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.

Pharmacovigilance in resource-limited countries.

In the past 20 years, many low- and middle-income countries have created national pharmacovigilance (PV) systems and joined the WHO's global PV network. However, very few of them have fully functional systems. Scientific evidence on the local burden of medicine-related harm and their preventability is missing. Legislation and regulatory framework as well as financial support to build sustainable PV systems are needed. Public health programs need to integrate PV to monitor new vaccines and medicines introduced through these programs. Signal analysis should focus on high-burden preventable adverse drug problems. Increased involvement of healthcare professionals from public and private sectors, pharmaceutical companies, academic institutions and the public at large is necessary to assure a safe environment for drug therapy. WHO has a major role in supporting and coordinating these developments.

The monitoring medicines project: a multinational pharmacovigilance and public health project.

The Monitoring Medicines project (MM), funded by the FP-7 EU framework, was carried out between 2009 and 2013 by a consortium of 11 partners. The objectives were to support and strengthen consumer reporting of adverse drug reactions (ADRs); expand the role and scope of national pharmacovigilance centres concerning medication errors; promote improved use of pharmacovigilance data; and develop methods to complement spontaneous reporting. The work was organised into four themes: patient reporting; medication errors; drug dependence, counterfeit and substandard medicines and clinical risk estimation; and active and targeted spontaneous pharmacovigilance. MM differed from some other major pharmacovigilance initiatives by having participants from developing countries in Asia and Africa and in leaning towards public health and communicable diseases. MM brought together stakeholders including WHO, drug regulators, pharmacovigilance centres, consumers, public health and disease specialists and patient safety networks. Resources and methodologies developed directly by, or with support from, MM include electronic systems/tools for consumer ADR reporting and cohort event monitoring; publication by WHO of handbooks on consumer reporting, medication errors and pharmacovigilance for TB medicines; methodologies for detecting drug dependence and substandard or counterfeit medicines in ADR databases; and a database on HIV treatment risks with a risk assessment tool. MM enabled stakeholders to achieve more than if they had worked alone in pursuit of patient safety.

WHO strategy for collecting safety data in public health programmes: complementing spontaneous reporting systems.

Globally, national pharmacovigilance systems rely on spontaneous reporting in which suspected adverse drug reactions (ADRs) are reported to a national coordinating centre by health professionals, manufacturers or patients. Spontaneous reporting systems are the easiest to establish and the cheapest to run but suffer from poor-quality reports and underreporting. It is difficult to estimate rates and frequencies of ADRs through spontaneous reporting. Public health programmes need to quantify and characterize risks to individuals and communities from their medicines, to minimize harm and improve use, to sustain public confidence in the programmes, and to track problems due to medication errors and poor quality medicines. Additional methods are therefore needed to monitor the quantitative aspects of medicine safety, to better identify specific risk factors and high-risk groups, and to characterize ADRs associated with specific medicines and in specific populations. The present paper introduces two methods, cohort event monitoring and targeted spontaneous reporting, that are being implemented by the WHO, in its public health programmes, to complement spontaneous reporting. The advantages and disadvantages of these methods and how each can be applied in clinical practice are discussed.

Specific features of medicines safety and pharmacovigilance in Africa.

The thalidomide tragedy in the late 1950s and early 1960s served as a wakeup call and raised questions about the safety of medicinal products. The developed countries rose to the challenge putting in place systems to ensure the safety of medicines. However, this was not the case for low-resource settings because of prevailing factors inherent in them. This paper reviews some of these features and the current status of pharmacovigilance in Africa. The health systems in most of the 54 countries of Africa are essentially weak, lacking in basic infrastructure, personnel, equipment and facilities. The recent mass deployment of medicines to address diseases of public health significance in Africa poses additional challenges to the health system with notable safety concerns. Other safety issues of note include substandard and counterfeit medicines, medication errors and quality of medicinal products. The first national pharmacovigilance centres established in Africa with membership of the World Health Organization (WHO) international drug monitoring programme were in Morocco and South Africa in 1992. Of the 104 full member countries in the programme, there are now 24 African countries with a further nine countries as associate members. The pharmacovigilance systems operational in African countries are based essentially on spontaneous reporting facilitated by the introduction of the new tool Vigiflow. The individual case safety reports committed to the WHO global database (Vigibase) attest to the growth of pharmacovigilance in Africa with the number of reports rising from 2695 in 2000 to over 25,000 in 2010. There is need to engage the various identified challenges of the weak pharmacovigilance systems in the African setting and to focus efforts on how to provide resources, infrastructure and expertise. Raising the level of awareness among healthcare providers, developing training curricula for healthcare professionals, provisions for paediatric and geriatric pharmacovigilance, engaging the pharmaceutical industries as well as those for herbal remedies are of primary concern.

Pharmacovigilance activities in 55 low- and middle-income countries: a questionnaire-based analysis.

BACKGROUND: The WHO Programme for International Drug Monitoring aims to develop a comprehensive global pharmacovigilance strategy that responds to the healthcare needs of low- and middle-income countries. However, first there is a need to measure and understand existing conditions and pharmacovigilance initiatives intended in these settings. Very few investigations have carried out such a systematic assessment of the pharmacovigilance landscape in recent years in low- and middle-income countries. OBJECTIVE: To assess current and planned pharmacovigilance activities in low- and middle-income countries, identify gaps and the most urgent pharmacovigilance priorities at national and international levels, and define the elements of a sustainable global pharmacovigilance strategy. METHODS: A standardized questionnaire was sent to 114 representatives of countries participating in the WHO Programme for International Drug Monitoring (but excluding Australia, Canada, New Zealand, Switzerland and the International Conference on Harmonization countries, i.e. countries in Europe, Japan and the US) and to a few other identified contacts from non-member countries. The questionnaire was sent out between March and July 2008 and was designed to collect information on the structure, resources, functions and achievements of pharmacovigilance systems in low- and middle-income countries, with a focus on pharmacovigilance activities supported by national health authorities including public health programmes. All questionnaires that were returned by the end of July 2008 were used in the analysis. RESULTS: Fifty-five completed questionnaires were received by July 2008, representing a response rate of 55.5%. Forty-five percent of the pharmacovigilance centres in the analysis were established during the 1990s and 49% were set up later; 69% were affiliated with their Drug Regulatory Agency, 20% with the Ministry of Health and 9% with a university or other scientific body. Few countries (23 of 55) have any budget allocated for pharmacovigilance. Public health programmes (44%), the Global Fund to fight AIDS, Tuberculosis and Malaria (36%), universities (26%), poison centres (21%), Management Sciences for Health (18%) and Rational Use of Drugs networks (15%) sponsor some pharmacovigilance activities. In addition to direct pharmacovigilance activities, many centres are also involved in other activities such as drug information (63%), promoting patient safety (52%), rational use of drugs (46%) and poison information (15%). Some countries have sentinel sites to monitor HIV/AIDS patients (in seven countries) and other special groups. Information gathered through pharmacovigilance activities is used to assist regulatory functions in most countries (n = 42), lack of training and funding were mentioned as being major challenges to pharmacovigilance in many countries. CONCLUSIONS: This study has helped identify some of the special challenges and barriers to promoting pharmacovigilance in low- and middle-income countries. A pharmacovigilance strategy in these settings needs to help build health systems that can serve the purpose of multiple health conditions. It needs to identify and implement feasible systems, governance, infrastructures, human resource, training and capacity building, sustainable methodologies and innovations in pharmacovigilance; a key component will be the dissemination of medicines safety information to policy makers and regulators and knowledge sharing with healthcare professionals through high quality informatics and learning tools, with rational use of medicines and patient safety as the ultimate goal of pharmacovigilance.

Effect of combined treatment of thioperamide with some antiepileptic drugs on methionine-sulfoximine induced convulsions in mice.

Methionine-sulfoximine (MSO), a convulsant is known to increase the activity of histamine N-methyl transferase. The effect of a selective H3 receptor agonist R- (alpha) methylhistamine (RAMH) and antagonist (thioperamide, THP) and some antiepileptic drugs (gabapentin and sodium valproate) have been evaluated on MSO-induced convulsions in mice. The effect of THP was also evaluated in combination with these antiepileptic drugs. Sodium valproate (300 mg/kg, po) and gabapentin (400 mg/kg, po) offered protection against MSO-induced convulsions as evidenced by a significant prolongation of latency to abnormal dorsoflexion and complete protection against mortality within 6 h of administration. THP (15 mg/kg, ip) alone and in combination with sub-effective doses of gabapentin (75 mg/kg, po) and sodium valproate (75 mg/kg, po) revealed no significant differences from the control group or either drug alone. Hence, the convulsant action of MSO does not appear to be mediated via histaminergic mechanisms.

Thioperamide reduces intracellular calcium in mouse brain synaptosomes.

Intracellular calcium regulation is vital for cells, especially for neurons; raised levels are associated with cytotoxicity and neuronal death. In this report, we present the first experimental evidence showing a concentration-dependent reduction of free calcium in the mouse brain synaptosomes by thioperamide (THP), an H3 receptor antagonist. This is interesting in view of the recent reports on the anticonvulsant and cognition facilitating effects of THP. A neuroprotective potential of THP is suggested.

Modulation of spontaneous alternation performance of mice treated with thioperamide and tacrine in a cross maze task.

A combination of sub-effective doses of thioperamide (7.5 mg/kg, i.p.) and tacrine (0.5 mg/kg, i.p.) enhanced performance in a spatial memory task in mice. This was shown by a significant increase in their spontaneous alternation scores in a cross maze test.

Effects of folic acid and lamotrigine therapy in some rodent models of epilepsy and behaviour.

It has been suggested that a folic acid (FA) deficiency induced by antiepileptic drugs might be the basis for the neuropsychiatric toxicity associated with these drugs. In the present study, lamotrigine (LTG), one of the newer antiepileptic drugs, was evaluated for its effect on epilepsy, mood and memory in mice. Further, the effect of the addition of FA to LTG therapy was also investigated. The increasing current electroshock seizure test was used to evaluate the anticonvulsant effect of drugs, while the forced swimming test (FST) and spontaneous alternation behaviour (SAB) models were employed for assessing the effects on mood and memory, respectively. LTG exhibited a dose-dependent increase in seizure threshold, whereas FA did not have any effect. LTG did not affect, whereas FA decreased, behavioural depression in the FST in mice. Neither LTG nor FA affected memory scores in the SAB test. The combination of LTG and FA significantly reduced depression while enhancing the effects on memory and seizure threshold. The present observations have confirmed the antiepileptic action of LTG in yet another rodent model of epilepsy. Further, the results clearly demonstrate the additional benefits on epilepsy, mood and memory brought about by the inclusion of FA in the LTG regimen.

Effects of gabapentin and antidepressant drug combinations on convulsions and memory in mice.

In epileptic patients, neurobehavioral problems such as cognitive impairment, depression, and psychosocial impairments have been described, which may have a pathological and/or iatrogenic basis. For this reason additional treatment is required, beside antiepileptic drug (AED) therapy, to correct the accompanying neurological deficits. However, the rationale behind use of antidepressants along with antiepileptics has been questioned due to proconvulsant effects of the former. In the present study, the effect of gabapentin (GBP) on seizure score and memory is evaluated when it is given alone and in combination with some antidepressants, such as sertraline (SERTR) and alprazolam (ALP). Pentetrazole (PTZ)-induced convulsion and spontaneous alternation behavior (SAB) models were used to study the anticonvulsant effect and effect on memory, respectively. Results showed that addition of SERT to GBP or ALP resulted in reduction of anticonvulsant efficacy of these drugs. However, the combination of GBP + SERT + ALP was superior as far as effect on seizure severity and memory was concerned.

Competition between memory systems: acetylcholine release in the hippocampus correlates negatively with good performance on an amygdala-dependent task.

Lesions of the amygdala impair acquisition of a food conditioned place preference (CPP) task. In contrast, lesions of the fornix facilitate acquisition on this task, showing that an intact hippocampal system can interfere with learning an amygdala-dependent task. Our recent findings indicate that acetylcholine (ACh) release in the hippocampus increases while rats perform a hippocampus-dependent spontaneous alternation task. To the extent that ACh output in the hippocampus reflects activation of that brain area in learning and memory, the results obtained with fornix lesions suggest that ACh release in the hippocampus might be negatively correlated with learning on a CPP task. Using in vivo microdialysis, release of ACh was measured in the hippocampus while rats learned and were tested on an amygdala-dependent CPP task and a hippocampus-dependent spontaneous alternation task. Release of ACh in the hippocampus increased when rats were tested on either task. The magnitude of the increase in release of hippocampal ACh was negatively correlated with good performance on the amygdala-dependent CPP task. These findings suggest that ACh release may reflect activation and participation of the hippocampus in learning and memory, but in a manner that can be detrimental to performance on a task dependent on another brain area.