Isavuconazole for treatment of refractory coccidioidal meningitis with concomitant cerebrospinal fluid and plasma therapeutic drug monitoring.

Coccidioidal meningitis (CM) is a life-threatening infection with limited treatment options. Small series have reported success with isavuconazole; however, limited data exist on cerebrospinal fluid (CSF) penetration. Paired plasma and CSF isavuconazole concentrations were measured. Eleven CSF levels were tested, (7 ventricular, 4 lumbar) in three CM patients. Ventricular CSF levels were undetectable despite detectable plasma levels. All lumbar CSF levels were detectable (mean 1.00 µg/ml). Three pairs of lumbar CSF/plasma concentrations taken within 1 h of each other yielded a mean CSF/plasma ratio of 0.31. Isavuconazole was detectable in lumbar but not ventricular CSF in three patients treated for refractory CM. LAY SUMMARY: Isavuconazole is a triazole antifungal that has been used as salvage therapy in the treatment of coccidioidal meningitis (CM). Few data exist characterizing its concentration in the cerebrospinal fluid (CSF). We report tandem plasma and CSF concentrations of isavuconazole in three patients with CM.

The Cerebrospinal Fluid Distribution of Postoperatively Administred Dexketoprofen and Etoricoxib and Their Effect on Pain and Inflammatory Markers in Patients Undergoing Hip Arthroplasty.

BACKGROUND AND OBJECTIVE: Based on earlier literature, etoricoxib may have a delayed analgesic effect in postoperative setting when analgesic efficacy of nonselective nonsteroidal anti-inflammatory drug dexketoprofen is rapid. This may be caused by slow penetration of etoricoxib into the central nervous system (CNS). Therefore we decided to determine the plasma and cerebrospinal fluid (CSF) pharmacokinetics and pharmacodynamics of dexketoprofen and etoricoxib in patients with hip arthroplasty. METHODS: A total of 24 patients, scheduled for an elective primary hip arthroplasty were enrolled. After surgery, 12 subjects were randomized to received a single intravenous dose of dexketoprofen, and 12 subjects were given oral etoricoxib. Paired blood and CSF samples were taken up to 24 h for measurement of drug concentrations, interleukin (IL)-6, IL-1ra and blood for interleukin 10. RESULTS: In CSF the highest measured concentration (C max) of dexketoprofen was 4.0 (median) ng/mL (minimum-maximum 1.9-13.9) and time to the highest concentration (t max) 3 h (2-5), and for etoricoxib C max 73 ng/mL (36-127) and t max 5 h (1-24), respectively. Opioid consumption during the first 24 postoperative hours was similar in the two groups. Dexketoprofen and etoricoxib had a similar effect on the postoperative inflammatory response. No significant differences considering pain relief or adverse events were found between the two groups. CONCLUSION: Dexketoprofen and etoricoxib entered the CNS readily, already at 30 min after administration dexketoprofen was detected in the CSF in most subjects and etoricoxib after 60 min. A single dose of dexketoprofen and etoricoxib provided a similar anti-inflammatory and analgesic response after major orthopaedic surgery.

Effect of protein binding on unbound atazanavir and darunavir cerebrospinal fluid concentrations.

HIV-1 protease inhibitors (PIs) exhibit different protein binding affinities and achieve variable plasma and tissue concentrations. Degree of plasma protein binding may impact central nervous system penetration. This cross-sectional study assessed cerebrospinal fluid (CSF) unbound PI concentrations, HIV-1 RNA, and neopterin levels in subjects receiving either ritonavir-boosted darunavir (DRV), 95% plasma protein bound, or atazanavir (ATV), 86% bound. Unbound PI trough concentrations were measured using rapid equilibrium dialysis and liquid chromatography/tandem mass spectrometry. Plasma and CSF HIV-1 RNA and neopterin were measured by Ampliprep/COBAS® Taqman® 2.0 assay (Roche) and enzyme-linked immunosorbent assay (ALPCO), respectively. CSF/plasma unbound drug concentration ratio was higher for ATV, 0.09 [95% confidence interval (CI) 0.06-0.12] than DRV, 0.04 (95%CI 0.03-0.06). Unbound CSF concentrations were lower than protein adjusted wild-type inhibitory concentration-50 (IC50 ) in all ATV and 1 DRV-treated subjects (P < 0.001). CSF HIV-1 RNA was detected in 2/15 ATV and 4/15 DRV subjects (P = 0.65). CSF neopterin levels were low and similar between arms. ATV relative to DRV had higher CSF/plasma unbound drug ratio. Low CSF HIV-1 RNA and neopterin suggest that both regimens resulted in CSF virologic suppression and controlled inflammation.

L-745,870 reduces L-DOPA-induced dyskinesia in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-lesioned macaque model of Parkinson's disease.

L-DOPA-induced dyskinesia remains an unmet challenge in the treatment of Parkinson's disease (PD). Here, we investigate the potential antidyskinetic efficacy of 3-([4-(4-chlorophenyl)piperazin-1-yl]methyl)-1H-pyrrolo[2,3-b]pyridine (L-745,870), a potent and selective dopamine D(4) receptor antagonist with a good toxicology profile and an excellent safety and tolerability record in phase I/II clinical studies, for non-PD indications. Six macaques were rendered parkinsonian by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine administration. After induction of stable and marked dyskinesia, animals were administered acute challenges of L-745,870 in combination with L-DOPA. To guarantee D(4) selectivity at the doses used in the study, we determined the plasma, cerebrospinal fluid, and brain levels of L-745,870. Coadministration of L-745,870 (1 mg/kg) and L-DOPA significantly reduced the severity of dyskinesia, by up to 59%, in comparison with L-DOPA alone (P < 0.01). L-745,870 had no effect on the duration of antiparkinsonian benefit (ON-time) (P > 0.05). However, L-745,870 (1 mg/kg) significantly increased the duration of ON-time without disabling dyskinesia (+204%; P < 0.001) and decreased duration of ON-time with disabling dyskinesia compared with L-DOPA alone (-56%; P < 0.01). Brain levels of L-745,870 (∼600 ng/g) were within the range at which L-745,870 provides selective D(4) receptor antagonism. Plasma levels were comparable with those demonstrated to be well tolerated in human studies. These data suggest that selective D(4) receptor antagonists represent a potential therapeutic approach for L-DOPA-induced dyskinesia. It is noteworthy that L-745,870 has already undergone significant clinical development, has an excellent profile for a therapeutic candidate, and could be advanced rapidly to phase IIa clinical studies for dyskinesia in PD.

The plasma and cerebrospinal fluid pharmacokinetics of sorafenib after intravenous administration in non-human primates.

PURPOSE: Sorafenib is a small molecule inhibitor of multiple signaling kinases thought to contribute to the pathogenesis of many tumors including brain tumors. Clinical trials with sorafenib in primary and metastatic brain tumors are ongoing. We evaluated the plasma and cerebrospinal fluid (CSF) pharmacokinetics (PK) of sorafenib after an intravenous (IV) dose in a non-human primate (NHP) model. METHODS: 7.3 mg/kg of sorafenib free base equivalent solubilized in 20% cyclodextrin was administered IV over 1 h to three adult rhesus monkeys. Serial paired plasma and CSF samples were collected over 24 h. Sorafenib was quantified with a validated HPLC/tandem mass spectrometry assay. PK parameters were estimated using non-compartmental methods. CSF penetration was calculated from the AUC(CSF) : AUC(plasma). RESULTS: Peak plasma concentrations after IV dosing ranged from 3.4 to 7.6 µg/mL. The mean ± standard deviation (SD) area under the plasma concentration from 0 to 24 h was 28 ± 4.3 µg • h/mL, which is comparable to the exposure observed in humans at recommended doses. The mean ± SD clearance was 1.7 ± 0.5 mL/min/kg. The peak CSF concentrations ranged from 0.00045 to 0.00058 µg/mL. The mean ± SD area under the CSF concentration from 0 to 24h was 0.0048 ± 0.0016 µg•h/mL. The mean CSF penetration of sorafenib was 0.02% and 3.4% after correcting for plasma protein binding. CONCLUSION: Sorafenib is well tolerated in NHP and measurable in CSF after an IV dose. The CSF penetration of sorafenib is limited relative to total and free drug exposure in plasma.

Absorption and distribution of etoricoxib in plasma, CSF, and wound tissue in patients following hip surgery--a pilot study.

The perioperative administration of selective cyclooxygenase-2 (COX-2)-inhibitors to avoid postoperative pain is an attractive option: they show favorable gastro-intestinal tolerability, lack inhibition of blood coagulation, and carry a low risk of asthmatic attacks. The purpose of this study was to determine the cerebrospinal fluid (CSF), plasma, and tissue pharmacokinetics of orally administered etoricoxib and to compare it with effect data, i.e., COX-2-inhibition in patients after hip surgery. The study was performed in a blinded, randomized, parallel group design. A total of 12 adult patients were included who received 120 mg etoricoxib (n = 8) or placebo (n = 4) on day 1 post-surgery. Samples from plasma, CSF, and tissue exudates were collected over a period of 24 h post-dosing and analyzed for etoricoxib and prostaglandin E(2) (PGE(2)) using liquid chromatography-tandem mass spectrometry and immuno-assay techniques. CSF area under the curve (AUC) [AUCs((O-24h))] for etoricoxib amounted to about 5% of the total AUC in plasma (range: 2-7%). Individual CSF lag times with respect to (50%) peak plasma concentration were

Low atazanavir concentrations in cerebrospinal fluid.

OBJECTIVE: Protease inhibitors may not penetrate into the central nervous system in therapeutic concentrations, which may allow ongoing HIV replication and injury. The objective of this study was to determine atazanavir penetration into cerebrospinal fluid (CSF). DESIGN: Single random plasma or paired plasma and CSF samples were drawn from participants enrolled in a multicenter, observational cohort study and taking atazanavir with or without ritonavir between October 2003 and October 2005. METHODS: Plasma samples were assayed by high performance liquid chromatography and immunoassay; lower limit of detection was 45 ng/ml. CSF samples were assayed by immunoassay (ARK ATV-test); lower limit of detection was 5 ng/ml. RESULTS: One hundred and seventeen participants (43 +/- 7.7 years, 79% men, 81 +/- 15 kg) had plasma or plasma and CSF paired samples drawn a median (interquartile range) of 10 (5-17) h postdose. Median (interquartile range) plasma atazanavir concentrations with or without ritonavir were 1278 (525-2265) and 523 (283-1344) ng/ml. The median (interquartile range) CSF concentrations with or without ritonavir were 10.3 (<5-21.1) and 7.9 (6.6-22) ng/ml. Nineteen of 79 (24%) CSF samples were less than 5 ng/ml. CSF concentrations were less than 1% of plasma concentrations and near the atazanavir wild-type IC50 of 1-11 ng/ml. CONCLUSION: Atazanavir CSF concentrations are highly variable and 100-fold lower than plasma concentrations, even with ritonavir boosting. CSF concentrations of atazanavir do not consistently exceed the wild-type IC50 of atazanavir and may not protect against HIV replication in the CSF.

Increased cerebrospinal fluid quinolinic acid, kynurenic acid, and L-kynurenine in acute septicemia.

Increases in brain quinolinic acid have been implicated in neurodegeneration and convulsions that may accompany infectious diseases. In three rhesus macaques (Macaca mulatta) with septicemia, both CSF and serum quinolinic acid concentrations were markedly elevated and were accompanied by increases in CSF kynurenic acid levels that were of a smaller magnitude. Elevated serum and CSF L-kynurenine concentrations also occurred and are consistent with activation of indoleamine-2,3-dioxygenase and increased substrate flux through the kynurenine pathway. Although it is probable that the marked increases in CSF quinolinic acid and kynurenic acid concentrations are reflected in the extracellular fluid space of brain, it remains to be determined whether the magnitude of such increases influences the activity of excitatory amino acid receptors in brain to produce excitotoxic pathology or noncytolytic disruption of functions mediated by excitatory amino acid receptors.

Increased ratio of quinolinic acid to kynurenic acid in cerebrospinal fluid of D retrovirus-infected rhesus macaques: relationship to clinical and viral status.

Increased concentrations of excitotoxin quinolinic acid in cerebrospinal fluid (CSF) are associated with infection with the human immunodeficiency virus (HIV-1) and have been implicated in the pathogenesis of the acquired immune deficiency syndrome (AIDS) dementia complex. In the present study, inoculation of macaques with D/1/California, an immunosuppressive serotype 1 type D retrovirus, was associated with acute and chronic increases in CSF and serum quinolinic acid concentrations in macaques that had developed SAIDS, a simian disease analogous to AIDS in humans--particularly macaques with demonstrable opportunistic infections. Kynurenic acid, an antagonist of excitatory amino acid receptors as well as the excitotoxic effects of quinolinic acid, was also increased in the CSF of SAIDS macaques, but to a significantly lesser degree than was quinolinic acid (kynurenic acid, 1.8-fold; quinolinic acid, 15.6-fold). CSF quinolinic acid, but not kynurenic acid, was also increased in viremic macaques with SAIDS-related complex (2.4-fold) and asymptomatic virus positive carriers (3.4-fold). Macaques that had recovered from D/1/California infection and were antibody positive and virus negative had normal CSF quinolinic acid and kynurenic acid concentrations. Increased activity of indoleamine-2,3-dioxygenase, the first enzyme of the kynurenine pathway, was indicated in the macaques with SAIDS by reduced serum L-tryptophan and elevated serum L-kynurenine concentrations. Macaques infected with D/1/California may provide a primate model for investigation of the mechanisms involved in increases in CSF quinolinic acid in retrovirus and other infectious diseases, including HIV-1. It remains to be determined whether the increased CSF quinolinic acid concentrations and the increased ratio of quinolinic acid to kynurenic acid have neurological significance or are a useful "marker" of infection.

Cerebrospinal fluid quinolinic acid concentrations are increased in acquired immune deficiency syndrome.

Dementia and brain atrophy are established features of a large proportion of patients with acquired immune deficiency syndrome (AIDS). To investigate a potential mechanism for atrophy in AIDS, we measured the concentration of the endogenous neurotoxin quinolinic acid in the cerebrospinal fluid of 10 patients with AIDS and found that they had 3-fold higher quinolinic acid concentrations than 9 age-matched control subjects: 53.8 +/- 10.7 pmol/ml versus 18.4 +/- 3.4 pmol/ml, respectively (p less than 0.005). It remains to be determined whether increased brain quinolinic acid concentrations are involved in the pathogenesis of the neuropathology of AIDS.

Cerebrospinal fluid levels of quinolinic acid in Huntington's disease and schizophrenia.

The concentration of the endogenous excitotoxin quinolinic acid was determined in the cerebrospinal fluid of drug-free patients suffering from Huntington's disease or schizophrenia (control group). In both diseases, quinolinic acid concentrations were highly variable (less than 4-48 nM) but the mean levels for each disease group were not significantly different from each other or from the quinolinic acid concentration of normal cerebrospinal fluid. Analysis of steady-state cerebrospinal fluid quinolinic acid concentration is unlikely to be of value as a diagnostic tool in Huntington's disease.