Paxlovid (nirmatrelvir plus ritonavir) is a new oral antiviral therapeutic for the treatment of COVID-19. Nirmatrelvir is an inhibitor of SARS-CoV-2 main protease, while ritonavir is used as a CYP3A inhibitor in low doses to slow the metabolism of nirmatrelvir, thus enhancing their therapeutic effect. The isoenzyme CYP3A4 is responsible for at least part of the oxidative metabolism of approximately 60% of available medications and ritonavir is therefore a significant source of drug interactions. We describe here the drugs that are contraindicated or should be used with or without precautions when Paxlovid (nirmaltrevir plus ritonavir) should be administered according to each fact sheet in force at the Spanish Agency for Medicines and Health Products.

Cefiderocol is a new cephalosporin with a catechol in its chemical structure faciliting its access to the interior of bacteria through iron channels. In addition, it is broadly stable to beta-lactamases. The pharmacokinetic profile is a beta-lactam one: no oral absorption, and with a wide distribution within the vascular space and the interstitial fluid of well vascularized tissues, reaching therapeutic concentrations in the alveolar lavage fluid and within the macrophage. The binding of cefiderocol to human plasma proteins, primarily albumin, is moderate (range 40-60%). The terminal elimination half-life in healthy adult subjects was 2 to 3 hours. Cefiderocol is mainly renally eliminated, so dose adjustments are recommended in subjects with moderate / severe renal impairment, in case of dialysis, and probably in patients with external clearance. Like other beta-lactams, the PK / PD parameter that has been shown to best correlate with efficacy is the efficacy time of unbound plasma concentrations (%fT>MIC), which must be close to 100% to achieve a bactericidal effect. This is possible with 2 g in a 3-hour infusion every 8 hours. In controlled trials appears to be well tolerated, similar to comparators: meropenem or imipenem-cilastatin. Cefiderocol has no apparent clinically significant effect on ECG parameters nor on plasma iron values.

Liposomal amphotericin B is a lipid formulation of the antifungal drug amphotericin B with some distinguishing characteristics in its pharmacological behavior that entail some clinical differences of great interest. The significant improvement in the systemic and renal tolerability is one of them. This fact is related to the great stability of the liposome, promoted by its negative charge, the presence of cholesterol and the remarkable thermo-stability of the remaining lipids that compose it. In this situation, amphotericin B seems to be released from the liposome not spontaneously but when the liposome binds to the ergosterol in the fungal cell membrane. For this reason, there is almost no free amphotericin B in plasma or tissues, although it seems that its availability is greater when there is fungal infection. As a consequence, when the pharmacokinetic behavior is studied, the concentration and availability of liposomal amphotericin B are very high, and its volume of distribution is reduced in comparison with the other formulations. (C) 2021 Asociacion Espafiola de Micologla. Published by Elsevier Espafia, S.L.U. All rights reserved.

Severe infection and its evolution to sepsis are becoming more prevalent every day and are among the leading causes of critical illness and mortality. Proper management is crucial to improve prognosis. This document addresses three essential points that have a significant impact on this objective: a) early recognition of patients with sepsis criteria, b) identification of those patients who suffer from an infection and have a high risk of progressing to sepsis, and c) adequate selection and optimization of the initial antimicrobial treatment.

Background Invasive mould diseases are associated with high morbidity, mortality and economic impact. Its treatment is often started prior to differential pathogen diagnosis. Isavuconazole is approved for treatment of invasive aspergillosis (IA) and invasive mucormycosis (IM) when amphotericin-B is not indicated. Objectives To estimate the cost-effectiveness of isavuconazole vs voriconazole for the treatment of adult patients with possible IA prior to differential pathogen diagnosis, in Spain. Methods A decision tree analysis was performed using the Spanish Healthcare System perspective. Among all patients with possible IA, it was considered that 7.81% actually had IM. Costs for laboratory analysis, management of adverse events, hospitalisation and drugs per patient, deaths and long-term effects in life years (LYs) and quality-adjusted LYs (QALYs) were considered. Efficacy data were obtained from clinical trials and utilities from the literature. Deterministic and probabilistic sensitivity analyses (PSA) were conducted. Results In patients with possible IA and when compared to voricanozole, isavuconazole showed an incremental cost of 4758.53euro, besides an incremental effectiveness of +0.49 LYs and +0.41 QALYs per patient. The Incremental Cost Effectiveness Ratio was 9622.52euro per LY gained and 11,734.79euro per QALY gained. The higher cost of isavuconazole was due to drug acquisition. Main parameters influencing results were mortality, treatment duration and hospitalisation days. The PSA results showed that isavuconazole has a probability of being cost-effective of 67.34%, being dominant in 24.00% of cases. Conclusions Isavuconazole is a cost-effective treatment compared to voriconazole for patients with possible IA for a willingness to pay threshold of 25,000euro per additional QALY.

Background and Objective Bilastine is a non-sedating H1 antihistamine indicated for the treatment of allergic rhinoconjunctivitis and urticaria. The aim of this trial was to assess the bioequivalence of three novel pediatric oral formulations of bilastine. Methods An open label, randomized, four-treatment-period, four-sequence, crossover, single-center study was conducted in 23 healthy volunteers. Each subject received four single doses of bilastine under fasting conditions: a 10-mg orodispersible tablet (DT1), a 10-mg oral solution (SOL), a 10-mg orodispersible tablet without water (DT2dry), and a 10-mg orodispersible tablet with water (DT2water, reference formulation). Blood samples were collected during 72 h with a washout period of at least 7 days. Bilastine maximum plasma concentration (C-max) and area under the plasma concentration-time curve between 0 to t time (AUC(0-t)) were calculated to assess bioequivalence. Tolerability was evaluated throughout the study. Results The three oral pediatric formulations tested were bioequivalent to the reference formulation as determined by the ratio test/reference of the geometric mean and their 90% confidence intervals (between 0.80 and 1.25) for the C-max, AUC(0-t) and AUC(0-infinity.) Bilastine was well tolerated when administered indistinctly as an orodispersible tablet or as an oral solution. Conclusion The three oral pediatric formulations tested were found to be bioequivalent to the reference formulation. All formulations were well tolerated.

Objectives: The primary objective is to determine the efficacy of a single dose of ivermectin, administered to low risk, non-severe COVID-19 patients in the first 48 hours after symptom onset to reduce the proportion of patients with detectable SARS-CoV-2 RNA by Polymerase Chain Reaction (PCR) test from nasopharyngeal swab at day 7 post-treatment. The secondary objectives are: 1.To assess the efficacy of ivermectin to reduce the SARS-CoV-2 viral load in the nasopharyngeal swab at day 7 post treatment.2.To assess the efficacy of ivermectin to improve symptom progression in treated patients.3.To assess the proportion of seroconversions in treated patients at day 21.4.To assess the safety of ivermectin at the proposed dose.5.To determine the magnitude of immune response against SARS-CoV-2.6.To assess the early kinetics of immunity against SARS-CoV-2. Trial design: SAINT is a single centre, double-blind, randomized, placebo-controlled, superiority trial with two parallel arms. Participants will be randomized to receive a single dose of 400 ¿g/kg ivermectin or placebo, and the number of patients in the treatment and placebo groups will be the same (1:1 ratio). Participants: The population for the study will be patients with a positive nasopharyngeal swab PCR test for SARS-CoV-2, with non-severe COVID-19 disease, and no risk factors for progression to severity. Vulnerable populations such as pregnant women, minors (i.e.; under 18 years old), and seniors (i.e.; over 60 years old) will be excluded. Inclusion criteria 1. Patients diagnosed with COVID-19 in the emergency room of the Clínica Universidad de Navarra (CUN) with a positive SARS-CoV-2 PCR. 2. Residents of the Pamplona basin ("Cuenca de Pamplona"). 3. The patient must be between the ages of 18 and 60 years of age. 4. Negative pregnancy test for women of child bearing age*. 5. The patient or his/her representative, has given informed consent to participate in the study. 6. The patient should, in the PI's opinion, be able to comply with all the requirements of the clinical trial (including home follow up during isolation). Exclusion criteria 1. Known history of ivermectin allergy. 2. Hypersensitivity to any component of ivermectin. 3. COVID-19 pneumonia. Diagnosed by the attending physician.Identified in a chest X-ray. 4. Fever or cough present for more than 48 hours. 5. Positive IgG against SARS-CoV-2 by rapid diagnostic test. 6. Age under 18 or over 60 years. 7. The following co-morbidities (or any other disease that might interfere with the study in the eyes of the PI): Immunosuppression.Chronic Obstructive Pulmonary Disease.Diabetes.Hypertension.Obesity.Acute or chronic renal failure.History of coronary disease.History of cerebrovascular disease.Current neoplasm. 8. Recent travel history to countries that are endemic for Loa loa (Angola, Cameroon, Central African Republic, Chad, Democratic Republic of Congo, Ethiopia, Equatorial, Guinea, Gabon, Republic of Congo, Nigeria and Sudan). 9. Current use of CYP 3A4 or P-gp inhibitor drugs such as quinidine, amiodarone, diltiazem, spironolactone, verapamil, clarithromycin, erythromycin, itraconazole, ketoconazole, cyclosporine, tacrolimus, indinavir, ritonavir or cobicistat. Use of critical CYP3A4 substrate drugs such as warfarin. *Women of child bearing age may participate if they use a safe contraceptive method for the entire period of the study and at least one month afterwards. A woman is considered to not have childbearing capacity if she is post-menopausal (minimum of 2 years without menstruation) or has undergone surgical sterilization (at least one month before the study). The trial is currently planned at a single center, Clínica Universidad de Navarra, in Navarra (Spain), and the immunology samples will be analyzed at the Barcelona Institute for Global Health (ISGlobal), in Barcelona (Spain). Participants will be recruited by the investigators at the emergency room and/or COVID-19 area of the CUN. They will remain in the trial for a period of 28 days at their homes since they will be patients with mild disease. In the interest of public health and to contain transmission of infection, follow-up visits will be conducted in the participant's home by a clinical trial team comprising nursing and medical members. Home visits will assess clinical and laboratory parameters of the patients. Intervention and comparator: Ivermectin will be administered to the treatment group at a 400¿g/Kg dose (included in the EU approved label of Stromectol and Scabioral). The control group will receive placebo. There is no current data on the efficacy of ivermectin against the virus in vivo, therefore the use of placebo in the control group is ethically justified. Main outcomes: Primary Proportion of patients with a positive SARS-CoV-2 PCR from a nasopharyngeal swab at day 7 post-treatment. Secondary 1.Mean viral load as determined by PCR cycle threshold (Ct) at baseline and on days 4, 7, 14, and 21.2.Proportion of patients with fever and cough at days 4, 7, 14, and 21 as well as proportion of patients progressing to severe disease or death during the trial.3.Proportion of patients with seroconversion at day 21.4.Proportion of drug-related adverse events during the trial.5.Median levels of IgG, IgM, IgA measured by Luminex, frequencies of innate and SARS-CoV-2-specific T cells assessed by flow cytometry, median levels of inflammatory and activation markers measured by Luminex and transcriptomics.6.Median kinetics of IgG, IgM, IgA levels during the trial, until day 28. Randomisation: Eligible patients will be allocated in a 1:1 ratio using a randomization list generated by the trial statistician using blocks of four to ensure balance between the groups. A study identification code with the format "SAINT-##" (##: from 01 to 24) will be generated using a sequence of random numbers so that the randomization number does not match the subject identifier. The sequence and code used will be kept in an encrypted file accessible only to the trial statistician. A physical copy will be kept in a locked cabinet at the CUN, accessible only to the person administering the drug who will not enrol or attend to patient care. A separate set of 24 envelopes for emergency unblinding will be kept in the study file. Blinding (masking): The clinical trial team and the patients will be blinded. The placebo will not be visibly identical, but it will be administered by staff not involved in the clinical care or participant follow up. Numbers to be randomised (sample size): The sample size is 24 patients: 12 participants will be randomised to the treatment group and 12 participants to the control group. Trial status: Current protocol version: 1.0 dated 16 of April 2020. Recruitment is envisioned to begin by May 14th and end by June 14th. Trial registration: EudraCT number: 2020-001474-29, registered April 1st. Clinicaltrials.gov: submitted, pending number FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

Ceftobiprole shows many similar pharmacokinetic properties to other cephalosporins, except for not being orally bioactive, and that it is administered by IV infusion as the prodrug ceftobiprole medocaril, which is subsequently hydrolyzed in the blood into the active molecule. Distribution focus in extracellular fluid and active antibiotic concentration has been proven in different corporal tissues using dosing regimen of 500 mg intravenous infusion over 2 h every 8 h. Ceftobiprole is eliminated exclusively into the urine, thus the reason why dose adjustment is required for patients with moderate or severe renal impairment, or increased creatinine clearance. However, there is no need for dose adjustments related with other comorbidities and patients' conditions such as age, body weight. Although considering distribution features, molecular weight and dose fraction, increase dosing regimen might be necessary in patients using renal replacement therapy. The half-life of ceftobiprole is more than 3 h, allowing to easily reach optimal PK/PD parameters with the infusion time of 2 h, using the usual dosing regimen.

OBJECTIVE: To describe the pharmacokinetic (PK) profile of anidulafungin and to evaluate its concentration in the peritoneal fluid (PF) of patients suspected of suffering from peritoneal infection undergoing abdominal surgery, in order to ensure that therapeutic levels are achieved within the peritoneal cavity. METHODS: A descriptive, open, prospective, observational, multicentre and non-interventional study was performed. Anidulafungin was used at conventional doses. Blood and PF samples were obtained on day 2 of treatment or on any of the following days. RESULTS: A total of 31 patients in a serious clinical condition, as demonstrated by high mean clinical severity scale scores (APACHE II and SOFA scores), were included in the study. The mean area under the curve (AUC) in PF was 30% (31±19%) of that determined in the plasma and the maximum concentration (Cmax) reached in PF (mg/l) was close to 1 (0.9±0.5). No adverse effects were observed in any of the 31 patients. CONCLUSIONS: Anidulafungin at conventional doses reaches PF concentrations that exceed the minimum inhibitory concentration of the usual Candida spp, which explains the proven efficacy of this echinocandin in the treatment of Candida peritonitis in critically ill patients.