Plasma, Intracellular and Lymph node Antiretroviral Concentrations and HIV DNA Change During Primary HIV Infection: Results from the INACTION P25 Study

Despite its high effectiveness, combination antiretroviral treatment (cART) has a limited effect on HIV-DNA reservoir, which establishes early during primary infection (PHI) and is maintained by latency, homeostatic T-cells proliferation, and residual replication: this can be associated with low drug exposure in lymphoid tissues and/or suboptimal adherence to antiretroviral drugs (ARVs). Aim of this study was to assess ARVs concentrations in plasma, peripheral blood mononuclear cells (PBMC) and lymph nodes (LN), and their association to HIV-RNA and DNA decay during PHI. Participants were randomized to receive standard doses of darunavir/cobicistat (arm I), dolutegravir (arm II) or both (arm III), with a backbone of tenofovir alafenamide and emtricitabine. Total HIV-DNA was measured by digital-droplet PCR in PBMC at baseline, 12 and 48 weeks. Plasma and PBMC drugs concentrations were determined at 2, 12 and 48 weeks (LN at 12 weeks) by UHPLC-MS/MS. Seventy-two participants were enrolled, mostly male (n=68), median age 34 years and variable Fiebig stages (V-VI 57.7%, I-II 23.9%, and III-IV 18.3%). Twenty-six patients were assigned to Arm I, 27 to Arm II and 19 to Arm III. After 48 weeks, most patients had undetectable viremia, with minor between-arms differences in HIV-RNA decay. Patients with Fiebig I-II showed faster HIV-RNA and HIV-DNA decay. Intracellular-tissue penetration was high for nucleoside analogues and low-moderate for darunavir and dolutegravir. Only tenofovir diphosphate concentrations in PBMC showed correlation with HIV-DNA decay. Overall, this study suggests the timing of treatment initiation and intracellular tenofovir penetration as primary and secondary factors affecting HIV reservoir.

Pharmacokinetics and Safety of Twice-daily Ritonavir-boosted Atazanavir With Rifampicin

BACKGROUND

Critical drug-drug interactions (DDI) and hepatotoxicity complicate concurrent use of rifampicin and protease inhibitors. We investigated whether dose escalation of atazanavir/ritonavir could safely overcome the DDI with rifampicin.

METHODS

DERIVE (NCT04121195, EDCTP) was a dose-escalation trial in people with human immunodeficiency virus (HIV) on atazanavir/ritonavir-based antiretroviral therapy (ART) in Uganda. Four intensive pharmacokinetic (PK) visits were performed: PK1 300/100 mg OD (baseline); PK2 300/100 mg OD with rifampicin 600 mg; PK3 300/100 mg twice a day (BID) with rifampicin 600 mg OD; PK4 300/100 mg BID with rifampicin 1200 mg OD. Dolutegravir 50 mg BID throughout the study period ensured participants remained protected from subtherapeutic atazanavir concentrations. The data were interpreted with noncompartmental analysis. The target minimum concentration was atazanavir's protein-adjusted IC90 (PA-IC90), 0.014 mg/L.

RESULTS

We enrolled 26 participants (23 female) with median (range) age 44 (28-61) years and weight 67 (50-75) kg. Compared with PK1, atazanavir Ctau, and AUC were significantly reduced at PK2 by 96% and 85%, respectively. The escalation to BID dosing (PK3) reduced this difference in Ctau, and AUC24 to 18% lower and 8% higher, respectively. Comparable exposures were maintained with double doses of rifampicin. Lowest Ctau during PK1, PK3, and PK4 were 12.7-, 4.8-, and 8.6-fold higher than PA-IC90, respectively, whereas 65% of PK2 Ctau were below the limit of quantification (0.03 mg/L), hence likely below PA-IC90. No participant developed significant elevation of liver enzymes, reported a serious adverse event (SAE) or experienced rebound viraemia.

CONCLUSIONS

Twice daily atazanavir/ritonavir during rifampicin co-administration was well tolerated and achieved plasma concentrations above the target.

CLINICAL TRIALS REGISTRATION

NCT04121195. Registered on 09 October 2019, https://clinicaltrials.gov/ct2/show/NCT04121195.

Cannabinoid levels description in a cohort of patients with chronic and neuropathic pain treated with Cannabis decoction: A possible role of TDM

The phytocomplex of Cannabis is made up of approximately 500 substances: terpeno-phenols metabolites, including Δ-9-tetrahydrocannabinol and cannabidiol, exhibit pharmacological activity. Medical Cannabis has several pharmacological potential applications, in particular in the management of chronic and neuropathic pain. In the literature, a few data are available concerning cannabis pharmacokinetics, efficacy and safety. Thus, aim of the present study was the evaluation of cannabinoid pharmacokinetics in a cohort of patients, with chronic and neuropathic pain, treated with inhaled medical cannabis and decoction, as a galenic preparation. In this study, 67 patients were enrolled. Dried flower tops with different THC and CBD concentrations were used: Bedrocan® medical cannabis with THC level standardized at 19% and with a CBD level below 1%, Bediol® medical cannabis with THC and CBD level standardized at similar concentration of 6.5% and 8%, respectively. Cannabis was administered as a decoction in 47 patients and inhaled in 11 patients. The blood withdrawn was obtained before the new dose administration at the steady state and metabolites plasma concentrations were measured with an UHPLC-MS/MS method. Statistically significant differences were found in cannabinoids plasma exposure between inhaled and oral administration of medical cannabis, between male and female and cigarette smokers. For the first time, differences in cannabinoid metabolites exposures between different galenic formulations were suggested in patients. Therapeutic drug monitoring could be useful to allow for dose adjustment, but further studies in larger cohorts of patients are required in order to confirm these data.

Comparative Performance Assessment of Novel Fluorescence Immunoassay POCTs for Measuring Circulating Levels of Vitamin-D

Vitamin D (Vit D) is a fat-soluble molecule acting like a hormone, and it is involved in several biological mechanisms such as gene expression, calcium homeostasis, bone metabolism, immune modulation, viral protection, and neuromuscular functions. Vit D deficiency can lead to chronic hypocalcemia, hyperparathyroidism, and many other pathological conditions; in this context, low and very low levels of 25-hydroxy-vitamin D (25-OH-D) were found to be associated with an increased risk of COVID-19 infection and the likelihood of many severe diseases. For all these reasons, it is important to quantify and monitor 25-OH-D levels to ensure that the serum/blood concentrations are not clinically suboptimal. Serum concentration of 25-OH-D is currently the main indicator of Vit D status, and it is currently performed by different assays, but the most common quantitation techniques involve immunometric methods or chromatography. Nevertheless, other quantitation techniques and instruments are now emerging, such as AFIAS-1® and AFIAS-10® (Boditech and Menarini) based on the immunofluorescence analyzer, that guarantee an automated system with cartridges able to give quick and reliable results as a point-of-care test (POCT). This work aims to compare AFIAS-1® and AFIAS-10® (Boditech and Menarini) Vit D quantitation with Ultra High-Performance Liquid Chromatography coupled with tandem mass spectrometry that currently represents the gold standard technique for Vit D quantitation. The analyses were performed in parallel on 56 samples and in different conditions (from fresh and frozen plasma) to assess the reliability of the results. Any statistically significant differences in methods, the fixed error, and the error proportional to concentration were reported. Results obtained in all conditions showed a good correlation between both AFIAS® instruments and LC-MS/MS, and we can affirm that AFIAS-1® and AFIAS-10® are reliable instruments for measuring 25-OH-D with accuracy and in a fast manner.

Pharmacokinetics of tecovirimat in subjects with Mpox

OBJECTIVE

To investigate the pharmacokinetics (PK) of tecovirimat in subjects with Mpox.

METHODS

This monocentric, prospective, observational study enrolled subjects with Mpox who received standard treatment with oral tecovirimat. Plasma samples for PK assessment were collected at steady state (5-8 days after initiation of antiviral therapy), before and 3, 5, 7 and 12 h after tecovirimat administration. Drug concentrations were determined by validated liquid chromatography coupled with tandem mass spectrometry. PK parameters were calculated using Phoenix 8.1.

RESULTS

Overall, 14 male patients hospitalized for severe Mpox with ongoing tecovirimat treatment were enrolled in this study. Six of the 14 patients were living with human immunodeficiency virus (HIV), all of whom were on antiretroviral therapy (ART) and virologically suppressed at the time of hospitalization. Significant differences in tecovirimat PK were observed in subjects without HIV compared with subjects with HIV. In subjects with HIV, the maximum tecovirimat plasma concentration (39%, P≤0.0001), minimum tecovirimat plasma concentration (42%, P=0.0079) and area under the curve from zero to the last measured time-point (40%, P≤0.0001) were significantly lower compared with subjects without HIV, but all concentrations remained above the in-vitro calculated 90% inhibitory concentration. No significant associations were found between demographic/clinical data and tecovirimat PK. All patients recovered completely within 14 (range 6-36) days of treatment initiation.

CONCLUSIONS

This study found a significant decrease in plasma exposure of tecovirimat in Mpox patients with HIV on effective ART compared with those without HIV, with no evident impact on clinical outcomes. Although these results need to be confirmed in larger studies, they may provide useful information on the PK of tecovirimat.

Stability Study of Fosfomycin in Elastomeric Pumps at 4 °C and 34 °C: Technical Bases for a Continuous Infusion Use for Outpatient Parenteral Antibiotic Therapy

BACKGROUND

Fosfomycin acts against aerobic Gram-/+ bacteria by blocking the synthesis of peptidoglycan. Its use has been currently re-evaluated for intravenous administration for the treatment of systemic infections by multidrug-resistant bacteria. Concentration-/time-dependent activity has been suggested, with potential clinical advantages from prolonged or continuous infusion. Nevertheless, little is known about Fosfomycin stability in elastomeric pumps. The aim of the present work was stability investigation before administration at 4 °C and during administration at 34 °C.

METHODS

InfectoFos® (InfectoPharm s.r.l., Milan, Italy) preparation for intravenous use in elastomeric pumps at 4 °C and 34 °C was analyzed following EMA guidelines for drug stability. Samples were analyzed with an ultra-high performance liquid chromatography coupled with tandem mass spectrometry method on a LX50® UHPLC system equipped with a QSight 220® (Perkin Elmer, Milan, Italy) tandem mass spectrometer.

RESULTS

Fosfomycin in elastomeric preparation is stable for at least 5 days at a storage temperature of 4 °C and 34 °C.

CONCLUSIONS

The results suggest Fosfomycin eligibility for continuous infusion even in the context of outpatient parenteral antibiotic therapy. Therefore, this approach should be tested in clinical and pharmacokinetic studies, in order to evaluate the possible gains in the pharmacokinetic profile and the clinical effectiveness.

Vitamin D impact in affecting clozapine plasma exposure: A potential contribution of seasonality

Schizophrenia affects approximately 24 million people worldwide and clozapine is the most effective antipsychotic drug. Nevertheless, its use in therapy is limited due to adverse effects.Therapeutic drug monitoring is a clinical tool useful to reduce the clozapine toxicity. In the literature, papers showed how psychiatric disorders could be associated with low vitamin D levels, but a few studies focusing on its role in affecting clozapine exposure are available. A TDM repository was analyzed: clozapine and vitamin D levels measured with liquid chromatography were considered. 1261 samples obtained from 228 individuals were evaluated: 624 patients (49.5%) showed clozapine plasma levels in therapeutic range (350-600 ng/mL). Clozapine toxic plasma levels (>1000 ng/mL) were more present in winter (p = 0.025), compared to other seasons. Concerning vitamin D, a sub-analysis of 859 samples was performed: 326 (37.81%) were deficient ( ng/mL), 490 (57.12%) had insufficient concentrations (10-30 ng/mL), while 43 (5.02%) had sufficient (>30 ng/mL) levels. A correlation between vitamin D and clozapine plasma levels (p = 0.007, Pearson coefficient=0.093) was observed. The role of seasonal variation in clozapine plasma exposure in psychiatric patients treated with clozapine was suggested. Further studies in larger cohorts are needed in order to clarify these aspects.

Real-Life Experience of Continuously Infused Ceftolozane/Tazobactam in Patients with Bronchiectasis and Multidrug-Resistant Pseudomonas aeruginosa Infection in the Outpatient Setting

(1) Background: Ceftolozane/tazobactam (C/T) is a novel β-lactam/β-lactamase inhibitor with excellent activity against the multidrug-resistant (MDR) P. aeruginosa. Continuous infusion (CI) dosing allows the optimization of pharmacokinetic and pharmacodynamic (PK/PD) properties of β-lactam antibiotics and may support patients' treatment as outpatients. (2) Methods: Adult patients receiving their entire course of C/T as a CI in the outpatient setting were retrospectively included in the study. The primary outcome evaluated was clinical resolution. The secondary outcomes evaluated were PK/PD target attainment (ƒT > 4 × MIC) and microbiologic clearance at the end of treatment. Therapeutic drug monitoring to assess C/T concentration was performed. (3) Results: Three patients were enrolled in the study and received 9 g of C/T in CI every 24 h. One patient received an additional course of antimicrobial therapy due to disease exacerbation six months after initial treatment, accounting for four evaluated treatments. The primary outcome was achieved in 3/4 treatments and the secondary outcome was achieved in 4/4 and 3/3, respectively. In all patients, free ceftolozane concentrations were >10 times higher than the EUCAST breakpoint (4 mg/L). (4) Conclusions: Elastomeric infusion of C/T delivered in CI can be an effective and convenient way to treat acute diseases caused by MDR-P. aeruginosa, avoid hospital admission, and contribute to infection control strategies. Despite the small number of enrolled patients, clinical and microbiological results support this strategy.

Development and In-House Validation of an Enzyme-Linked Immunosorbent Assay and a Lateral Flow Immunoassay for the Dosage of Tenofovir in Human Saliva

Highly active antiretroviral therapy (HAART) includes very potent drugs that are often characterized by high toxicity. Tenofovir (TFV) is a widely used drug prescribed mainly for pre-exposure prophylaxis (PreP) and the treatment of human immunodeficiency virus (HIV). The therapeutic range of TFV is narrow, and adverse effects occur with both underdose and overdose. The main factor contributing to therapeutic failure is the improper management of TFV, which may be caused by low compliance or patient variability. An important tool to prevent inappropriate administration is therapeutic drug monitoring (TDM) of compliance-relevant concentrations (ARCs) of TFV. TDM is performed routinely using time-consuming and expensive chromatographic methods coupled with mass spectrometry. Immunoassays, such as enzyme-linked immunosorbent assays (ELISAs) and lateral flow immunoassays (LFIAs), are based on antibody-antigen specific recognition and represent key tools for real-time quantitative and qualitative screening for point-of-care testing (POCT). Since saliva is a non-invasive and non-infectious biological sample, it is well-suited for TDM. However, saliva is expected to have a very low ARC for TFV, so tests with high sensitivity are required. Here, we have developed and validated a highly sensitive ELISA (IC50 1.2 ng/mL, dynamic range 0.4-10 ng/mL) that allows the quantification of TFV in saliva at ARCs and an extremely sensitive LFIA (visual LOD 0.5 ng/mL) that is able to distinguish between optimal and suboptimal ARCs of TFV in untreated saliva.

A Novel UHPLC-MS/MS Method for the Quantification of Seven Opioids in Different Human Tissues

BACKGROUND

Opioids are considered the cornerstone of pain management: they show good efficacy as a first-line therapy for moderate to severe cancer pain. Since pharmacokinetic/pharmacodynamic information about the tissue-specific effect and toxicity of opioids is still scarce, their quantification in post-mortem autoptic specimens could give interesting insights.

METHODS

We describe an ultra-high-performance liquid chromatography coupled with tandem mass spectrometry method for the simultaneous quantification of methadone, morphine, oxycodone, hydrocodone, oxymorphone, hydromorphone and fentanyl in several tissues: liver, brain, kidney, abdominal adipose tissue, lung and blood plasma. The presented method has been applied on 28 autoptic samples from different organs obtained from four deceased PLWH who used opioids for palliative care during terminal disease.

RESULTS

Sample preparation was based on tissue weighing, disruption, sonication with drug extraction medium and a protein precipitation protocol. The extracts were then dried, reconstituted and injected onto the LX50 QSight 220 (Perkin Elmer, Milan, Italy) system. Separation was obtained by a 7 min gradient run at 40 °C with a Kinetex Biphenyl 2.6 µm, 2.1 × 100 mm. Concerning the analyzed samples, higher opioids concentrations were observed in tissues than in plasma. Particularly, O-MOR and O-COD showed higher concentrations in kidney and liver than other tissues (>15-20 times greater) and blood plasma (>100 times greater).

CONCLUSIONS

Results in terms of linearity, accuracy, precision, recovery and matrix effect fitted the recommendations of FDA and EMA guidelines, and the sensitivity was high enough to allow successful application on human autoptic specimens from an ethically approved clinical study, confirming its eligibility for post-mortem pharmacological/toxicological studies.

Analytical validation of a novel UHPLC-MS/MS method for 19 antibiotics quantification in plasma: Implementation in a LC-MS/MS Kit

BACKGROUND

Therapeutic drug monitoring (TDM) for antibiotic drugs represents a consolidated practice to optimize the effectiveness and to limit the toxicity of specific drugs by guiding dosage adjustments. The comparison of TDM results with drug-specific pharmacokinetic/pharmacodynamic (PK/PD) parameters, based on killing dynamics and bacterial susceptibility, increases the probability of therapeutic success.

PURPOSE

The aim of this study was the analytical validation of a new UHPLC-MS/MS assay for the quantification of 19 antibiotics divided in two different sets considering their chemical/pharmacological properties. This method has been implemented in an analytical LC-MS/MS Kit System by CoQua Lab s.r.l (Turin).

METHODS

The analytical validation is developed in accordance with "ICH Harmonized Guideline M10 on bioanalytical method validation and study sample analysis" and "Guidelines for regulatory auditing of quality management system of medical device manufacturers". Method suitability in the clinical context was tested by analysing clinical samples from patients treated with antibiotic drugs.

RESULTS

This method allows for simultaneous TDM of the following molecules: dalbavancin, daptomycin, linezolid, tedizolid, levofloxacin, moxifloxacin, meropenem, ertapenem, vaborbactam, avibactam, sulbactam, tazobactam, ceftazidime, ceftriaxone, ceftolozane, ceftobiprole, cefiderocol, ceftaroline and piperacillin. These drugs were quantified showing analytical performance parameters compliant with guidelines in terms of repeatability, reproducibility, robustness, bias, LOD, LOQ and linearity. The method was capable to successfully monitor drug concentrations in 65 samples from 52 patients undergoing treatment.

CONCLUSION

The UHPLC-MS/MS method described in this work can be useful for TDM of the reported antimicrobial agents. The analytical protocol is rapid and suitable to be used in routine analysis.

Inflammation and intracellular exposure of dolutegravir, darunavir, tenofovir and emtricitabine in people living with HIV

AIMS

Antiretroviral (ARV) therapy reduces inflammation and immune activation in people with HIV, but not down to the levels observed in people without HIV. Limited drug penetration within tissues has been argued as a potential mechanism of persistent inflammation. Data on the inflammation role on ARV plasma/intracellular (IC) pharmacokinetics (PK) through to expression of cytochrome P450 3A/membrane transporters are limited. The aim of this study was to investigate the correlation between inflammation markers (IM) and plasma/IC PK of ARV regimen in HIV-positive patients.

METHODS

We included ART-experienced patients switching to three different ARV regimens. Plasma and IC ARV drug concentration means at the end of dosing interval (T₀ ), IM on samples concomitantly with ARV PK determination: sCD14, CRP, IL-6 and LPS were analysed.

RESULTS

Plasma and IC drug concentrations were measured in 60 samples. No significative differences between CRP, sCD14, IL-6 and LPS values in the three arms were observed. A significant inverse correlation between tenofovir plasma concentration and sCD14 (rho = -0.79, P < .001), and between DRV IC/plasma ratio and Log₁₀ IL-6 concentrations (rho = -0.36, P = .040), and a borderline statistically significant positive trend between DRV plasma concentration and sCD14 (rho = 0.31, P = .070) were suggested. Furthermore, a borderline statistically significant inverse trend between DTG IC concentrations and sCD14 (rho = -0.34, P = .090) was observed in 24 patients on DTG-based triple therapy.

CONCLUSIONS

Our preliminary data support the hypothesis of lower DRV and DTG IC concentrations and lower TFV plasma exposure in patients with higher plasma IM suggesting an interplay between HIV drug penetration and persistent inflammation in cART-treated HIV-positive patients.

Possible Impact of Vitamin D Status and Supplementation on SARS-CoV-2 Infection Risk and COVID-19 Symptoms in a Cohort of Patients with Inflammatory Bowel Disease

The coronavirus disease (COVID-19) pandemic represents a global health challenge, particularly considering concomitant diseases. Patients with inflammatory bowel diseases (IBD) can be considered a population at risk. On the other hand, the risk of developing IBD and COVID-19 have both been described as modulated by vitamin D (VD) levels. In this work, a cohort of 106 adult patients affected by IBD was prospectively enrolled, during the second wave of the pandemic in Italy. In these patients, VD plasma levels, demographic, and clinical characteristics were tested for a correlation/an association with the risk of infection with SARS-CoV-2 in the study period (anti-spike IgG positivity) and the severity of COVID-19 symptoms. By multivariate logistic regression analysis, VD supplementation (Odds Ratio; OR 0.116, p = 0.002), therapy with monoclonal antibodies (OR 0.227, p = 0.007), and the use of mesalazine (OR 2.968, p = 0.046) were found to be independent predictors of SARS-CoV-2 positivity. Moreover, hypertension was associated with severe disease (p = 0.019), while a VD level higher than 30 ng/mL (p = 0.031, OR 0.078) was associated with asymptomatic infection. No interplay between IBD activity and COVID-19 risk of infection or symptoms was observed. These results confirm the importance of VD levels in defining the risk of COVID-19 and give encouraging data about the safety of maintaining immunomodulatory treatments for IBD during the COVID-19 pandemic.

Pharmacokinetic of Cefiderocol in Critically Ill Patients Receiving Renal Replacement Therapy: A Case Series

Background: Cefiderocol is a novel parenteral siderophore cephalosporin, demonstrating enhanced activity against multidrug-resistant (MDR) Gram-negative bacteria and difficult-to-treat Acinetobacter baumannii (DTR-AB). Plasma-free trough concentration (fCtrough) over the minimum inhibitory concentration (MIC) was reported as the best pharmacokinetic parameter to describe the microbiological efficacy of cefiderocol. Materials and methods: We retrospectively described the pharmacokinetic and pharmacodynamic profile of three critically ill patients admitted to the intensive care unit, receiving cefiderocol under compassionate use to treat severe DTR-AB infections while undergoing continuous venovenous haemofiltration. Cefiderocol was administrated at a dosage of 2 g every 8 h infused over 3 h. Therapeutic drug monitoring (TDM) was assessed at the steady state. Cthrough was evaluated by assuming a plasma protein binding of 58.0%. The fCmin/MIC was calculated assuming a cefiderocol MIC equal to the PK-PD breakpoint of susceptibility ≤ 2. The association between the PK/PD parameters and microbiological outcome was assessed. Results: fCtrough/MIC were >12 in 2 patients and 2.9 in the 1 who rapidly recovered from renal failure. Microbiological cure occurred in 3/3 of patients. None of the 3 patients died within 30 days. Conclusions: A cefiderocol dosage of 2 g q8 h in critically ill patients with AKI undergoing CVVH may bring about a very high plasma concentration, corresponding to essentially 100% free time over the MIC for DTR-AB.

A description of Cannabinoid levels in Cannabis oil by high-performance liquid chromatography-mass spectrometry in a reference laboratory of North-Italy

BACKGROUND

Cannabis oils from FM2®, Bedica®, Bediol®, Bedrocan®, Bedrolite® and Pedanios 22/1® are largely used for medical purposes such as spasticity, chronic pain and appetite stimulating. Several studies showed cannabinoids action on CB1 and CB2 receptors reduces the hyperalgesic phase in inflammatory pain, leading to an improvement of conditions. The active compounds of these galenic preparations show a high variability making titration mandatory. For this reason, the exact oil composition knowledge is fundamental for personalizing therapy. This amis at adapting the correct dose to the patient, improving safety and efficacy of the galenic formulation, choosing the best preparation for each patient.

PURPOSE

The aim of this study was to investigate oil preparations variability among different galenic laboratories in order to highlight the importance of titration activity.

METHODS

Cannabis pharmacological active compounds titration has been performed in a large cohort of galenic laboratories in Italy. CBD, CBN, THC, THCA and CBDA quantification was carried out by a previous validated method in UHPLC-MS/MS.

RESULTS

A number of 4318 samples of Cannabis oil from 83 pharmacies between January 2021 and February 2022 were evaluated. All galenic preparation specialities showed statistically significant differences among galenic laboratories (p-value < 0.001). THCA and CBDA concentrations were investigated as percentage of the extration yelds for total THC and CBD: these compounds had different values in the same specialities among distinct galenic laboratories. Moreover, seasonal variability in analytes concentrations was observed.

CONCLUSION

This study described a wide range of oily samples from a large number of galenic laboratories, compared to published papers. In conclusion, knowledge of the exact oil composition is fundamental in the perspective of personalized therapy. Further studies aiming at the correlation between galenic composition and cannabinoids pharmacokinetics, clinical outcomes and toxic effects could be useful to improve our knowledge.

Ceftobiprole and daptomycin concentrations in valve tissue in a patient with mitralic native valve endocarditis

Ceftobiprole (CFB), especially in combination, could be a promising alternative treatment for infective endocarditis. A main determinant of clinical response to antibiotic treatment is drug concentration at the infected site. Data on CFB and Daptomycin (DPT) heart valve penetration are lacking.Here we report a clinical case of CFB and DPT treatment combination for endocarditis. Then, we measured CFB and DPT concentrations in a native infected valve to verify their pharmacokinetic penetration and relationship with pharmacodynamic microbiological markers.The isolated microorganism was a MRSA with CFB and DPT MIC < 2 mg/L and <1 mg/L, respectively. The CFB and DPT plasma concentrations were 36.2 and 14.1 mg/L, respectively and the extrapolated concentration, based on each half-life, at the operatory time were 16.4 and 19.1 mg/L for CFB and DPT, respectively; the corresponding median CFB and DPT valve concentrations were 2.26 (IQR 2.14-2.69) and 12.9 µg/g (IQR 5.69-20.9), respectively; the estimated tissue/plasma ratios for CFB and DTP were 0.14 and 0.67, respectively.The association of CFB and DPT showed a good efficacy in this single endocarditis clinical case, confirmed by plasma and tissue PK/PD data.This report shows the first data on CFB valve tissue penetration, and it needs to be confirmed in other patient valve tissues. Moreover, relative studies of correlation with clinical efficacy are needed.

Monthly Increase in Vitamin D Levels upon Supplementation with 2000 IU/Day in Healthy Volunteers: Result from "Integriamoci", a Pilot Pharmacokinetic Study

Vitamin D (VD) is a calcium- and phosphate-controlling hormone used to treat bone disorders; yet, several other effects are progressively emerging. VD deficiency is highly prevalent worldwide, with suboptimal exposure to sunlight listed among the leading causes: oral supplementation with either cholecalciferol or calcitriol is used. However, there is a scarcity of clinical studies investigating how quickly VD concentrations can increase after supplementation. In this pilot study, the commercial supplement ImmuD3 (by Erboristeria Magentina^®) was chosen as the source of VD and 2000 IU/day was administered for one month to 21 healthy volunteers that had not taken any other VD supplements in the previous 30 days. Plasma VD levels were measured through liquid chromatography coupled to tandem mass spectrometry after 7, 14, and 28 days of supplementation. We found that 95% of the participants had insufficient VD levels at baseline (<30 ng/mL; median 23.72 ng/mL; IQR 18.10–26.15), but after 28 days of supplementation, this percentage dropped to 62% (median 28.35 ng/mL; IQR 25.78–35.20). The median increase in VD level was 3.09 ng/mL (IQR 1.60–5.68) after 7 days and 8.85 ng/mL (IQR 2.85–13.97F) after 28 days. This study suggests the need for continuing VD supplementation and for measuring target level attainment.

A Non-Invasive Method for Detection of Antihypertensive Drugs in Biological Fluids: The Salivary Therapeutic Drug Monitoring

Objectives: Arterial hypertension is still the most frequent cause of cardiovascular and cerebrovascular morbidity and mortality. Antihypertensive treatment has proved effective in reduction of cardiovascular risk. Nevertheless, lifestyle interventions and pharmacological therapy in some cases are ineffective in reaching blood pressure target values, despite full dose and poly-pharmacological treatment. Poor adherence to medications is an important cause of treatment failure. Different methods to assess therapeutic adherence are currently available: Therapeutic drug monitoring in biological fluids has previously demonstrated its efficacy and reliability. Plasma and urine have been already used for this purpose, but they may be affected by some practical limitations. Saliva may represent a feasible alternative.

Methods: Fourteen antihypertensive drugs and two metabolites were simultaneously tested in plasma, urine, and saliva. Tested molecules included: atenolol, nebivolol, clonidine, ramipril, olmesartan, telmisartan, valsartan, amlodipine, nifedipine, doxazosin, chlorthalidone, hydrochlorothiazide, indapamide, sacubitril, ramiprilat, and sacubitrilat. Therapeutic drug monitoring was performed using ultra-high performance liquid chromatography, coupled to tandem mass spectrometry (UHPLC-MS/MS). The method has been preliminarily evaluated in a cohort of hypertensive patients.

Results: The method has been validated according to US Food and Drug Administration (FDA) and European Medicines Agency (EMA) guidelines. The application on a cohort of 32 hypertensive patients has demonstrated sensibility and specificity of 98% and 98.1%, respectively, with a good feasibility in real-life clinical practice.

Conclusion: Saliva may represent a feasible biological sample for therapeutic drug monitoring by non-invasive collection, prompt availability, and potential accessibility also in out-of-clinic settings.

Monitoring Tacrolimus Concentrations in Whole Blood and Peripheral Blood Mononuclear Cells: Inter- and Intra-Patient Variability in a Cohort of Pediatric Patients

Tacrolimus (TAC) is a first-choice immunosuppressant for solid organ transplantation, characterized by high potential for drug-drug interactions, significant inter- and intra-patient variability, and narrow therapeutic index. Therapeutic drug monitoring (TDM) of TAC concentrations in whole blood (WB) is capable of reducing the incidence of adverse events. Since TAC acts within lymphocytes, its monitoring in peripheral blood mononuclear cells (PBMC) may represent a valid future alternative for TDM. Nevertheless, TAC intracellular concentrations and their variability are poorly described, particularly in the pediatric context. Therefore, our aim was describing TAC concentrations in WB and PBMC and their variability in a cohort of pediatric patients undergoing constant immunosuppressive maintenance therapy, after liver transplantation. TAC intra-PBMCs quantification was performed through a validated UHPLC–MS/MS assay over a period of 2–3 months. There were 27 patients included in this study. No significant TAC changes in intracellular concentrations were observed (p = 0.710), with a median percent change of −0.1% (IQR −22.4%–+46.9%) between timings: this intra-individual variability was similar to the one in WB, −2.9% (IQR −29.4–+42.1; p = 0.902). Among different patients, TAC weight-adjusted dose and age appeared to be significant predictors of TAC concentrations in WB and PBMC. Intra-individual seasonal variation of TAC concentrations in WB, but not in PBMC, have been observed. These data show that the intra-individual variability in TAC intracellular exposure is comparable to the one observed in WB. This opens the way for further studies aiming at the identification of therapeutic ranges for TAC intra-PBMC concentrations.

Seasonal Variation of Antiretroviral Drug Exposure during the Year: The Experience of 10 Years of Therapeutic Drug Monitoring

Although studies show an annual trend for immunosuppressive drugs, particularly during different seasons, no data are available for antiretroviral drugs exposures in different periods of the year. For this reason, the aim of this study was to investigate an association between seasonality and antiretroviral drugs plasma concentrations. Antiretroviral drugs exposures were measured with liquid chromatography validated methods. A total of 4148 human samples were analysed. Lopinavir, etravirine and maraviroc levels showed seasonal fluctuation. In detail, maraviroc and etravirine concentrations decreased further in summer than in winter. In contrast, lopinavir concentrations had an opposite trend, increasing more in summer than in winter. The etravirine efficacy cut-off value of 300 ng/mL seems to be affected by seasonality: 77.1% and 22.9% of samples achieved this therapeutic target, respectively, in winter and summer, whereas 30% in winter and 70% in summer did not reach this value. Finally, age over 50 years and summer remained in the final multivariate regression model as predictors of the etravirine efficacy cut-off. This study highlights the seasonal variation in antiretroviral drugs plasma concentrations during the year, leading to a better understanding of inter-individual variability in drug exposures. Studies are required in order to confirm these data, clarifying which aspects may be involved.

Real-life study on the pharmacokinetic of remdesivir in ICU patients admitted for severe COVID-19 pneumonia

Remdesivir is one of the most encouraging treatments against SARS‐CoV‐2 infection. After intravenous infusion, RDV is rapidly metabolized (t_1/2 = 1 h) within the cells to its active adenosine triphosphate analogue form (GS‐443902) and then it can be found in plasma in its nucleoside analogue form (GS‐441524). In this real‐life study, we describe the remdesivir and GS‐441524 concentrations at three time points in nine ICU patients, through a validated ultra‐high‐performance liquid chromatography tandem mass spectrometry (UHPLC–MS/MS) method. The observed data confirmed the very rapid conversion of RDV to its metabolite and the quite long half‐life of GS‐441524. The mean C_min, C_max and AUC_0–24, were < 0.24 ng/mL and 122.3 ng/mL, 2637.3 ng/mL and 157.8 ng/mL, and 5171.2 ng*h/mL and 3676.5 ng*h/ml, respectively, for RDV and GS‐441524. Three out of nine patients achieved a C_max > 2610 ng/mL and 140 ng/mL and AUC_0–24 > 1560 ng*h/mL and 2230 ng*h/mL for RDV and GS‐441524, respectively. The mean t_1/2 value for GS‐441524 was 26.3 h. Despite the low number of patients, these data can represent an interesting preliminary report on the variability of RDV and GS‐441524 concentrations in a real‐life ICU setting.

Analytical Validation and Clinical Application of Rapid Serological Tests for SARS-CoV-2 Suitable for Large-Scale Screening

Recently, large-scale screening for COVID-19 has presented a major challenge, limiting timely countermeasures. Therefore, the application of suitable rapid serological tests could provide useful information, however, little evidence regarding their robustness is currently available. In this work, we evaluated and compared the analytical performance of a rapid lateral-flow test (LFA) and a fast semiquantitative fluorescent immunoassay (FIA) for anti-nucleocapsid (anti-NC) antibodies, with the reverse transcriptase real-time PCR assay as the reference. In 222 patients, LFA showed poor sensitivity (55.9%) within two weeks from PCR, while later testing was more reliable (sensitivity of 85.7% and specificity of 93.1%). Moreover, in a subset of 100 patients, FIA showed high sensitivity (89.1%) and specificity (94.1%) after two weeks from PCR. The coupled application for the screening of 183 patients showed satisfactory concordance (K = 0.858). In conclusion, rapid serological tests were largely not useful for early diagnosis, but they showed good performance in later stages of infection. These could be useful for back-tracing and/or to identify potentially immune subjects.

Observed concentrations of amikacin and gentamycin in the setting of burn patients with gram-negative bacterial infections: Preliminary data from a prospective study

AIM OF THE STUDY

Critically ill populations often have shown subtherapeutic aminoglycosides' concentrations mostly because of unavoidable changes in drug volume distribution and clearance. We present a real life prospective study evaluating plasma concentrations for once-daily dosing for amikacin and gentamycin among a population of severe burn adults.

METHODS

We conducted a real life prospective study on the plasma observed concentrations of amikacin and gentamycin among severe burn patients, using aminoglycoside as combination therapy. Antibiotics were prescribed at the standard doses of 15-20mg/kg/day for amikacin and 3-5mg/kg/day for gentamycin.

RESULTS

Eight patients (4 in amikacin and 4 in gentamycin groups, respectively) were enrolled in the study. All subjects were admitted for severe burns. The most common site of infection was bloodstream (5; 62.5%) and pneumonia (4; 50%). Pseudomonas aeruginosa, followed by Klebsiella pneumoniae and multi-drug resistant Acinetobacter baumannii were the most prevalent agents isolated. Amikacin and gentamycin never achieved the target peak concentration of 60mg/L and 30mg/L: in our study C_max, for amikacin, was 33.1±15.6mg/L (SD), while for gentamycin was 14.3mg/L±9. C_max and total body surface area have shown a strong negative correlation with borderline statistical significance (amikacin: ρ=0.922, P=0.078; gentamycin: ρ=0.937, P=0.063). At the standard dosage, the pharmacokinetic/pharmacodynamic (PK/PD) target of C_max>8×highest MIC was reached for 8 (53.3%) out of 15 isolated pathogens.

CONCLUSIONS

The present study found that, in a population of septic burn patients, standard doses of gentamycin and amikacin most often lead to plasma concentrations under the PK/PD target.

Lack of concordance between EMIT assay and LC-MS/MS for Therapeutic Drug Monitoring of Mycophenolic Acid: Potential increased risk for graft rejection?

Therapeutic drug monitoring (TDM) of immunosuppressive drugs is crucial in organ-transplanted patients to prevent rejection or toxic effects due to inadequate dosage. Mycophenolic acid (MPA) is a commonly used immunosuppressant in this setting. Nowadays, MPA concentrations are monitored by Enzyme Multiplied Immunoassay Technology (EMIT), and Liquid Chromatography (LC)-based techniques, particularly coupled to Tandem Mass Spectrometry (LC-MS/MS). This study evaluates the concordance between TDM results for MPA obtained through CE-IVD EMIT and LC-MS/MS assays in plasma samples. LC-MS/MS quantification was based on a commercial kit and the analytical performance in terms of accuracy was tested through external proficiency tests and inter-laboratory comparison with a home-made HPLC-UV method. Both these evaluations confirmed the reliability of the LC-MS/MS method (1.6 % and 9.0 % of bias, respectively). Conversely, the comparison between EMIT and LC-MS/MS showed overestimation by EMIT of 33.5 %. This bias resulted concentration-dependent, ranging from 46.4 % in the concentration range of 1-2 mg/L, to 21.4 % over 4 mg/L. Considering the theoretical clinical impact of this overestimation, a fraction comprised between 12.4 % and 31.4 % of samples which resulted over three different minimum effective concentration values by EMIT (no indication for dose adjustment) had discordant indications by LC-MS/MS (dose adjustment needed). Concluding, this study highlights a clinically relevant systematic overestimation of MPA concentration by EMIT, supporting the switch to LC-MS/MS techniques for TDM purpose. However, further prospective studies are needed in order to evaluate the clinical impact of switching the TDM activity from EMIT to LC-MS/MS in a larger cohort in a long period.

Daptomycin Plasma and CSF Levels in Patients with Healthcare-Associated Meningitis

BACKGROUND

There are currently few data concerning the cerebrospinal fluid (CSF) penetration of daptomycin in patients with healthcare-associated meningitis. This study aims (1) to better characterize the pharmacokinetics of daptomycin in humans during a 7-day intravenous (IV) therapy course, and (2) to study the penetration of daptomycin in the CSF after IV infusion at the dose of 10 mg/kg.

RESULTS

In this prospective observational study, we enrolled nine patients with an implanted external ventricular drainage and a diagnosis of a healthcare-associated meningitis. Daptomycin was administered at 10 mg/kg for a maximum of 7 days. The pharmacokinetic of daptomycin was studied using a two-compartment population/pharmacokinetic (POP/PK) model and by means of a nonlinear mixed effects modeling approach. A large inter-individual variability in plasma area under the curve (Range: 574.7-1366.3 h mg/L), paralleled by high-peak plasma concentration (C_max) (all values > 60 mg/L), was noted. The inter-individual variability of CSF-AUC although significant (range: 1.17-6.81 h mg/L) was narrower than previously reported and with a late occurrence of CSF-C_max (range: 6.04-9.54 h). The terminal half-life between plasma and CSF was similar. t_max values in CSF did not show a high inter-individual variability, and the fluctuations of predicted CSF concentrations were minimal. The mean value for daptomycin penetration obtained from our model was 0.45%.

CONCLUSIONS

Our POP/PK model was able to describe the pharmacokinetics of daptomycin in both plasma and CSF, showing that daptomycin (up to 7 days at 10 mg/kg) has minimal penetration into central nervous system. Furthermore, the observed variability of AUC, t_max and predicted concentration in CSF was lower than what previously reported in the literature. Based on the present findings, it is unlikely that daptomycin could reach CSF concentrations high enough to have clinical efficacy; this should be tested in future studies.

25-Hydroxyvitamin D Concentrations Are Lower in Patients with Positive PCR for SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), with a clinical outcome ranging from mild to severe, including death. To date, it is unclear why some patients develop severe symptoms. Many authors have suggested the involvement of vitamin D in reducing the risk of infections; thus, we retrospectively investigated the 25-hydroxyvitamin D (25(OH)D) concentrations in plasma obtained from a cohort of patients from Switzerland. In this cohort, significantly lower 25(OH)D levels (p = 0.004) were found in PCR-positive for SARS-CoV-2 (median value 11.1 ng/mL) patients compared with negative patients (24.6 ng/mL); this was also confirmed by stratifying patients according to age >70 years. On the basis of this preliminary observation, vitamin D supplementation might be a useful measure to reduce the risk of infection. Randomized controlled trials and large population studies should be conducted to evaluate these recommendations and to confirm our preliminary observation.

Correlation between entecavir penetration in peripheral blood mononuclear cells and HBV DNA decay during treatment of HBeAg-negative chronic hepatitis B

BACKGROUND

Recently, due to its high effectiveness and tolerability, the treatment of chronic hepatitis B with entecavir became a standard practice. However, limited knowledge is currently available about its pharmacokinetic behaviour and intracellular disposition. Recently, our group reported an inverse correlation between entecavir plasma concentrations and the HBV DNA decay at the first and third month of treatment, respectively. In this paper we investigated the penetration of entecavir in peripheral blood mononuclear cells (PBMC) and in plasma, in order to evaluate the relationship between intracellular penetration and response, in a cohort of naive patients with hepatitis B e antigen (HBeAg)-negative CHB.

METHODS

Thirty-three patients were prospectively enrolled and gave written informed consent: the monitoring of clinical parameters (for example, HBV DNA, hepatitis B surface antigen [HBsAg], alanine aminotransferase) was carried out at the baseline and then monthly. Entecavir intra-PBMC and plasma trough concentrations were measured at 1 month of treatment, through a validated method based on liquid chromatography coupled with tandem mass spectrometry.

RESULTS

While plasma entecavir analysis confirmed previous evidence of inverse correlation between drug concentrations and HBV DNA decrease after 3 months of treatment (r=-0.723; P<0.001), this correlation was not significant for intra-PBMC concentrations. When the intracellular disposition ratio (intra-PBMC/plasma concentration ratio) was considered, it showed a direct and significant correlation with HBV DNA decay at the third month (r=0.485; P=0.004).

CONCLUSIONS

These results suggest that the antiviral activity of entecavir is dependent on its intracellular uptake, thus resulting in lower plasma concentrations in patients who have a marked HBV DNA decrease during treatment.

Pharmacogenetics of the anti-HCV drug sofosbuvir: a preliminary study

Background

Sofosbuvir is a potent nucleotide HCV NS5B polymerase inhibitor that is also a P-glycoprotein (encoded by the ABCB1 gene) and breast cancer resistance protein (encoded by the ABCG2 gene) substrate. Concerning previous anti-HCV therapies, pharmacogenetics had a significant impact, particularly considering the association of interleukin28B polymorphisms with dual-therapy (ribavirin + pegylated IFN) outcomes.

Objectives

In this work, we investigated the association between sofosbuvir and its prevalent metabolite (GS-331007) plasma concentrations at 1 month of therapy and genetic variants (SNPs) in genes encoding transporters and nuclear factors (ABCB1, ABCG2 and HNF4α) related to sofosbuvir transport.

Patients and methods

Allelic discrimination was performed through real-time PCR, whereas plasma concentrations were evaluated through liquid chromatography. One hundred and thirteen patients were enrolled.

Results

Sofosbuvir concentrations were below the limit of quantification since the drug was converted into its GS-331007 metabolite. ABCB1 2677 G>T (P = 0.044) and HNF4α 975 C>G (P = 0.049) SNPs were associated with GS-331007 metabolite plasma concentrations. In linear multivariate analysis, liver stiffness, insulin resistance, baseline haemoglobin and haematocrit and SNPs in the ABCB1 gene (3435 CT/TT and 1236 TT genotypes) were significant predictors of GS-331007 concentrations. Furthermore, we performed sub-analyses considering the anti-HCV concomitant drug and HCV genotype, identifying specific polymorphisms associated with GS-331007 plasma concentrations: ABCB1 3435 C>T and HNF4α975 C>G in patients treated with daclatasvir, ABCB1 2677 G>T with ledipasvir and ABCB1 3435 C>T, ABCB1 2677 G>T, ABCG2 421 C>A and ABCG2 1194 + 928 C>A with ribavirin.

Conclusions

In this study we suggested sofosbuvir GS-331007 metabolite plasma levels were affected by variants in the ABCB1 and HNFα genes.

Therapeutic drug monitoring-guided definition of adherence profiles in resistant hypertension and identification of predictors of poor adherence

AIMS

Arterial hypertension is an important cardiovascular risk factor. A substantial proportion of patients show resistance to antihypertensive treatment but poor adherence to medication regimens is also a significant cause of treatment failure. In this context, therapeutic drug monitoring (TDM) could be useful. The objective of this study was to assess adherence to treatment in patients with resistant hypertension by TDM and to identify parameters that predict nonadherence.

METHODS

Liquid chromatography tandem mass spectrometry was used to quantify a wide panel of antihypertensive drugs in human plasma to assess treatment compliance. Associations between TDM-determined adherence profiles, self-reported adherence and other patient-related clinical, anthropometric or demographic features were evaluated as potentially useful pre-TDM predictors of poor adherence.

RESULTS

TDM was performed on 50 patients with suspected resistant hypertension: 24% of patients partially complied to treatment and 18% were nonadherent. No concordance was observed with questionnaire results, while nonadherence was associated with high diastolic blood pressure, high heart rate, previous onset of stroke and previous use of invasive treatments, including renal denervation or baroreceptor stimulation.

CONCLUSIONS

This evidence highlights the high prevalence of poor adherence in patients with resistant hypertension and the need for caution in using invasive approaches. These preliminary data require validation in a larger cohort, to confirm the need for TDM in routine clinical practice.

Pharmacogenetic of voriconazole antifungal agent in pediatric patients

AIM

We explored the role of SNPs within the SLCO1B3, SLCO1B1, SLC22A6, ABCB1, ABCG2, SLCO3A1, CYP2C19, ABCC2, SLC22A1, ABCB11 and NR1I2 genes on voriconazole pharmacokinetics.

PATIENTS & METHODS

233 pediatric patients were enrolled. Drug plasma C_trough was measured by a HPLC-MS method. Allelic discrimination was performed by qualitative real-time PCR.

RESULTS

SLCO1B3 rs4149117 c.334 GT/TT (p = 0.046), ABCG2 rs13120400 c.1194 + 928 CC (p = 0.029) and ABCC2 rs717620 c.-24 GA/AA (p = 0.025) genotype groups significantly influenced C_trough. ethnicity (p = 0.042), sex (p = 0.033), SLCO1B3 rs4149117 c.334 GT/TT (p = 0.041) and ABCB1 rs1045642 c.3435 TT (p = 0.016) have been retained in linear regression model as voriconazole predictor factors.

CONCLUSION

Understanding how some gene polymorphisms affect the voriconazole pharmacokinetic is essential to optimally dose this agent.

Influence of ABCB11 and HNF4α genes on daclatasvir plasma concentration: preliminary pharmacogenetic data from the Kineti-C study

Background

Daclatasvir is an inhibitor of HCV non-structural 5A protein and is a P-glycoprotein substrate. Pharmacogenetics has had a great impact on previous anti-HCV therapies, particularly considering the association of IL-28B polymorphisms with dual therapy outcome.

Objectives

We investigated the association between daclatasvir plasma concentrations at 2 weeks and 1 month of therapy and genetic variants (SNPs) in genes encoding transporters and nuclear factors (ABCB1, ABCB11 and HNF4α).

Patients and methods

Allelic discrimination was achieved through real-time PCR, whereas plasma concentrations were evaluated through LC-MS/MS.

Results

Fifty-two patients were analysed, all enrolled in the Kineti-C study. HNF4α 975 C > G polymorphism was found to be associated with the daclatasvir plasma concentrations at 2 weeks (P = 0.009) and 1 month of therapy (P = 0.006). Linear regression analysis suggested that, at 2 weeks of therapy, age, baseline BMI and haematocrit were significant predictors of daclatasvir concentrations, whereas at 1 month of therapy ABCB111131 CC and HNF4α CG/GG genotypes were significant predictors of daclatasvir concentrations.

Conclusions

These are the first and preliminary results from our clinical study focusing on daclatasvir pharmacogenetics, showing that this approach could have a role in the era of new anti-HCV therapies.

Effect of ABCC2 and ABCG2 Gene Polymorphisms and CSF-to-Serum Albumin Ratio on Ceftriaxone Plasma and Cerebrospinal Fluid Concentrations

We measured ceftriaxone pharmacokinetics in patients' plasma and cerebrospinal fluid (CSF) and assessed the influence of biometric, demographic, genetic (ABCB1, ABCC2, ABCB11, ABCG2, and SLCO1A2 polymorphisms) and pathological features. Adult patients with signs and symptoms of central nervous system infections, receiving intravenous ceftriaxone, were enrolled. Ceftriaxone plasma and CSF concentrations were measured by high-precision liquid chromatographic methods; allelic discrimination was performed by real-time polymerase chain reaction. Forty-three patients were included: median ceftriaxone maximal concentration was 15,713 ng/mL in plasma and 3512 ng/mL in CSF with a CSF-to-plasma ratio of 0.3. ABCC2 1249 rs2273697 (P = .027) and ABCG2 1194+928 rs13120400 (P = .015) variants were significantly associated with CSF concentrations and CSF-to-plasma ratios. At linear regression analysis, CSF-to-serum albumin ratio was an independent predictor of ceftriaxone CSF concentrations (P = .001; also in those with intact blood-brain barrier: P = .031) and CSF-to-plasma ratio (P = .001; also in those with blood-brain barrier impairment: P = .040). We here report the role of transporters' genetic variants as well as of blood-brain barrier permeability in predicting ceftriaxone exposure in the central nervous system.

Vitamin D pathway gene polymorphisms affecting daclatasvir plasma concentration at 2 weeks and 1 month of therapy

AIM

Vitamin D (VD) influences genetic expression through its receptor (VDR). VD pathway gene polymorphisms seem to influence antiviral drug pharmacokinetics and therapeutic outcome/toxicity. We investigated the association between daclatasvir (DCV) plasma concentrations and genetic variants (SNPs) associated with the VD pathway.

PATIENTS & METHODS

Chronic hepatitis C patients treated with DCV from 2014 to 2016 were included. Genotypes were assessed through real-time PCR and plasma concentrations through liquid chromatography.

RESULTS

A total of 52 patients were analyzed. DCV levels were influenced by CYP24A1 rs2248359T>C polymorphism at 2 weeks and VDR Cdx2 A>G at 1 month of treatment. Linear regression analysis showed baseline BMI, alanine aminotransferase and hematocrit as significant predictors of DCV concentrations at 2 weeks, BMI and hematocrit at baseline, VDR Cdx2 AG/GG and FokI TC/CC at 1 month.

CONCLUSION

These results showed a possible role of VD pathway gene polymorphisms in influencing DCV plasma concentrations, but further studies are required.

Vitamin D pathway genetic variants are able to influence sofosbuvir and its main metabolite pharmacokinetics in HCV mono-infected patients

Vitamin D levels and genetic variants were associated with drug outcome/toxicity and concentrations. The plasma exposure of GS-331007, the main sofosbuvir metabolite, has been related to SVR. We evaluated the impact of polymorphisms in genes (CYP27B1, CYP24A1, VDBP and VDR) related to vitamin D pathway on sofosbuvir and GS-331007 plasma levels in HCV mono-infected patients at one month of treatment. Polymorphisms were investigated through real-time PCR; drug plasma quantification was performed through a UHPLC-MS/MS method. GS-331007 levels were associated with CYP24A1rs2248359 and VDRCdx2 variants in all the analyzed patients and linear regression analysis showed that sex, body mass index, HCV genotype, baseline estimated glomerular filtration rate, VDRCdx2AG/GG and CYP27B1-1260TT genotypes significantly predict concentrations. We performed sub-analyses considering the HCV genotype and the concomitant drug, identifying polymorphisms associated with GS-331007 concentrations. This is the first study focusing on vitamin D pathway gene variants and DAAs concentrations, but further studies are required.

Precision medicine for HIV: where are we?

To date, antiretroviral therapy is highly effective in HIV-affected patients, but the individualization of such a life-long therapy may be advised. This review briefly summarizes the main factors involved in the potential personalization of antiretroviral treatment. Relevant articles in English were identified by PubMed and recent congresses’ abstracts. Foremost influences concerning pharmacodynamics, therapeutic drug monitoring, pharmacogenetics, comorbidities, immune recovery and viral characteristics affecting the healthcare of HIV-positive patients are listed here. Furthermore, pharmacoeconomic aspects are mentioned. Applying pharmacokinetic and pharmacogenetic knowledge may be informative and guide the better choice of treatment in order to achieve long-term efficacy and avoid adverse events. Randomized investigations of the clinical relevance of tailored antiretroviral regimens are needed in order to obtain a better management of HIV/AIDS-affected patients.

Daclatasvir Plasma Levels in a Cohort of Patients with Hepatitis C Virus Infection Taking Methadone: A Prospective Analysis

Backround: The effect of methadone (MET) during therapy with novel direct-acting antiviral agents is still not fully understood. Currently, no data are available about the influence of MET on daclatasvir (DCV) plasma levels in patients affected by chronic hepatitis C (CHC). The aim of this study was to assess the DCV plasma concentrations in patients treated with sofosbuvir (SOF) plus DCV, with or without ribavirin (RBV) and with or without MET.

METHODS

In this analysis, 47 patients were included, treated consecutively with SOF + DCV ± RBV for 24 weeks, from May to October 2015; 22 (46.8%) received MET substitutive therapy.

RESULTS AND CONCLUSION

We found a significant difference in DCV levels at 2 weeks and 1 month: 150 ng/mL in patients without MET and 313 ng/mL with MET at 2 weeks (p < 0.001), 149 and 279 ng/mL at 1 month (p = 0.006). DCV levels were lower in cirrhotic patients (p < 0.001); among cirrhotic patients we also evidenced higher DCV concentrations in patients receiving MET at 2 weeks, 1 and 2 months (p < 0.001, p = 0.005, and p = 0.031, respectively). In multivariate analysis, the only predictive factor associated with DCV plasma levels was the presence of MET. The reason for this increased DCV exposure is unclear; on the clinical side, we have not observed significant adverse events related to the reduction or increase of MET plasma levels. The administration of MET in patients with advanced fibrosis or cirrhosis leads to an early increase of DCV plasma level without significant clinical effects or toxicity.

Cannabinoids concentration variability in cannabis olive oil galenic preparations

OBJECTIVES

Knowledge of the exact concentration of active compounds in galenic preparations is crucial to be able to ensure their quality and to properly administer the prescribed dose. Currently, the need for titration of extracts is still debated. Considering this, together with the absence of a standard preparation method, the aim of this study was to evaluate cannabinoids concentrations variability in galenic olive oil extracts, to evaluate the interlot and interlaboratory variability in the extraction yield and in the preparation composition.

METHODS

Two hundred and one extracts (123 (61.2%) from Bedrocan^® , 54 (26.9%) from Bediol^® , 11 (5.5%) from Bedrolite^® , and 13 (6.5%) from mixed preparations) were analysed by liquid chromatography coupled with tandem mass spectrometry, quantifying cannabinoids (THC, CBD, THCA, CBDA and CBN) concentrations.

KEY FINDINGS

The RSD% of THC and CBD concentrations resulted higher than 50%. Specifically for Bedrocan^® , Bediol^® , Bedrolite^® (5 g/50 ml), these were THC 82%, THC 53% and CBD 91%, THC 58% and CBD 59%, respectively. The median extraction yields were greater than 75% for all preparations.

CONCLUSIONS

Our results highlighted a wide variability in THC and CBD concentrations that justify the need for titration and opens further questions about other pharmaceutical preparations without regulatory indication for this procedure.

Therapeutic drug monitoring of voriconazole for treatment and prophylaxis of invasive fungal infection in children

Voriconazole therapeutic drug monitoring is not consistently recommended due to its high interpatient and intrapatient variability. Here, we aimed to describe our experience with voriconazole for treatment and prophylaxis of invasive fungal infections in paediatric patients. A fully validated high-performance liquid chromatography-mass spectrometry method was used to quantify voriconazole concentration in plasma, at the end of dosing interval. A high interindividual variability was shown. We enrolled 237 children, 83 receiving intravenous and 154 oral voriconazole. A positive correlation between drug dose and drug plasma exposure was observed. Considering intravenous route, patients with higher serum creatinine had higher voriconazole concentrations; a positive correlation was found among drug exposure and age. Sex significantly influenced drug levels: males had higher median drug concentrations than females (P < 0.001). Close voriconazole pharmacokinetics monitoring should help individualize antifungal therapy for children.

Pharmacokinetic evaluation of oral itraconazole for antifungal prophylaxis in children

Itraconazole is a first-generation triazole agent with an extended spectrum of activity; it is licensed in adults for superficial and systemic fungal infections; no recommendation has been yet established for use in children patients. Its variable and unpredictable oral bioavailability make it difficult to determine the optimal dosing regimen. Hence, therapeutic drug monitoring, highly available in clinical practice, may improve itraconazole treatment success and safety. The aim of the study was to describe in paediatrics the oral itraconazole pharmacokinetics, used for prophylaxis. Moreover, we evaluated the utility of its therapeutic drug monitoring in this cohort. A fully validated chromatographic method was used to quantify itraconazole concentration in plasma collected from paediatric patients, at the end of dosing interval. Associations between variables were tested using the Pearson test. Mann-Whitney U test has been used to probe the influence of categorical variables on continuous ones. Any predictive power of the considered variables was finally evaluated through univariate and multivariate linear and logistic regression analyses. A high inter-individual variability was shown; ethnicity (beta coefficient, β -0.161 and interval of confidence at 95%, IC -395.035; -62.383) and gender (β 0.123 and IC 9.590; 349.395) remained in the final linear regression model with P value of .007 and .038, respectively. This study highlights that therapeutic drug monitoring is required to achieve an adequate target itraconazole serum exposure.

Treatment with PEG-IFN and ribavirin in patients with chronic hepatitis C, low grade of hepatic fibrosis, genotype 1 and 4 and favorable IFNL3 genotype: A pharmacogenetic prospective study

The new direct-acting antivirals agents (DAAs) rapidly changed the treatment approach in chronic hepatitis C (CHC); however, the interferon (IFN)-free therapies availability is currently different in some countries, due to higher costs of these drugs. Naïve treated patients, who are not eligible for IFN-free therapies, could be selected for standard dual treatment with pegylated (PEG)-IFN and ribavirin (RBV), through IFN lambda 3 gene polymorphisms and fibrosis stage evaluation. Inclusion criteria were: naïve treated CHC patients with GT1 or GT4, without major contraindication to PEG-IFN or RBV, with fibrosis stage F0-F2 and IFNL3 rs8099917/rs12979860 TT/CC genotypes. 65 patients were included in the study. Overall SVR was observed in 50 patients (76.9%); SVR rates among different genotypes were as follows: 15 with GT1a (71.4%), 27 with GT1b (79.4%) and 8 for GT4 (80%). The RBV cutoff at 2weeks of 1800ng/mL, predictor of RVR, was determined (p=0.003; sensibility=60.4%, specificity=88.2%, positive predictive value=88.9%, negative predictive value=100%). In multivariate analysis, factors significantly associated with treatment failure were living alone condition (OR=4.302; 95%IC=1.254-16.257; p=0.034) and RBV plasma level <1800ng/mL at 2weeks (OR=4.970; 95%IC=1.405-17.565; p=0.009). Considering a pharmacogenetic-guided approach, dual therapy with PEG-IFN and RBV can be considered a reliable option for patients ineligible for IFN-free treatments, who are motivated and well informed about all the aspects related to PEG-IFN administration.

Role of simeprevir plasma concentrations in HCV treated patients with dermatological manifestations

BACKGROUND AND AIMS

Up till now the role of simeprevir plasma concentrations has not been described in treated patients affected by chronic hepatitis C and with dermatological side-effects. In this study, we have evaluated a possible relationship between plasma levels and the onset of skin complaints for the first time.

METHODS

We report a clinical and pharmacokinetic analysis of 56 patients treated with simeprevir-based therapies.

RESULTS

Simeprevir plasma concentrations were significantly related to dermatological side-effects at early time-points (P<0.001). In logistic regression, simeprevir concentrations at 1 week was the best predictive factor forskin symptoms (OR=1.901, 95%IC: 1.001-2.304; P=0.007).

CONCLUSION

Simeprevir plasma measurements could be a useful tool in a real-life clinical setting for prevention of dermatological symptoms.

Pharmacogenetic analysis of hepatitis C virus related mixed cryoglobulinemia

AIM

Mixed cryoglobulinemia (MC) is an extra hepatic hepatitis C virus related problem and different studies suggested genetics' role in predicting this complication. We evaluated the influence of SNPs in IL-28B, SLC29A1, SLC28A2, NT5C2, HNF4 and ABCB1 genes in MC prediction.

PATIENTS & METHODS

SNPs were evaluated through real-time PCR.

RESULTS

 ABCB1 (gene encoding P-glycoprotein) 3435C>T SNP was associated with MC presence (p = 0.034): related to T allele carriers (CC vs CT/TT), we reached a p-value of 0.013. In the logistic regression analysis baseline viral load >600.000 IU/ml (p < 001), IL28B rs8099917/rs12979860 TT/CC (p < 0.001), NT5 (gene encoding for 5' nucleotidase) 153 TC (p = 0.012) and ABCB1 3435 CT/TT (p = 0.034) genotypes predicted MC presence.

CONCLUSION

These data could help clinicians to identify patients with higher probability to show MC extra hepatic complication.