risk of CNS disease has to be kept in mind when patients with CML in chronic phase who are at an increased risk for blastic transformation are treated with imatinib mesylate.

Isolated central nervous system (CNS) relapse occurred in 5 out of 24 patients (20.8%) with chronic myeloid leukemia (CML) lymphoid blast crisis (2), Philadelphia (Ph) chromosome positive acute lymphoblastic leukemia (ALL) (2) or CML with biphenotypic markers (1) treated on imatinib mesylate (IM) protocols at our institution. CNS relapse occurred despite peripheral blood (5) and bone marrow (3) complete responses. Median time to CNS relapse was day 32 (range 23 to 100). This observation raised the possibility that IM may not penetrate into the CNS. Simultaneous plasma and cerebral spinal fluid (CSF) IM levels were determined in four subsequent patients by liquid chromatography and mass spectrophotometric assay. Levels of IM were found to be approximately two logs lower in CSF than in plasma (0.044 microg/ml (0.088 +/- 0.029 micrro) vs 3.27 microg/ml (6.54 +/- 0.93 microM)). CSF levels were substantially below the concentration required for inhibition of BCR-ABL and killing of cell lines in vitro. These results suggest that IM may not penetrate the intact blood/brain barrier and its implications are discussed.

Despite the remarkable clinical response rates to imatinib in the treatment of bcr-abl leukemic patients, pharmacokinetic data on this relatively novel substance are needed to improve our understanding of the emergence of resistance, the interindividual variations of clinical response and the clinical and biologic relevance of its main metabolite N-desmethyl-imatinib. We present here pharmacokinetic data obtained with a newly designed HPLC approach in 97 patients with chronic myeloid leukemia or acute lymphatic leukemia (ALL) under treatment with imatinib that allowed us to calculate the AUC (39.5 microg.h/ml for an oral dose of 400 mg daily), the t(1/2) (18.2 h) and the peak concentration (1.92 micro/ml for an oral dose of 400 mg daily) of imatinib in plasma. In a subgroup of patients, the same parameters were analyzed for N-desmethyl-imatinib. We also provide data on the imatinib concentration in the cerebrospinal fluid (CSF) of ALL patients and demonstrate that oral administration of imatinib resulted only in a marginal flux across the blood-brain barrier. Finally, in an in vitro setting, we determined cellular concentrations of imatinib in HL-60 cells and showed an over-proportional uptake both in RPMI medium and in human plasma. Using an arithmetical approach combining all parameters obtained in imatinib-treated patients, we finally provide a conclusive approximation of basic pharmacokinetic data for both imatinib and its main metabolite N-desmethyl-imatinib.

Purpose: Imatinib mesylate (Gleevec, Glivec, STI571, imatinib) is a potent tyrosine kinase inhibitor approved for the treatment of chronic myelogenous leukemia and gastrointestinal stromal tumors. The role of imatinib in the treatment of malignant gliomas and other solid tumors is being evaluated. We used a nonhuman primate model that is highly predictive of the cerebrospinal fluid penetration of drugs in humans to study the pharmacokinetics of imatinib in plasma and cerebrospinal fluid (CSF) after i.v. and p.o. administration., Experimental Design: Imatinib, 15 mg/kg i.v. over 30 min (n = 3) or 30 mg/kg p.o. (n = 3), was administered to nonhuman primates. Imatinib was measured in serial samples of plasma and CSF using high-pressure liquid chromatography with UV absorbance or mass spectroscopic detection. Pharmacokinetic parameters were estimated using model-independent methods., Results: Peak plasma imatinib concentrations ranged from 6.4 to 9.5 microM after i.v. dosing and 0.8 to 2.8 microM after p.o. dosing. The mean +/-SD area under the plasma concentration versus time curve was 2480 +/-1340 microM.min and 1191 +/-146 microM.min after i.v. and p.o. dosing, respectively. The terminal half-life was 529 +/-167 min after i.v. dosing and 266 +/-88 min after p.o. dosing. After i.v. dosing the steady state volume of distribution was 5.9 +/-2.8 liter/kg, and the total body clearance was 12 +/-5 ml/min/kg. The mean peak CSF concentration was 0.25 +/-0.07 microM after i.v. dosing and 0.07 +/-0.04 microM after p.o. dosing. The mean CSF:plasma area under the plasma concentration versus time curve ratio for all of the animals was 5% +/-2%., Conclusions: There is limited penetration of imatinib into the CSF of nonhuman primates after i.v. and p.o. administration.

An isocratic online-enrichment HPLC-assay was developed allowing for the simple and fast separation and quantitation of STI-571 and its main metabolite N-desmethyl-STI (N-DesM-STI) in plasma, urine, cerebrospinal fluid (CSF), culture media and cell preparations in various concentrations using UV-detection at 260 nm. The analytical procedure consists of an online concentration of STI-571 and N-DesM-STI in the HPLC system followed by the elution on a ZirChrom-PBD analytical column. Time of analysis is 40 min including the enrichment time of 5 min. The detection limit is 10 ng/ml in plasma, CSF, culture medium (RPMI) and 25 ng/ml in urine for both STI-571 and N-DesM-STI. The intra-day precision, as expressed by the coefficient of variation (CV), in plasma samples ranges between 1.74 and 8.60% for STI-571 and 1.45 and 8.87% for N-DesM-STI. The corresponding values for urine measurements are 2.17-7.54% (STI-571) and 1.31-9.51% (N-DesM-STI). The inter-day precision analyzed over a 7-month time period was 8.31% (STI-571) or 6.88% (N-DesM-STI) and 16.45% (STI-571) or 14.83% (N-DesM-STI) for a concentration of 1000 ng/ml in plasma and 750 ng/ml in urine, respectively. Moreover, we demonstrate that with an alternative, but more time and labor consuming sample preparation and the implementation of electrochemical detection, a detection limit < 10 ng/ml can be achieved. The method described was used to perform pharmacokinetic measurements of STI-571 and N-desmethyl-STI in patient samples and for kinetic measurements of intracellular STI-571 and N-DesM-STI following in vitro incubation.

Purpose: In patients with acute leukemias, a lymphoid phenotype, the presence of a Philadelphia chromosome (Ph), and inadequate central nervous system (CNS)-directed prophylactic therapy are risk factors for CNS involvement. Imatinib mesylate has promising single-agent antileukemic activity in patients with advanced Ph(+) acute leukemias. It was the aim of this analysis to determine the incidence of, and risk factors associated with, meningeal leukemia during imatinib monotherapy., Study Design: We analyzed 107 consecutive patients with relapsed or refractory Ph(+) acute lymphoid leukemia (ALL; n = 65) or chronic myeloid leukemia blast crisis (n = 42) who were enrolled in successive Phase II trials of single-agent imatinib and who did not receive routine prophylactic intrathecal chemotherapy., Results: CNS leukemia developed in 13 of 107 patients (12%) and was associated primarily with a lymphoid or bilineage phenotype (12 of 78; 15%) and with imatinib refractory Ph(+) ALL (5 of 19; 26%). Meningeal leukemia did not occur among patients who received prior prophylactic cranial irradiation. The median survival with combined CNS and systemic disease was 108 days (range, 58-141), with no patient surviving long term. In contrast, two of three patients with exclusively meningeal leukemia achieved prolonged molecular remissions with intrathecal chemotherapy, cranial irradiation, and continued imatinib., Conclusions: Patients with Ph(+) ALL are at considerable risk of meningeal leukemia during imatinib monotherapy and should routinely receive CNS prophylaxis. Although the prognosis with combined meningeal and systemic relapse is dismal, patients with an isolated meningeal relapse may still achieve sustained remissions. The optimal type of CNS-directed treatment and the extent of protection afforded by prophylactic cranial irradiation remain to be defined.

The chronic myelogenous leukemia (CML)-like myeloproliferative disorder observed in the BCR/ABL murine bone marrow transduction and transplantation model shares several features with the human disease, including a high response rate to the tyrosine kinase inhibitor imatinib mesylate (STI571). To study the impact of chronic imatinib mesylate treatment on the CML-like illness, mice were maintained on therapeutic doses of this drug and serially monitored. Unexpectedly, despite excellent systemic control of the CML-like illness, many of the mice developed progressive neurologic deficits after 2 to 4 months of imatinib mesylate therapy because of central nervous system (CNS) leukemia. Analysis of imatinib mesylate cerebral spinal fluid concentrations revealed levels 155- fold lower than in plasma. Thus, in the mouse, the limited ability of imatinib mesylate to cross the blood-brain barrier allowed the CNS to become a sanctuary for Bcr/Abl-induced leukemia. This model will be a useful tool for the future study of novel anti-CML drugs and in better defining the mechanisms for limited imatinib mesylate penetration into the CNS.

The goals of the present study were to model the population kinetics of in vivo influx and efflux processes of grepafloxacin at the serum-cerebrospinal fluid (CSF) barrier and to propose a simulation-based approach to optimize the design of dose-finding trials in the meningitis rabbit model. Twenty-nine rabbits with pneumococcal meningitis receiving grepafloxacin at 15 mg/kg of body weight (intravenous administration at 0 h), 30 mg/kg (at 0 h), or 50 mg/kg twice (at 0 and 4 h) were studied. A three-compartment population pharmacokinetic model was fit to the data with the program NONMEM (Nonlinear Mixed Effects Modeling). Passive diffusion clearance (CL(diff)) and active efflux clearance (CL(active)) are transfer kinetic modeling parameters. Influx clearance is assumed to be equal to CL(diff), and efflux clearance is the sum of CL(diff), CL(active), and bulk flow clearance (CL(bulk)). The average influx clearance for the population was 0.0055 ml/min (interindividual variability, 17%). Passive diffusion clearance was greater in rabbits receiving grepafloxacin at 15 mg/kg than in those treated with higher doses (0.0088 versus 0.0034 ml/min). Assuming a CL(bulk) of 0.01 ml/min, CL(active) was estimated to be 0.017 ml/min (11%), and clearance by total efflux was estimated to be 0.032 ml/min. The population kinetic model allows not only to quantify in vivo efflux and influx mechanisms at the serum-CSF barrier but also to analyze the effects of different dose regimens on transfer kinetic parameters in the rabbit meningitis model. The modeling-based approach also provides a tool for the simulation and prediction of various outcomes in which researchers might be interested, which is of great potential in designing dose-finding trials.

A 32-year-old woman with relapsed Philadelphia chromosome-positive acute lymphoblastic leukaemia was treated with imatinib mesylate (formerly STI571), a selective inhibitor of BCR/ABL tyrosine kinase. Although the initial marrow response was good and stably maintained, she subsequently relapsed with extensive infiltration of leukaemic cells into the central nervous system (CNS). After controlling her CNS disease with additional intrathecal chemotherapy, we measured the concentration of imatinib in cerebrospinal fluid (CSF) and blood simultaneously. The concentration of imatinib in CSF was about 92-fold lower than that in blood. These results suggest that imatinib poorly penetrates the blood-brain barrier and has limited activity against CNS leukaemia.

We report a 53-year-old man with lymphoid blast crisis of Ph+ chronic myeloid leukaemia who was treated with STI571, a selective inhibitor of the enzymatic activity of BCR-ABL. He responded excellently to STI571 (600 mg/d), obtaining a complete cytogenetic remission after 3 months of therapy. Although remission in the bone marrow was sustained, the patient developed an isolated central nervous system relapse. Subsequent analyses of STI571 concentrations in the cerebrospinal fluid (CSF) revealed 2-log lower CSF levels of STI571 than corresponding plasma levels. These are the first data demonstrating a low penetration of orally administered STI571 into the CSF in humans.

Grepafloxacin, a new fluoroquinolone, produced bactericidal activity comparable to that of vancomycin and ceftriaxone in the treatment in rabbits of meningitis caused by a pneumococcal strain highly resistant to penicillin (MIC 4 mg/L) (triangle uplog(10) cfu/mL*h for grepafloxacin, -0.32 +/- 0.15; dose, 15 mg/kg iv; triangle uplog(10) cfu/mL*h for vancomycin, -0.39 +/- 0.18; dose, 2 x 20 mg/kg iv; triangle uplog(10) cfu/mL*h for ceftriaxone, -0.32 +/- 0. 12; dose, 125 mg/kg iv). Higher doses of grepafloxacin (30 mg/kg and 2 x 50 mg/kg) did not improve the killing rates. The combination of grepafloxacin with vancomycin was not significantly superior to monotherapies (P > 0.05). In vitro, grepafloxacin was bactericidal at concentrations above the MIC. Using concentrations around the MIC, addition of vancomycin to grepafloxacin showed synergic activity.

Oxidative damage due to free-radical generation in the setting of underlying defects of neuronal energy metabolism has been implicated as a pathogenetic mechanism for Huntington's disease (HD). The authors conducted a randomized, double-blind, placebo-controlled, multicenter trial of the tolerability of OPC-14117, a lipophilic free-radical scavenger that concentrates in the brain. Ambulatory patients with HD received OPC-14117 60 mg/d, 120 mg/d, 240 mg/d, or placebo and were assessed by the Unified Huntington's Disease Rating Scale (UHDRS) for 20 weeks, including 12 or 16 weeks of assigned treatment and 8 or 4 weeks of blinded withdrawal of the study drug. Tolerability was measured by the proportion of patients completing the initial 12-week course of treatment on their originally assigned regimen. Sixty-four patients were enrolled in the study, 56 of whom completed the 12 weeks of treatment. Treatment was discontinued in four patients (1 placebo, 1 60 mg/d, 2 240 mg/d) due to asymptomatic but persistent serum elevations of liver transaminase. Two patients (1 60 mg/d and 1 120 mg/d) withdrew because of increased involuntary movements, one patient (60 mg/d) withdrew due to persistent dry eyes, and one patient (120 mg/d) withdrew because of persistent vomiting. There were no significant differences between treatment arms in the primary measures of tolerability, the frequency and types of clinical adverse events, or the clinical/functional features of HD. OPC-14117 was safe and generally well tolerated; however, elevations of liver transaminase suggested that continued surveillance monitoring is warranted in conducting more long-term studies of this antioxidant therapy.

A sensitive reversed-phase high-performance liquid chromatographic method for the determination of atevirdine and its primary metabolite in human saliva or cerebrospinal fluid using solid-phase extraction is described. Samples mixed with internal standard and sodium phosphate buffer were applied to an activated C18 solid-phase extraction column. The reconstituted eluate was injected onto a Zorbax RX C8 column utilizing a mobile phase of 100 mM ammonium acetate (pH 4.0)-isopropyl alcohol-acetonitrile (55:20:25, v/v/v). Fluorescence detection was employed with excitation at 295 nm and emission at 456 nm. Quantitation was achieved using peak-height ratios. The detection response curve was linear from 2 to 850 nM for atevirdine in both human saliva and cerebrospinal fluid and from 2 to 250 nM for the metabolite in human saliva. The method was utilized to analyze cerebrospinal fluid and saliva samples from clinical studies.

The preferential absorption of certain drug compounds from the nasal cavity into the cerebrospinal fluid (CSF) raises questions regarding the transport processes controlling drug disposition following intranasal delivery. The disposition characteristics of several structurally similar antihistamine compounds, hydroxyzine, chlorpheniramine, triprolidine, and chlorcyclizine, into the CSF following nasal administration were studied using the rat as an animal model. The antihistamines were administered either intranasally or intra-arterially, and serial CSF and plasma samples were collected from the cisterna magna and the femoral artery, respectively. The drug levels in CSF and plasma were assayed by HPLC. Hydroxyzine concentrations in plasma and CSF were found to be significantly greater than most of the other compounds tested. In addition, hydroxyzine also showed the most rapid systemic absorption following nasal administration. Interestingly, the hydroxyzine levels in CSF following intranasal administration were significantly higher than those following intra-arterial administration. The AUC ratios between CSF and plasma for hydroxyzine after intranasal and intra-arterial administration were 4.0 and 0.4, respectively. The AUC ratios for triprolidine, the other antihistamine with measurable CSF concentrations, were 0.5 and 0.7, respectively. The distribution of antihistamines from the nasal membrane into the CSF appears to be controlled by a combination of their molecular properties. It also appears that the intranasal delivery of drugs with optimal physicochemical characteristics can result in an improved CNS bioavailability compared to those achieved from an equivalent parenteral dose.

Objectives: To determine the efficacy of the non-nucleoside reverse transcriptase inhibitor atevirdine in the treatment of AIDS dementia complex (ADC)., Design: Open label pilot study., Methods: Ten patients with ADC (stage 1 or 2) who were intolerant to zidovudine or dideoxyinosine, or in whom the antiretrovirals had failed to prevent further decline in CD4 cell levels, were entered into the study. Atevirdine, 1800 mg daily in three divided doses, was given over a 12-week period. Patients were assessed neurologically and neuropsychologically every 4 weeks. Cerebrospinal fluid analysis was performed at entry and at weeks 4 and 12. Technetium-99 exametazine single photon emission computed tomographic cerebral perfusion scans and magnetic resonance imaging brain scans were performed at weeks 0 and 12., Results: Five patients completed the 12 week protocol. Four of these five responded to atevirdine, as judged by quantified neurological and neuropsychological assessments. Atevirdine was well tolerated apart from the development of rash, anxiety, intermittent diarrhoea and fatigue., Conclusions: These preliminary results suggest that atevirdine is efficacious in the treatment of ADC. Larger blinded studies of this class of drug in the treatment of ADC are required.

The N-methyl-D-aspartate (NMDA) receptor complex plays a central role in the modulation of neuronal information in the central nervous system. This study was designed to examine the pharmacokinetics of the NMDA antagonist 3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid (CPP) in plasma and cerebrospinal fluid (CSF) and rostral spread in the CSF after lumbar intrathecal, extradural and i.v administration. Anaesthetized pigs were given a lumbar intrathecal, lumbar extradural or an i.v. injection of a mixture of [3H]-labelled and unlabelled CPP. CSF was sampled over 10 h through intrathecal catheters positioned at the L1, T5 and C1 vertebral levels. Blood samples were obtained over the same period. Haemodynamic and arterial blood-gas variables and acid-base balance were monitored during the study. The area under the radioactivity concentration-time curves showed a gradient between cervical and lumbar CSF radioactivity of about 1:2500 after intrathecal administration and about 1:140 after extradural administration, indicating that only small fractions of lumbar administered CPP spread rostrally. About 2% of an extradurally administered dose was found in the CSF. After i.v. administration of [3H]CPP, clearance was mean 122 (SEM 16) ml min-1 and the CSF: serum radioactivity gradient was approximately 1:4. The half-life of [3H]CPP varied little (mean range 94-191 min) irrespective of the route of administration or the level of sampling. Cervical radioactivity after lumbar intrathecal administration probably resulted from rostral transport via CSF bulk flow, whereas after extradural administration, systemic absorption and redistribution via the blood-brain barrier probably contributed.(ABSTRACT TRUNCATED AT 250 WORDS)

Objective: To determine the plasma and cerebrospinal fluid (CSF) levels of urapidil after i.v. administration and the effect on CSF serotonin and 5-hydroxyindoleacetic acid (5-HIAA) concentrations., Design: Open, single-dose study., Setting: Post-surgery following neurosurgical removal of the hypophysis (n = 5) or aneurysm clipping (n = 1)., Patients: 6 patients, aged 32-71 years, with intact blood-brain barrier (BBB); 1 patient was studied twice., Interventions: Single dose of 25 mg urapidil i.v. as prophylaxis of BP increase during extubation or as treatment of hypertensive episodes., Measurements and Results: Urapidil, serotonin and 5-HIAA were measured by HPLC in CSF during 8 h after urapidil administration. Urapidil was detected in CSF as soon as 5 min after injection in 3 patients. The concentration ratio of plasma/CSF after the distribution phase was about 5:1. No significant effect on serotonin and 5-HIAA in CSF was seen., Conclusion: After administration of a therapeutic dose, urapidil permeates the BBB and may interact with central 5-HT1A-receptors.

In order to examine the penetration of N-[4-[4-(diphenylmethyl)-1-piperazinyl]-butyl]-3-(6-methyl-3-pyrid yl) acrylamide (AL-3264, CAS 118420-47-6), a new antiallergic agent, into the brain, the antihistamine activities in the central and peripheral tissues from the rats and monkeys orally treated with AL-3264 were measured in comparison with those of ketotifen, oxatomide, mequitazine and terfenadine. These 5 drugs dose-relatedly suppressed the histamine-induced dye leakage in the rat skin and, except terfenadine, inhibited the binding of 3H-mepyramine to brain homogenates obtained from the rats treated orally with the drugs. The ratio (0.07) of AL-3264 for the central (3H-mepyramine binding) to peripheral (dye leakage) antihistamine activities was lower than that of ketotifen, oxatomide and mequitazine, and higher than that of terfenadine. The serum and cerebrospinal fluid (CSF) samples, which were collected from the monkeys treated with 80 mg/kg p.o. of AL-3264, terfenadine or oxatomide, inhibited the histamine-induced contractions in isolated guinea pig trachea. The ratio (0.003) of AL-3264 for the central (CSF) to peripheral (serum) antihistamine activities was lower than that of terfenadine and oxatomide. These results suggest that AL-3264 is poorly accessible to the brain, and may be regarded as a non-sedative antiallergic agent.

Cyclo(His-Pro) (CHP) is a peptide endogenous to human brain and cerebrospinal fluid (CSF). In animal studies administration of exogenous CHP augments dopaminergic neurotransmission. To explore the role of this peptide in schizophrenia, a disease characterized by a hyperdopaminergic state, we have measured CSF CHP levels in control, never-medicated schizophrenics and medicated schizophrenics. Our data show a 53% increase in CSF levels of CHP in never-medicated schizophrenics (p = 0.015), and a 25% increase in medicated schizophrenics when compared to controls. We speculate that CHP may contribute to the expression of hyperdopaminergic symptoms in schizophrenia.

In spinal cords from seven amyotrophic lateral sclerosis (ALS) patients and four controls, we found no difference in thyrotropin-releasing hormone (TRH) concentration relative to protein content, but there was a reduction per tissue wet weight in ALS. Immunohistochemical localization of TRH in ALS cord was unaltered. Histidyl proline diketopiperazine (HisPro-DKP), a possible metabolite of TRH, was significantly elevated per protein content in ALS. CSF levels of TRH and HisPro-DKP were unchanged. These findings suggest that TRH neurons are not primarily affected in ALS, but TRH and tissue protein are lost together as the disease progresses.

The distribution of cyclo(His-Pro), thyrotropin-releasing hormone and pyroglutamate aminopeptidase activity was examined in the CSF of human and a number of other mammalian species. Cyclo(His-Pro)-like immunoreactivity was present in the CSF of all species examined, and was immunologically and chromatographically identical with the authentic cyclo(His-Pro). Cyclo(His-Pro) concentration in CSF had no significant correlation with CSF TRH or pyroglutamate aminopeptidase.

In order to investigate a possible central nervous action of pirenzepine, an anti-ulcer drug with structural similarities to tricyclic psychotropic drugs, serum and cerebrospinal fluid concentrations of pirenzepine have been measured in five healthy volunteers after therapeutic dosage over 2.5 days. The cerebrospinal fluid:serum ratio was 0.095:1, indicating that pirenzepine passed the blood-brain barrier, but only to a small extent. The pirenzepine concentrations in the cerebrospinal fluid were for each volunteer on average about 10% of those found in serum. These findings correspond to the lack of central effects of pirenzepine as shown in animal and human experiments.

Levels of thyrotropin-releasing hormone (TRH) - and cyclo(His-Pro) (CHP)-like immunoreactivities and the activity of enzyme Pyroglutamate aminopeptidase (PAPase) were measured in cerebrospinal fluid (CSF) of over 100 normal adults (NA) and infants, and adult patients with various neurologic and neuropsychiatric disorders (NNDA). Levels of TRH and CHP in CSF of over 70% of the NA group were below 50 and 500 pg/ml respectively. The TRH- and CHP-like immunoreactivities in the remainder of the 30% of NA specimens exhibiting higher peptide concentrations were enzymatically and chromatographically characterized and were found to behave like authentic peptides. The levels of both of these peptides were significantly elevated in the CSF of most of the NNDA patients. An elevation in the CSF level of CHP was significantly correlated with the level of TRH, but not PAPase. Results from this study suggest that CSF elevation of TRH level may be due to a nonspecific response to stress that may be associated with hospitalization, myelogram procedure, and/or the neurologic and neuropsychiatric diseases for which the patients were admitted.

Razoxane (100 mg/kg) was administered to rats as a single IP dose. Plasma and CSF samples were obtained at intervals varying from 15 min to 24 h after dosing, and the razoxane was assayed by a new and simple high performance liquid chromatography (HPLC) technique. Razoxane was absorbed quickly from the peritoneal cavity; it reached a peak concentration within 0.5 h and decayed with a half-life of 1.6 h. Only 10% of the plasma razoxane available entered the CSF, reaching a peak concentration by 2h, which was maintained for a further 4 h, and finally decaying to reach 10% of its peak value by 8 h.

The pharmacology of ketoconazole was studied in patients with fungal infections. After administration of 50-, 100-, and 200-mg doses of ketoconazole, there was a linear increase in the area under the curve of serum concentrations; this was not apparent when higher doses of ketoconazole were given. An increase in the area under the curve occurred in patients receiving 200 mg daily who were restudied after 1 to 12 months of therapy. However, normalized area under the curve appeared to decrease after higher doses were administered chronically. The half life ranged from 2.0 to 3.3 h. Peak serum concentrations up to 50 micrograms/ml were detected in this study, and potentially therapeutic concentrations were detectable up to 26 h after high doses. Ketoconazole penetrated the saliva and inflamed joint fluid and meninges, although variably, and could be demonstrated in some other tissue compartments. In the presence of renal failure, ketoconazole disposition was not altered, whereas in the presence of hepatic insufficiency, an alteration in disposition was suggested. The interactions of ketoconazole and other drugs were studied. Of note, antacids did not significantly affect ketoconazole pharmacokinetics (nor did meals), and ketoconazole and warfarin did not appear to affect the pharmacokinetics of the other.

Ketoconazole is a broad-spectrum antifungal agent which appears promising for treatment of a variety of systemic mycoses. Pharmacokinetic studies are limited due to a lack of readily available methods for quantitation of ketoconazole in serum or cerebrospinal fluid. We developed a rapid, simple bioassay for measurement of ketoconazole alone or in the presence of therapeutic levels of amphotericin B, using an agar diffusion assay incorporating Candida pseudotropicalis. Pairs of 8-mm wells cut in the seeded assay medium were filled with four duplicate ketoconazole standards and duplicate patient specimens. Zones of inhibition were visible after 7 to 8 h of incubation, but were most easily measured after overnight growth. The assay allowed determinations of serum ketoconazole levels as low as 0.3 microgram/ml with a 4.4% coefficient of variation. Thirty-five serum samples from patients receiving the drug were assayed by this method, and the results were compared with the Coccidioides immitis endospore assay. The correlation coefficient between the assays was 0.90. This assay allows any microbiology laboratory to easily and safely determine ketoconazole levels in serum or cerebrospinal fluid.