Role of airway epithelium in viral respiratory infections: Can carbocysteine prevent or mitigate them?

Alterations in airway epithelial homeostasis increase viral respiratory infections risk. Viral infections frequently are associated with chronic obstructive pulmonary disease (COPD) exacerbations, events that dramatically promote disease progression. Mechanism promoting the main respiratory viruses entry and virus-evocated innate and adaptive immune responses have now been elucidated, and an oxidative stress central role in these pathogenic processes has been recognized. Presence of reactive oxygen species in macrophages and other cells allows them to eliminate virus, but its excess alters the balance between innate and adaptive immune responses and proteases/anti-proteases and leads to uncontrolled inflammation, tissue damage, and hypercoagulability. Different upper and lower airway cell types also play a role in viral entry and infection. Carbocysteine is a muco-active drug with anti-oxidant and anti-inflammatory properties used for the management of several chronic respiratory diseases. Although the use of anti-oxidants has been proposed as an effective strategy in COPD exacerbations management, the molecular mechanisms that explain carbocysteine efficacy have not yet been fully clarified. The present review describes the most relevant features of the common respiratory virus pathophysiology with a focus on epithelial cells and oxidative stress role and reports data supporting a putative role of carbocysteine in viral respiratory infections.

NSAIDs for early management of acute respiratory infections.

PURPOSE OF REVIEW: To review the rationale for and the potential clinical benefits of an early approach to viral acute respiratory infections with NSAIDs to switch off the inflammatory cascade before the inflammatory process becomes complicated. RECENT FINDINGS: It has been shown that in COVID-19 as in other viral respiratory infections proinflammatory cytokines are produced, which are responsible of respiratory and systemic symptoms. There have been concerns that NSAIDs could increase susceptibility to SARS-CoV-2 infection or aggravate COVID-19. However, recent articles reviewing experimental research, observational clinical studies, randomized clinical trials, and meta-analyses conclude that there is no basis to limit the use of NSAIDs, which may instead represent effective self-care measures to control symptoms. SUMMARY: The inflammatory response plays a pivotal role in the early phase of acute respiratory tract infections (ARTIs); a correct diagnosis of the cause and a prompt therapeutic approach with NSAIDs may have the potential to control the pathophysiological mechanisms that can complicate the condition, while reducing symptoms to the benefit of the patient. A timely treatment with NSAIDs may limit the inappropriate use of other categories of drugs, such as antibiotics, which are useless when viral cause is confirmed and whose inappropriate use is responsible for the development of resistance.

Effect of digoxin on all-cause and cardiovascular mortality in patients with atrial fibrillation with and without heart failure: an umbrella review of systematic reviews and 12 meta-analyses.

PURPOSE: To perform a systematic umbrella review with meta-analysis to evaluate the certainty of evidence on mortality risk associated with digoxin use in patients with atrial fibrillation (AF) with or without heart failure (HF). METHODS: We systematically searched MEDLINE, Embase, and Web of Science databases from inception to 19 October 2021. We included systematic reviews and meta-analyses of observational studies investigating digoxin effects on mortality of adult patients with AF and/or HF. The primary outcome was all-cause mortality; secondary outcome was cardiovascular mortality. Certainty of evidence was evaluated by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool and the quality of systematic reviews/meta-analyses by the A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR2) tool. RESULTS: Eleven studies accounting for 12 meta-analyses were included with a total of 4,586,515 patients. AMSTAR2 analysis showed a high quality in 1, moderate in 5, low in 2, and critically low in 3 studies. Digoxin was associated with an increased all-cause mortality (hazard ratio [HR] 1.19, 95% confidence interval [95%CI] 1.14-1.25) with moderate certainty of evidence and with an increased cardiovascular mortality (HR 1.19, 95%CI 1.06-1.33) with moderate certainty of evidence. Subgroup analysis showed that digoxin was associated with all-cause mortality both in patients with AF alone (HR 1.23, 95%CI 1.19-1.28) and in those with AF and HF (HR 1.14, 95%CI 1.12-1.16). CONCLUSION: Data from this umbrella review suggests that digoxin use is associated with a moderate increased risk of all-cause and cardiovascular mortality in AF patients regardless of the presence of HF. TRIAL REGISTRATION: This review was registered in PROSPERO (CRD42022325321).

High prevalence of anal papillomavirus infection in men who have sex with men PrEP users.

OBJECTIVES: Human papillomavirus (HPV) is the most common STI and is associated with a wide range of diseases from anogenital warts to malignancies. Anal HPV infection is considerably more common in men who have sex with men (MSM) living with HIV. Aims of the present study are to (i) describe the prevalence of anal HPV infection in MSM who started pre-exposure prophylaxis (PrEP) and (ii) analyse factors associated with anal infection from genotypes that would be covered by nonavalent vaccination. METHODS: This monocentric, cross-sectional study included all subjects who started PrEP from May 2018 to November 2021. PrEP candidates underwent full behavioural and clinical evaluation, including digital anal rectal examination and swabbing for HPV determination. Descriptive statistics, Mann-Whitney U test for continuous and χ2 tests for categorical variables were adopted. Unadjusted and adjusted regression analyses were performed to assess factors associated with positive anal swabs and to the presence of genotypes covered by the nonavalent vaccination. RESULTS: The analysis included 288 subjects: anal swabs tested positive in 87.2% of cases, 79.2% of the subjects had a high-risk genotype (mainly 16), whereas 67.4% had a genotype covered by nonavalent vaccine. Sexual role was the only factor associated with anal HPV infection. Use of recreational drugs and a diagnosis of ≥2 STIs correlated with the presence of genotypes that would have been covered by vaccine, while previous vaccination had a protective role. CONCLUSIONS: PrEP candidates showed a high prevalence of anal HPV infection, especially due to high-risk genotypes, comparable to what has been reported in MSM living with HIV.

Neurological manifestations in patients hospitalized with COVID-19: A retrospective analysis from a large cohort in Northern Italy.

SARS-CoV2 infection is a systemic disease that may involve multiple organs, including the central nervous system (CNS). Aims of our study are to describe prevalence and clinical features of neurological manifestations, mortality and hospital discharge in subjects hospitalized with COVID-19. All individuals admitted for to our hospital COVID-19 were retrospectively included. Patients were classified according to the symptoms at hospital entry in (1) isolated respiratory, (2) combined respiratory and neurologic, (3) isolated neurologic and (4) stroke manifestations. Descriptive statistics and nonparametric tests to compare the groups were calculated. Kaplan Meier probability curves and multivariable Cox regression models for survival and hospital discharge were applied. The analysis included 901 patients: 42.6% showed a severe or critical disease with an overall mortality of 21.2%. At least one neurological symptom or disease was observed in 30.2% of subjects ranging from dysgeusia/anosmia (9.1%) to postinfective diseases (0.8%). Patients with respiratory symptoms experienced a more severe disease and a higher in-hospital mortality compared to those who showed only neurologic symptoms. Kaplan Meier estimates displayed a statistically significant different survival among groups (p = 0.003): subjects with stroke had the worst. After adjusting for risk factors such as age, sex and comorbidity, individuals with isolated neurologic manifestations exhibited a better survival (aHR 0.398, 95% CI [0.206, 0.769], p = 0.006). Neurologic manifestations in COVID-19 are common but heterogeneous and mortality in subjects with isolated neurologic manifestations seems lower than in those with respiratory symptoms.

Types of erythropoiesis-stimulating agents and risk of end-stage kidney disease and death in patients with non-dialysis chronic kidney disease.

BACKGROUND: Despite the widespread use of erythropoiesis-stimulating agents (ESAs) to treat anaemia, the risk of adverse outcomes associated with the use of different types of ESAs in non-dialysis chronic kidney disease (CKD) is poorly investigated. METHODS: From a pooled cohort of four observational studies, we selected CKD patients receiving short-acting (epoetin α/ß; n = 299) or long-acting ESAs (darbepoetin and methoxy polyethylene glycol-epoetin ß; n = 403). The primary composite endpoint was end-stage kidney disease (ESKD; dialysis or transplantation) or all-cause death. Multivariable Cox models were used to estimate the relative risk of the primary endpoint between short- and long-acting ESA users. RESULTS: During follow-up [median 3.6 years (interquartile range 2.1-6.3)], the primary endpoint was registered in 401 patients [166 (72%) in the short-acting ESA group and 235 (58%) in the long-acting ESA group]. In the highest tertile of short-acting ESA dose, the adjusted risk of primary endpoint was 2-fold higher {hazard ratio [HR] 2.07 [95% confidence interval (CI) 1.37-3.12]} than in the lowest tertile, whereas it did not change across tertiles of dose for long-acting ESA patients. Furthermore, the comparison of ESA type in each tertile of ESA dose disclosed a significant difference only in the highest tertile, where the risk of the primary endpoint was significantly higher in patients receiving short-acting ESAs [HR 1.56 (95% CI 1.09-2.24); P = 0.016]. Results were confirmed when ESA dose was analysed as continuous variable with a significant difference in the primary endpoint between short- and long-acting ESAs for doses >105 IU/kg/week. CONCLUSIONS: Among non-dialysis CKD patients, the use of a short-acting ESA may be associated with an increased risk of ESKD or death versus long-acting ESAs when higher ESA doses are prescribed.

Sex differences in electrolyte imbalances caused by SARS-CoV-2: A cross-sectional study.

BACKGROUND: Since SARS-CoV-2 spread, evidence regarding sex differences in progression and prognosis of COVID-19 have emerged. Besides this, studies on patients' clinical characteristics have described electrolyte imbalances as one of the recurrent features of COVID-19. METHODS: We performed a cross-sectional study on all patients admitted to the emergency department (ED) from 1 March to 31 May 2020 who had undergone a blood gas analysis and a nasopharyngeal swab test for SARS-CoV-2 by rtPCR. We defined positive patients as cases (n = 710) and negatives as controls (n = 619), for a total number of patients of 1.329. The study was approved by the local ethics committee Area 3 Milan. Data were automatically extracted from the hospital laboratory SQL-based repository in anonymised form. We considered as outcomes potassium (K+ ), sodium (Na+ ), chlorine (Cl- ) and calcium (Ca++ ) as continuous and as categorical variables, in their relation with age, sex and SARS-CoV-2 infection status. RESULTS: We observed a higher prevalence of hypokalaemia among patients positive for SARS-CoV-2 (13.7% vs 6% of negative subjects). Positive patients had a higher probability to be admitted to the ED with hypokalaemia (OR 2.75, 95% CI 1.8-4.1, P < .0001) and women were twice as likely to be affected than men (OR 2.43, 95% CI 1.67-3.54, P < .001). Odds ratios for positive patients to manifest with an alteration in serum Na+ was (OR 1.6, 95% CI 1.17-2.35, P < .001) and serum chlorine (OR 1.6, 95% CI 1.03-2.69, P < .001). Notably, OR for positive patients to be hypocalcaemic was 7.2 (95% CI 4.8-10.6, P < .0001) with a low probability for women to be hypocalcaemic (OR 0.63, 95% CI 0.4-0.8, P = .005). CONCLUSIONS: SARS-CoV-2 infection is associated with a higher prevalence of hypokalaemia, hypocalcaemia, hypochloraemia and sodium alterations. Hypokalaemia is more frequent among women and hypocalcaemia among men.

Differences in PARP Inhibitors for the Treatment of Ovarian Cancer: Mechanisms of Action, Pharmacology, Safety, and Efficacy.

Poly(ADP-ribose) polymerases (PARP) are proteins responsible for DNA damage detection and signal transduction. PARP inhibitors (PARPi) are able to interact with the binding site for PARP cofactor (NAD+) and trapping PARP on the DNA. In this way, they inhibit single-strand DNA damage repair. These drugs have been approved in recent years for the treatment of ovarian cancer. Although they share some similarities, from the point of view of the chemical structure and pharmacodynamic, pharmacokinetic properties, these drugs also have some substantial differences. These differences may underlie the different safety profiles and activity of PARPi.

The Contribution of Clinical Pharmacologists in Precision Medicine: An Opportunity for Health Care Improvement.

BACKGROUND: Clinical pharmacologists play an important role and have professional value in the field, especially regarding their role within precision medicine (PM) and personalized therapies. OBJECTIVE: In this work, we sought to stimulate debate on the role of clinical pharmacologists. METHODS: A literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, through electronic consultation of 2 databases, PubMed/Medline and Embase, and Google Scholar with manual research taking into account the peer-reviewed literature such as observational studies, reviews, original research articles, comments, mini-reviews, and opinion papers published in English between 2010 and February 2020. Titles and abstracts were screened by 1 author, and studies identified for full-text analysis and selected according to inclusion criteria were agreed on by 2 reviewers. RESULTS: We identified a total of 535 peer-reviewed articles and the number of full texts eligible for the project was 43. Several publications highlight the clinical value of pharmacologists in highly complex hospitals, where the strategies of PM are implemented. Although there are still no studies measuring the clinical efficiency and the efficacy of clinical pharmacology services, and the applicability of PM protocols, this review shows the considerable debate around the future mission of clinical pharmacology services as a bridging discipline capable of combining the complex knowledge and different professional skills needed to fully implement PM. CONCLUSIONS: Various strategies have been conceived and planned to facilitate the transition from mainstream medicine to PM, which will enable patients to be treated more accurately, with significant advantages in terms of safety and effectiveness of treatments. Therefore, in the future, to ensure that the evolutionary process of medicine can involve as many patients and caregivers as possible, infrastructures capable of bringing together different multidisciplinary skills among health professionals will have to be implemented. Clinical pharmacologists could be the main drivers of this strategy because they already, with their multidisciplinary training, operate in a series of services in high-level hospitals, facilitating the clinical governance of the most challenging patients. The implementation of these strategies will lastly allow national health organizations to adequately address the management and therapeutic challenges related to the advent of new drugs and cell and gene therapies by facilitating the removal of economic and organizational barriers to ensure equitable access to PM. (Curr Ther Res Clin Exp. 2021; 82:XXX-XXX).

NSAIDs in patients with viral infections, including Covid-19: Victims or perpetrators?

Taking anti-inflammatory drugs, including non-steroidal (NSAIDs), during Covid-19 infection, how much is risky? The French Minister of Health, who has raised an alarm on a possible risk deriving from the use of ibuprofen for the control of fever and other symptoms during the disease, opened the debate a few days ago. In this paper we examine available evidence from preclinical and clinical studies that had analysed the role of COX in the inflammatory process and the effects of NSAIDs in patients with infections. Most of the published studies that suggested not protective effects of NSAIDs were mainly performed in vitro or on animals. Therefore, their meaning in humans is to be considered with great caution. Based also on data suggesting protective effects of NSAIDs, we concluded that currently there is no evidence suggesting a correlation between NSAIDs and a worsening of infections. Further studies will be certainly needed to better define the role of NSAIDs and particularly COX2 inhibitors in patients with infections. In the meantime, we must wait for results of the revision started by the PRAC on May 2019 on the association ibuprofen/ketoprofen​​​​​​ and worsening of infections. Since nowadays no scientific evidence establishes a correlation between NSAIDS and worsening of COVID-19, patients should be advice against any NSAIDs self-medication when COVID-19 like symptoms are present.

CDK4/6 Inhibitors in Breast Cancer Treatment: Potential Interactions with Drug, Gene, and Pathophysiological Conditions.

Palbociclib, ribociclib, and abemaciclib belong to the third generation of cyclin-dependent kinases inhibitors (CDKis), an established therapeutic class for advanced and metastatic breast cancer. Interindividual variability in the therapeutic response of CDKis has been reported and some individuals may experience increased and unexpected toxicity. This narrative review aims at identifying the factors potentially concurring at this variability for driving the most appropriate and tailored use of CDKis in the clinic. Specifically, concomitant medications, pharmacogenetic profile, and pathophysiological conditions could influence absorption, distribution, metabolism, and elimination pharmacokinetics. A personalized therapeutic approach taking into consideration all factors potentially contributing to an altered pharmacokinetic/pharmacodynamic profile could better drive safe and effective clinical use.

Chiral Recognition of Flexible Melatonin Receptor Ligands Induced by Conformational Equilibria.

N-anilinoethylamides are a class of melatoninergic agents with the aniline portion mimicking the indole ring of the natural ligand and the ethylamide chain reproducing that of melatonin. The simplest compound in this class, N-{2-[(3-methoxyphenyl)methylamino]ethyl}acetamide (UCM793), has nanomolar binding affinity for MT1 and MT2 membrane receptors. To explore the effect of chain conformation on receptor binding, a methyl group was inserted on the methylene alpha or beta to the amide nitrogen and conformational equilibria were investigated by NMR spectroscopy and molecular dynamics simulations. Receptor affinity was conserved only for the beta-methyl derivative, which also showed significant stereoselectivity, with the (S) enantiomer being the eutomer. Molecular dynamics simulations, validated by NMR spectroscopy, showed that the beta-methyl group affects the conformational preferences of the ethylamide chain. Docking into the receptor crystal structure provides a rationale for the observed chiral recognition, suggesting that the (S)-beta-methyl group favors the conformation that better fits the receptor binding site.

Calcium physiology, metabolism and supplementation: a glance at patients with ankylosing spondylitis.

The aim of this review is to describe the metabolism of calcium in ankylosing spondylitis compared to physiologic conditions, and to present the current evidence on the benefits and disadvantages of calcium supplementation in these patients. A narrative review of the literature was conducted using the PubMed database and a total of 65 articles were selected. Calcium is involved in many physiopathological processes, including inflammation, bone loss and bone formation, all of which occur in ankylosing spondylitis. Many ankylosing spondylitis patients suffer from concomitant osteopenia or osteoporosis, which represent indications for calcium supplementation. Conversely, there are still concerns about the use of calcium salts for the prevention of bone fragility in non-osteoporotic or non-osteopenic patients. In these cases, biologic agents may indirectly normalize calcium dysmetabolism by rebalancing the cytokine milieu, in turn associated with bone remodeling. Calcium supplements may be disadvantageous for entheseal calcifications, but so far there are no clear data confirming that such an association exists.

Intensive multidisciplinary management in critical care patients affected by severe necrotizing soft tissue infections: a cooperative method to improve the efficacy of treatment.

To illustrate the effectiveness of our intensive multidisciplinary management (IMM) in the treatment of severely ill patients with necrotizing soft tissue infections (NSTIs). A retrospective observational study was conducted in a general ICU. Thirty-two consecutive patients undergoing IMM were carefully compared with 30 consecutive patients receiving a standard management (SM). IMM combined intensive care management, early surgical debridement followed by daily inspection of surgical wounds, close microbiological surveillance, and targeted high-dose antibiotics. IMM was associated with the better decrease of daily SOFA score (p = 0.04). Also, IMM caused + 12% increase in the overall number of surgical procedures (p = 0.022) and a higher number of tissue biopsies/per day (median 0.63 versus 0.32; p = 0.025), leading to a more targeted antimicrobial changes (89.6% vs 51.6%; p < 0.00001). High-dose daptomycin (75% vs 36.7%; p = 0.002) and extended/continuous infusion of beta-lactams (75% vs 43.3%; p = 0.011) were more frequently utilized. A specific efficiency score correlated with the decrease of SOFA score (efficacy) in IMM patients only (p = 0.027). Finally, IMM was associated with a significant lower ICU mortality rate (15.6% vs 40%; p = 0.032). IMM was more effective than SM as it allowed the earlier control of infection and the faster reduction of multiple organ-dysfunction.

Comparative Emergence of Resistance to Clofoctol, Erythromycin, and Amoxicillin against Community-Acquired Bacterial Respiratory Tract Pathogens in Italy.

Due to increasing bacterial resistance and poor availability of new antibiotics, physicians need to use old, still active antibiotics more frequently. In this study, we focused on clo-foctol and aimed to verify the emergence of clofoctol resistance over time. Additionally, the ability of clofoctol to induce resistance under static and dynamic conditions was evaluated. The minimum inhibitory concentration (MIC) values measured in pathogens isolated from 1990 to 1995 were compared to those isolated from 2017 to 2018. The behaviour of clofoctol is similar to that of amoxicillin, while erythromycin shows a different behaviour with an increase in MIC. A rapid decline in CFUs with complete eradication at 96 and 120 h in the case of clofoctol and amoxicillin, respectively, was observed in a dynamic in vitro model of a pharmacokinetic simulation. Erythromycin provides a reduction in CFUs of approximately one order of magnitude for up to 72 h, and then re-growth is observed. The MIC trend was observed during 5 days of kinetic simulation. The clofoctol MICs remain almost stable up to 96 h, after which the colonies are no longer detectable. The MICs of amoxicillin show a 2-fold increase starting from 36 h; however, at 120 h the colonies are no longer detectable. The MICs of erythromycin show a progressive increase starting from 72 h and reaching 32-fold. Clofoctol maintains its activity towards the common pathogens of respiratory tract infections and, similarly to amoxicillin, does not induce resistance in a strain of Streptococcus pneumoniae, resulting in complete eradication, while erythromycin was able to select resistant mutants.

Melatonin Analogue Antiproliferative and Cytotoxic Effects on Human Prostate Cancer Cells.

Melatonin has been indicated as a possible oncostatic agent in different types of cancer, its antiproliferative role being demonstrated in several in vitro and in vivo experimental models of tumors. Specifically, melatonin was proven to inhibit cell growth of both androgen-dependent and independent prostate cancer cells, through various mechanisms. A number of melatonin derivatives have been developed and tested for their role in the prevention and treatment of neoplastic diseases. We recently proved the in vitro and in vivo anticancer activity of UCM 1037, a newly-synthetized melatonin analogue, on melanoma and breast cancer cells. In this study we evaluated UCM 1037 effects on cell proliferation, cell cycle distribution, and cytotoxicity in LNCaP, PC3, DU145, and 22Rv1 prostate cancer cells. We demonstrated significant dose- and time-dependent UCM 1037 antiproliferative effects in androgen-sensitive LNCaP and 22Rv1 cells. Data from flow cytometric studies suggest that UCM 1037 is highly cytotoxic in androgen-sensitive prostate cancer cells, although no substantial increase in the apoptotic cell fraction has been observed. UCM 1037 cytotoxic effects were much less evident in androgen-insensitive PC3 and DU145 cells. Experiments performed to gain insights into the possible mechanism of action of the melatonin derivative revealed that UCM 1037 down-regulates androgen receptor levels and Akt activation in LNCaP and 22Rv1 cells.

A pharmacokinetic study of GC-1 delivery using a nanochannel membrane device.

This study demonstrated a nanochannel membrane device (NMD) for controlled and sustained release of GC-1 in rats, in the context of the treatment of metabolic syndrome. Release profiles were established in vitro both with and without 5% labrasol for over 2 months. In vivo pharmacokinetic evaluation showed effective GC-1 plasma concentrations, which resulted in significant reductions in body weight after just one week of treatment when compared to the NMD releasing vehicle only (PBS). We also provided evidence that rats treated with NMD-GC-1 present sub-active thyroids and clear differences in the morphology of the epithelium and follicles as compared to the controls, while the heart showed changes in weight. Moreover, body temperatures remained stable throughout treatment, and glucose, pancreatic islet size, and liver histology appeared similar between the treated and control groups. Prolonged constant administration of GC-1 from the NMD proved to be a valid strategy to facilitate weight loss.

Thromboprophylaxis with low-molecular-weight heparins: an assessment of the methodological quality of studies.

Low-molecular-weight heparin (LMWH) represents the standard of care for prophylaxis of venous thromboembolism (VTE). We conducted a review of the evidence supporting the use of the different LMWHs employed in VTE prophylaxis, in different clinical settings, and analyzed its progression over time. To evaluate the standards of methodological quality of studies, we elaborated a quality assessment tool. By electronic databases, PubMed, MEDLINE, and Scopus databases, 249 articles deemed eligible for the analysis were selected. Several LMWHs did not have publications in all clinical settings. Extended duration of prophylaxis was documented only for a few LMWH. The quality score yielded statistically significant differences between the medians of the four settings (p = 0.0021) with a higher score in major orthopedic surgery (median, 16; 95% confidence interval [CI], 15-16) when compared with general surgery (median, 14; 95% CI, 13-14; p < 0.001). Median score for studies published after the year 1990 was higher than for those published earlier (p < 0.001). We conclude that the quality of the studies supporting LMWH for VTE prophylaxis in the different clinical settings is not homogeneous and inferior for studies performed before the year 1990. Clinical interchangeability of LMWHs in clinical practice remains a critical issue, and the selection of a product should be based on evidence available for each agent, and for each clinical indication derived from clinical trials.

Re-defining tigecycline therapy.

Tigecycline, the first member of the glycylcyclines, has been approved for complicated skin and soft tissue infections (cSSTIs) and complicated intra-abdominal infections (cIAIs). It has a wide range of activity against Gram-positive and Gram-negative bacteria, including anaerobes. Since its approval, the worldwide clinical use of tigecycline has been heterogeneous, either as a monotherapy or as a part of combination therapy, almost exclusively at the standard dosage, in patients with community-acquired (CA) infections as well as health-care associated (HCA) or nosocomial infections (HA), including infections caused by multidrug-resistant (MDR) bacteria. In recent years, issues and warnings of an increased mortality in these heterogeneous patients treated with tigecycline have been raised by meta-analyses and by regulatory agencies. Re-defining tigecycline therapy is a proposal, based on epidemiological, clinical, microbiological and pharmacological considerations, to distinguish patients who may be treated with monotherapy, according to the official indications and dosages, from those treated with combination treatment, mostly with high dosages in the setting of nosocomial IAIs, possibly caused by MDR bacteria or as a carbapenem-sparing strategy. Whilst available clinical data and guidelines suggest caution with monotherapy in severe infections, experience worldwide indicates that combination treatment with high-dosage tigecycline is increasingly used.

The impact of drug-drug interactions on pulmonary arterial hypertension therapy.

In clinical practice, pulmonary arterial hypertension (PAH) requires co-administration of multiple drugs to act on several pathogenic mechanisms; chronic pathologic conditions induce the onset of other concomitant diseases that need additional therapies. Combination treatment could exploit a synergism between administered drugs, increasing the effectiveness of the treatment and allowing dose reductions of the individual agents with a subsequent lower risk of toxicity. Conversely, concomitant administration of drugs may cause drug-drug interactions (DDIs), compromising treatment efficacy or increasing side effects, with a negative influence on disease progression. The choice of treatment is based on the fact that PAH is not caused by a single mechanism and that several syndromes, genetic abnormalities and environmental factors predispose to disease; therefore it is very likely that the use of treatments acting on a single pathway are not significantly effective. Moreover PAH is also frequently associated with other diseases that require concomitant clinical therapy. In this review we focused on the pharmacological treatment in PAH and related DDIs, evaluating alterations in drug transport, absorption, metabolism and excretion. This detailed analysis may be useful in clinical practice, as a better prediction of adverse events caused by DDIs in PAH improves the efficacy of combination therapy, resulting in reduced health care costs.