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Aims: The safety, tolerability, pharmacokinetics (PK) and pharmacodynamics of single and multiple doses of a novel mGlu2 agonist were assessed in healthy males., Methods: In two, Phase 1 investigator- and subject-blind, placebo-controlled studies, oral doses of prodrug LY2979165 were evaluated: single doses (20-150 mg, N = 30) and multiple once-daily (QD) doses (20-400 mg; N = 84), using a titration regimen. The plasma and urine PK of LY2979165 and active moiety, 2812223, were measured. Cerebrospinal fluid (CSF) was collected to determine PK and neurotransmitter levels. Safety parameters were assessed throughout., Results: Nausea and vomiting were dose limiting following single doses; dose titration allowed higher doses to be tested over 14 days. The most common adverse events related to LY2979165 were dizziness, vomiting, nausea, somnolence and headache. The plasma PK of 2812223 were approximately linear with minimal accumulation with QD dosing. Conversion of LY2979165 to 2812223 was extensive, with minimal LY2979165 measurable in plasma. There was no effect of food on the PK of LY2979165 and 2812223. After 60 mg LY2979165 single-dose, 2812223 exposure in CSF was approximately 2-6% and plasma exposure and peak concentrations were approximately four-fold higher than the mGlu2 agonist in vitro EC 50 value. No consistent effects were observed on CSF neurotransmitter levels., Conclusions: Oral doses of LY2979165 up to 60 mg as a single dose and up to 400 mg given as multiple QD doses, using a titration regimen, were well tolerated with linear PK. Overall, these data support further clinical evaluation of LY2979165., (© 2017 The British Pharmacological Society.)

Interest in antifungal therapeutic-drug monitoring has increased due to studies demonstrating associations between concentrations and outcomes. We reviewed the antifungal drug concentration database at our institution to gain a better understanding of achievable triazole drug levels. Antifungal concentrations were measured by high-performance liquid chromatography (HPLC), ultraperformance liquid chromatography and single-quadrupole mass spectrometry (UPLC/MS), or a bioassay. For this study, only confirmed human bloodstream (serum or plasma) and cerebral spinal fluid (CSF) concentrations of voriconazole, posaconazole, and itraconazole were analyzed. The largest numbers of bloodstream and CSF samples were found for voriconazole (14,370 and 173, respectively). Voriconazole bloodstream concentrations within the range of 1 to 5.5 μg/ml represented 50.6% of samples. Levels below the lower limit of quantification (0.2 μg/ml) were observed in 14.6% of samples, and 10.4% of samples had levels of ≥5.5 μg/ml. CSF voriconazole levels ranged from undetectable to 15.3 μg/ml and were <0.2 μg/ml in 11% of samples. Posaconazole bloodstream concentrations were ≥0.7 and ≥1.25 μg/ml in 41.6% and 18.9% of samples, respectively. Posaconazole was detected in only 4 of 22 CSF samples (undetectable to 0.56 μg/ml). Itraconazole levels, as measured by UPLC/MS, were ≥0.5 μg/ml in 43.3% and were undetectable in 33.9% of bloodstream samples. In contrast, when measured by a bioassay, itraconazole/hydroxyitraconazole bloodstream concentrations were ≥1.0 μg/ml in 72.9% of samples and were undetectable in 18% of samples. These results indicate that there is marked variability in bloodstream concentrations achieved with these three azoles. In addition, many levels within the bloodstream for each azole and for voriconazole and posaconazole in the CSF were undetectable or below thresholds associated with efficacy.

To measure maraviroc total cerebrospinal fluid (CSF) concentrations and compare them with total and unbound plasma concentrations. Total maraviroc was measured by reverse-phase high-performance liquid chromatography with tandem mass spectrometry, whereas ultrafiltration was used for unbound maraviroc. Maraviroc was detected in all nine CSF/plasma pairs with a median CSF total concentration of 2.4 ng/ml. CSF concentrations exceeded the 50% inhibitory concentration of wild-type CC chemokine receptor 5-tropic HIV-1 in all specimens. CSF concentrations are lower than expected based on plasma concentrations and physicochemical characteristics. Unbound maraviroc plasma concentrations may be informative in estimating concentrations in CSF.

Objective: To determine maraviroc (MVC) concentrations in cerebrospinal fluid (CSF) in HIV-infected patients., Methods: Twelve CCR5+ HIV-1 adult antiretroviral-experienced patients receiving MVC-containing regimens for at least 1 month were enrolled. Both CSF and blood samples were taken around 12 hours after the last MVC dose. liquid chromatography tandem mass spectrometry was used to determine MVC concentrations, and HIV-1 viral load was determined by real-time polymerase chain reaction, (LOD, 40 copies/mL)., Results: Twelve blood and 12 CSF samples were collected. Median CD4 count was 281(120-759) cells per microliter, and median HIV-1 viral load was <40 copies per milliliter. Median time on MVC was 13.5 weeks (4-60). Nucleoside analogues (tenofovir/didanosine) were given in only 1 case. Median MVC concentrations in plasma were 124.75 (7.3-517) ng/mL. In all except one, CSF sample-receiving an erroneous MVC dose while taking concomitantly nevirapine-MVC concentrations [2.58 (<0.5-7.22) ng/mL] were within the EC(90) range (0.06-10.70). Median MVC CSF: plasma ratio was 0.022 (0.004-0.17), and when the free MVC plasma concentration was used, 0.094 (2.58-27.44). CSF viral load was <40 copies per milliliter in all 9 patients with undetectable plasma viral load., Conclusions: MVC achieves concentrations within the EC(90) range in CSF. All patients with undetectable plasma viral load although receiving nucleoside-sparing regimens including new drugs showed viral suppression in CSF.

In order to assess the penetration of maraviroc to the central nervous system, we measured maraviroc concentrations in cerebrospinal fluid (CSF) and plasma. Concentrations were determined by liquid chromatography tandem mass spectrometry (lower limit of quantitation 1.25 ng/ml) in seven paired CSF and plasma samples. The median plasma maraviroc concentration was 94.9 ng/ml (range 21.4-478.0) and the median CSF concentration was 3.63 ng/ml (range 1.83-12.2). CSF samples exceeded the median EC90 for maraviroc (0.57 ng/ml) by at least three-fold. The CSF levels of maraviroc found in this study likely contribute to viral suppression in the CSF.

For an adolescent with bacterial meningitis and subsequent cerebral aspergillosis, intravenous voriconazole dose requirements substantially decreased during coadministration with intravenous chloramphenicol and considerably rose after discontinuation of the antibiotic. In agreement with in vitro evidence, these data suggest that chloramphenicol is a rather significant inhibitor of hepatic CYP3A4 and/or CYP2C19.

We characterized voriconazole concentrations in the cerebrospinal fluid (CSF) of immunocompetent guinea pigs and patients with invasive fungal infections. In animals, after receipt of oral doses of 4 or 10 mg/kg every 8 h, the mean ratios of CSF to plasma total and free drug concentration were 0.68 and 1.3, respectively. In humans, 1-10 h after receipt of voriconazole, the CSF concentrations ranged from 0.08 to 3.93 microg/mL, and the ratio of CSF to plasma concentration ranged from 0.22 to 1.0 (median, 0.46).

We characterized the cerebrospinal fluid (CSF) penetration and pharmacokinetics of SCH-39304 in adult rhesus monkeys receiving a single oral dose of SCH-39304 (2.0 mg/kg of body weight). The mean CSF-to-plasma area under the curve ratio was 0.63 (+/- 0.18, standard error of the mean); maximum concentrations were 1.34 micrograms/ml (+/- 0.18) in CSF and 1.96 micrograms/ml (+/- 0.43) in plasma. The mean plasma half-life was 45.7 h (+/- 11), and mean CSF half-life was 38.7 h (+/- 3.5). The mean levels of SCH-39304 at 24 h were 1.48 micrograms/ml (+/- 0.3) in plasma and 0.96 microgram/ml (+/- 0.12) in CSF. We conclude that SCH-39304 effectively penetrates into CSF and achieves concentrations considered active against many opportunistic yeasts and that these concentrations are sustained in CSF for greater than or equal to 24 h.

We studied the penetration of three azole compounds, ketoconazole, itraconazole, and fluconazole, into the ocular tissues and fluids of rabbits in the presence and absence of ocular inflammation. Drug concentrations were compared with those found in serum and cerebrospinal fluid. The rank order of penetration into eye tissue was fluconazole greater than ketoconazole greater than itraconazole. Fluconazole penetrated freely into both inflamed and uninflamed eyes. The presence of inflammation improved penetration of all three compounds into ocular fluids and tissues. Penetration of these azoles into the anterior chamber of uninflamed eyes and into the cerebrospinal fluid was similar. All three azole compounds reduced the number of yeasts found in the eye in hematogenous Candida albicans endophthalmitis in rabbits when therapy was initiated within 24 h of inoculation. However, only ketoconazole significantly reduced yeast counts in the eye when therapy was postponed for 7 days.