Pharmacovigilance and tuberculosis: applying the lessons of thioacetazone

Novel Thiourea Ligands-Synthesis, Characterization and Preliminary Study on Their Coordination Abilities

Two series of polydentate N,O,S-ligands containing thiourea fragments attached to a p-cresol scaffold, unsymmetrical mono-acylated bis-amines and symmetrical bis-thioureas, are obtained by common experiments. It is observed that the reaction output is strongly dependent on both bis-amine and thiocarbamic chloride substituents. The products are characterized by 1D and 2D NMR spectra in solution and by single crystal XRD. A preliminary study on the coordination abilities of selected products is performed by ITC at around neutral media.

The Struggle to End a Millennia-Long Pandemic: Novel Candidate and Repurposed Drugs for the Treatment of Tuberculosis

This article provides an encompassing review of the current pipeline of putative and developed treatments for tuberculosis, including multidrug-resistant strains. The review has organized each compound according to its site of activity. To provide context, mention of drugs within current recommended treatment regimens is made, thereafter followed by discussion on recently developed and upcoming molecules at established and novel targets. The review is designed to provide a clinically applicable understanding of the compounds that are deemed most currently relevant, including those already under clinical study and those that have shown promising pre-clinical results. An extensive review of the efficacy and safety data for key contemporary drugs already incorporated into treatment regimens, such as bedaquiline, pretomanid, and linezolid, is provided. The three levels of the bacterial cell wall (mycolic acid, arabinogalactan, and peptidoglycan layers) are highlighted and important compounds designed to target each layer are delineated. Amongst others, the highly optimistic and potent anti-mycobacterial activity of agents such as BTZ-043, PBTZ 169, and OPC-167832 are emphasized. The evolving spectrum of oxazolidinones, such as sutezolid, delpazolid, and TBI-223, all aiming to exceed the efficacy achieved with linezolid yet offer a safer alternative to the potential toxicity, are reviewed. New and exciting prospective agents with novel mechanisms of impact against TB, including 3-aminomethyl benzoxaboroles and telacebec, are underscored. We describe new diaryloquinolines in development, striving to build on the immense success of bedaquiline. Finally, we discuss some of these compounds that have shown encouraging additive or synergistic benefit when used in combination, providing some promise for the future in treating this ancient scourge.

Torsade de pointes associated with chloroquine, hydroxychloroquine, and azithromycin: a retrospective analysis of individual case safety reports from VigiBase

PURPOSE

To analyze the cases of torsade de pointes (TdP) and related symptoms reported in association with chloroquine (CQ), hydroxychloroquine (HCQ), and azithromycin (AZT) to the World Health Organization (WHO) global database of individual case safety reports (ICSRs) for drug monitoring (VigiBase) using qualitative and quantitative pharmacovigilance approaches.

METHODS

The main characteristics of the ICSRs reporting TdP with CQ, HCQ, and AZT have been summarized. Co-reported drugs with risk to cause QT prolongation have been described. Reporting odds ratios (RORs) as a measure of disproportionality for reported TdP and individual drugs have been calculated.

RESULTS

One hundred seventy ICSRs reporting TdP in association with the drugs of interest were identified (CQ: 11, HCQ: 31, CQ + HCQ: 1, HCQ + AZT: 27, AZT: 100). From these, 41 (24.3%) were received during the pandemic period (December 2019 to February 2021). The median age of the patients was 63, 53, and 63 years old for CQ, HCQ, and AZT, respectively. Reports included concomitant use of other QT-prolonging drugs (CQ 25.0%, HCQ 71.2%, AZT 64.6%). A proportion of the cases were fatal (CQ 25.0%, HCQ 8.6%, AZT 16.1%). Increased disproportionality has been found for the individual drugs and TdP: CQ (ROR: 7.41, 95% confidence interval (CI): 3.82, 12.96), HCQ (ROR: 8.49, 95% CI: 6.57, 10.98), azithromycin (ROR: 8.06, 95% CI: 6.76, 9.61). Disproportionality was also found for other related symptoms, Standardized MedDRA Query for torsade de pointes/QT prolongation (narrow): CQ (ROR: 11.95, 95% CI: 10.04-14.22); HCQ (ROR: 20.43, 95% CI: 19.13, 21.83), AZT (ROR: 7.78, 95% CI: 7.26, 8.34).

CONCLUSIONS

The prescription of CQ, HCQ, and AZT should be restricted to therapeutic indications with established positive benefit/risk profile. Doctors and patients should be aware of this potential adverse reaction especially when several risk factors are present.

Tuberculosis drug safety and pharmacovigilance in health system of Kosova: A cross-sectional analysis

BACKGROUND

Tuberculosis (TB) remains a significant worldwide social and life-threatening epidemiological problem. Because this disease requires multiple drug treatment and prolonged therapy for several months, followed by a high probability of adverse effects (AEs), we assessed AE monitoring for anti-TB drugs in the Health Care System of Kosova.

METHODS

This survey was a cross-sectional analysis performed at the primary, secondary and tertiary health care levels in Kosova. We included 930 registered tuberculosis patients within three levels of this health system in our study. Furthermore, we interviewed 62 physicians and 71 nurses at TB health facilities. Data were collected from official TB registers and personal contact with patients for 12 months.

RESULTS

The representative age group was 19 to 29 years (30.49%), followed by a group of patients aged >60 years (23.23%). Among 930 patients treated with TB drugs, the total incidence of adverse AEs was 29.03%. Female TB patients had a higher rate of AEs than did male patients (33.56% vs 28.84%, respectively). The highest incidence of registered AEs was recorded in the gastrointestinal system (270, 80.83%), followed by the central nervous system (CNS, 7.50%) and was lower in other organ systems. The reporting of anti-TB drug effects by medical staff (TB medical doctor and TB medical nurse) at different levels of TB medical settings occurred among 62.90% of medical doctors and 81.69% of nurses. Only 53.23% of medical doctors and 46.48% of nurses completed pharmacovigilance training.

CONCLUSION

The pharmacovigilance approach in Health System of Kosova is not comprehensible and not systematic. The relatively low incidence of AEs among TB patients is due under reporting of these by medical staff. The knowledge, attitudes, and adherence of medical staff reveal low awareness for pharmacovigilance activities, and this concern should be addressed to reinforce this important issue for the safe treatment of TB patients.

A medicinal chemistry perspective of drug repositioning: Recent advances and challenges in drug discovery

Drug repurposing is a strategy consisting of finding new indications for already known marketed drugs used in various clinical settings or highly characterized compounds despite they can be failed drugs. Recently, it emerges as an alternative approach for the rapid identification and development of new pharmaceuticals for various rare and complex diseases for which lack the effective drug treatments. The success rate of drugs repurposing approach accounts for approximately 30% of new FDA approved drugs and vaccines in recent years. This review focuses on the status of drugs repurposing approach for various diseases including skin diseases, infective, inflammatory, cancer, and neurodegenerative diseases. Efforts have been made to provide structural features and mode of actions of drugs.

Intermolecular hydrogen bond interactions in the thiourea/water complexes (Thio-(H2O)n) (n = 1, …, 5): X-ray, DFT, NBO, AIM, and RDG analyses

This study aims to experimentally and theoretically examine the nature and energy of intermolecular bond interactions between thiourea and water molecules using natural bond orbital (NBO), non-linear optical (NLO), atoms in molecules (AIM), and reduced density gradient (RDG) analyses based on the quantum chemical approach and spectroscopic analysis on X-ray and FTIR. Geometry optimizations of Thio-(H₂O)_1-5 complexes were carried out in the gas phase by B3LYP/6-311++G(d,p) level of density functional theory. The nature of the molecular interactions between the water and thiourea through hydrogen bonding has been investigated using RDG and AIM methods. NBO analysis shows that the Thio-(H₂O)₅ complex has higher stabilization energy values than the other complexes. The non-linear optical properties, such as dipole moment (μ), the polarizability (α₀), and the first hyperpolarizability (β_tot), and thermodynamic functions, such as entropy (S), specific heat capacity (C_v), and thermal energy (E), were calculated using the same method. It was observed that thermodynamic parameters, polarizability, and the first hyperpolarizability increased with the number of water molecules. X-ray diffraction analysis confirmed that thiourea is single crystal, and the thiourea/water complexes are crystalline in nature. Besides, the infrared spectrum shows the existence of water molecules and it is used to get details of the structure of the complex.

Mycobacterial Cell Wall: A Source of Successful Targets for Old and New Drugs

Eighty years after the introduction of the first antituberculosis (TB) drug, the treatment of drug-susceptible TB remains very cumbersome, requiring the use of four drugs (isoniazid, rifampicin, ethambutol and pyrazinamide) for two months followed by four months on isoniazid and rifampicin. Two of the drugs used in this “short”-course, six-month chemotherapy, isoniazid and ethambutol, target the mycobacterial cell wall. Disruption of the cell wall structure can enhance the entry of other TB drugs, resulting in a more potent chemotherapy. More importantly, inhibition of cell wall components can lead to mycobacterial cell death. The complexity of the mycobacterial cell wall offers numerous opportunities to develop drugs to eradicate Mycobacterium tuberculosis, the causative agent of TB. In the past 20 years, researchers from industrial and academic laboratories have tested new molecules to find the best candidates that will change the face of TB treatment: drugs that will shorten TB treatment and be efficacious against active and latent, as well as drug-resistant TB. Two of these new TB drugs block components of the mycobacterial cell wall and have reached phase 3 clinical trial. This article reviews TB drugs targeting the mycobacterial cell wall in use clinically and those in clinical development.

The endTB observational study protocol: treatment of MDR-TB with bedaquiline or delamanid containing regimens

Background

At a time when programs were struggling to design effective regimens for the treatment of multidrug-resistant tuberculosis (MDR-TB), the marketing authorization of bedaquiline and delamanid was a critical development in the MDR-TB treatment landscape. However, despite their availability for routine programmatic use, the uptake of these drugs has remained slow; concerns included a lack of evidence on safety and efficacy and the need to protect the new drugs from the development of acquired resistance. As part of the endTB Project, we aimed to address these barriers by generating evidence on safety and efficacy of bedaquiline or delamanid based MDR-TB regimens.

Methods

This is a protocol for a multi-center prospective cohort study to enroll 2600 patients from April 2015 through September 2018 in 17 countries. The protocol describes inclusion of patients started on treatment with bedaquiline- or delamanid- containing regimens under routine care, who consented to participate in the endTB observational study. Patient follow-up was according to routine monitoring schedules recommended for patients receiving bedaquiline or delamanid as implemented at each endTB site. Therefore, no additional tests were performed as a part of the study. Data were to be collected in a customized, open-source electronic medical record (EMR) system developed as a part of the endTB Project across all 17 countries.

Discussion

The endTB observational study will generate evidence on safety and efficacy of bedaquiline- and delamanid-containing regimens in a large, extremely heterogeneous group of MDR-TB patients, from 17 epidemiologically diverse countries. The systematic, prospective data collection of repeated effectiveness and safety measures, and analyses performed on these data, will improve the quality of evidence available to inform MDR-TB treatment and policy decisions. Further, the resources available to countries through implementation of the endTB project will have permitted countries to: gain experience with the use of these drugs in MDR-TB regimens, improve local capacity to record and report adverse events (pharmacovigilance), and enhance significantly the body of data available for safety evaluation of these drugs and other novel treatments.

Trial registration

This study was registered on 24 August 2017 at clincaltrials.gov (Registration number: NCT03259269).

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4378-4) contains supplementary material, which is available to authorized users.

Identification of acylthiourea derivatives as potent Plk1 PBD inhibitors

Thiourea derivatives have drawn much attention for their latent capacities of biological activities. In this study, we designed acylthiourea compounds as polo-like kinase 1 (Plk1) polo-box domain (PBD) inhibitors. A series of acylthiourea derivatives without pan assay interference structure (PAINS) were synthesized. Four compounds with halogen substituents exhibited binding affinities to Plk1 PBD in low micromole range. The most potent compound (3v) showed selectivity over other subtypes of Plk PBDs and inhibited the kinase activity of full-length Plk1.

Adverse Drug Reaction Reporting in Africa and a Comparison of Individual Case Safety Report Characteristics Between Africa and the Rest of the World: Analyses of Spontaneous Reports in VigiBase®

Introduction

Following the start of the World Health Organization (WHO) Programme for International Drug Monitoring (PIDM) by 10 member countries in 1968, it took another 24 years for the first two African countries to join in 1992, by which time the number of member countries in the PIDM had grown to 33. Whilst pharmacovigilance (PV), including the submission of individual case safety reports (ICSR) to VigiBase^®, the WHO global ICSR database, is growing in Africa, no data have been published on the growth of ICSR reporting from Africa and how the features of ICSRs from Africa compare with the rest of the world (RoW).

Objective

The objective of this paper was to provide an overview of the growth of national PV centres in Africa, the reporting of ICSRs by African countries, and the features of ICSRs from Africa, and to compare ICSRs from Africa with the RoW.

Methods

The search and analysis interface of VigiBase^®—VigiLyze^®—was used to characterise ICSRs submitted by African countries and the RoW. The distribution of ICSRs by African countries was listed and characterised by anatomic therapeutic chemical (ATC) code, Medical Dictionary for Regulatory Activities (MedDRA^®) system organ class (SOC) classification, and patient age and sex. The case-defining features of ICSRs between Africa and the RoW were also compared.

Results

The number of African countries in the PIDM increased from 2 in 1992 to 35 at the end of September 2015, and African PIDM members have cumulatively submitted 103,499 ICSRs (0.88 % of global ICSRs) to VigiBase^®. The main class of products in African ICSRs are nucleoside and nucleotide reverse transcriptase inhibitors (14.04 %), non-nucleoside reverse transcriptase inhibitors (9.09 %), antivirals for the treatment of HIV infections (5.50 %), combinations of sulfonamides and trimethoprim (2.98 %) and angiotensin-converting enzyme (ACE) inhibitors (2.42 %). The main product classes implicated in ICSRs from the RoW are tumour necrosis factor-α (TNFα) inhibitors (5.29 %), topical nonsteroidal anti-inflammatory preparations (2.26 %), selective immunosuppressants (2.08 %), selective serotonin reuptake inhibitors (2.04 %) and HMG CoA reductase inhibitors (1.85 %). The main SOCs reported from Africa versus the RoW include skin and subcutaneous tissue disorders (31.14 % vs. 19.58 %), general disorders and administration site conditions (20.91 % vs. 30.49 %) and nervous system disorders (17.48 % vs. 19.13 %). The 18–44 years age group dominated ICSRs from Africa, while the 45–64 years age group dominated the RoW. Identical proportions of females (57 % Africa and the RoW) and males (37 % Africa and the RoW) were represented.

Conclusions

As at the end of September 2015, 35 of 54 African countries were Full Member countries of the PIDM. Although the number of ICSRs from Africa has increased substantially, ICSRs from Africa still make up <1 % of the global total in VigiBase^®. The features of ICSRs from Africa differ to those from the RoW in relation to the classes of products as well as age group of patients affected. The gender of patients represented in these ICSRs are identical.

Repositioning of Thiourea-Containing Drugs as Tyrosinase Inhibitors

Tyrosinase catalyzes two distinct sequential reactions in melanin biosynthesis: The hydroxylation of tyrosine to dihydroxyphenylalanine (DOPA) and the oxidation of DOPA to dopaquinone. Developing functional modulators of tyrosinase is important for therapeutic and cosmetic purposes. Given the abundance of thiourea moiety in known tyrosinase inhibitors, we studied other thiourea-containing drugs as potential tyrosinase inhibitors. The thiourea-containing drugs in clinical use were retrieved and tested for their ability to inhibit tyrosinase. We observed that methimazole, thiouracil, methylthiouracil, propylthiouracil, ambazone, and thioacetazone inhibited mushroom tyrosinase. Except for methimazole, there was limited information regarding the activity of other drugs against tyrosinase. Both thioacetazone and ambazone significantly inhibited tyrosinase, with IC₅₀ of 14 and 15 μM, respectively. Ambazone decreased melanin content without causing cellular toxicity at 20 μM in B16F10 cells. The activity of ambazone was stronger than that of kojic acid both in enzyme and melanin content assays. Kinetics of enzyme inhibition assigned the thiourea-containg drugs as non-competitive inhibitors. The complex models by docking simulation suggested that the intermolecular hydrogen bond via the nitrogen of thiourea and the contacts via thione were equally important for interacting with tyrosinase. These data were consistent with the results of enzyme assays with the analogues of thiourea.