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Pharmacovigilance
 

Pharmacovigilance

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    Pharmacovigilance Pharmacovigilance Presentation Transcript

    • PharmacovigilanceClinical Pharmacology SeminarDepartment of Pharmacology and Toxicology,Faculty of Pharmacy, Comenius UniversityNov 2009 Vladimir Patras, PharmD, MBA
    • Withdrawn Drugs (in the US, since 2000) Drug Year Reason Lumiracoxib 2008 Hepatotoxicity Aprotinin 2008 Kidney and cardiovascular toxicity Tegaserod 2007 Cardiovascular ischemic events Ximelagatran 2006 Hepatotoxicity Valdecoxib 2005 Dermatology adverse events Pemoline 2005 Hepatotoxicity Rofecoxib 2004 Thrombotic cardiovascular events Levomethadyl 2003 Fatal Arrhytmia Rapacuronium 2001 Risk of fatal bronchospasm Cerivastatin 2001 Rhabdomyolosis Trovafloxacin 2001 Hepatotoxicity Amineptine 2000 Hepatotoxicity, dermatological side effects, abuse potential Cisapride 2000 Cardiac arrhythmias Troglitazone 2000 Hepatotoxicity Other drugs were restricted in use to exclude some patient populations or indications - Alosetron Some drugs were withdrawn and reintroduced after further studies or special safety measures – Natalizumab withdrawn in 2005 and reintroduced in 2006
    • Do You Know ? Number of deaths resulting from medical errors in the US may be 100 000 per year. Medical errors are among leading causes of death (4th - 6th) – more prevalent then motor vehicle accidents. 5 % of all deaths may be caused by pharmaceuticals. Medical errors lead to excess costs ($ 37 B/year in the US), health injury Medical errors are preventable in large scale (at least in 50 %) but in some cases new approaches are needed
    • It Should be Recognized Each drug has its side effects Pharmacological/toxic effect frontier is only defined by dose quantity and may differ from patient to patient. Theoretically each drug can be toxic. There are efficient mechanisms how to tackle both expected and unexpected adverse drug reactions. Medicines safety is principal task of regulatory agencies.
    • What is Pharmacovigilance ? Data gathering related to the detection, assessment, understanding, and prevention of adverse events Identifying new information about hazards associated with medicines, preventing harm to patients Post-marketing surveillance (?) Medical errors are broader category which includes adverse reactions but also other factors (diagnostic errors, equipment failure, nosocomial infections ... )
    • Terms Adverse Event (AE) – any untoward medical occurrence that may present during treatment with a pharmaceutical product but which does not necessarily have a casual relationship with this treatment Adverse Drug Reaction (ADR) – a response to a drug which is noxious and unintended, and which occurs at doses normally used in man. Serious Adverse Event (SAE) – AE that is either life- threatening, fatal, cause of prolong hospital admission, cause persistent disability or concern misuse or dependence
    • Terms Serious Adverse Drug Reaction (SADR) – ADR where SAE conditions of severity applies Unexpected Adverse Drug Reaction (UADR) – an adverse reaction, the nature or severity of which is not consistent with market authorization, or expected from the characteristics of the drug.
    • Terms Signal – reported information on a possible relationship between an adverse event and a drug, unknown or incompletely documented previously. Usually more than a single report is required to generate a signal, depending upon the seriousness of the event and the quality of the information
    • Expected and Unexpected Adverse Reactions Expected are those adverse reactions that were observed during clinical trials or post-approval observations and are mentioned in Summary of Product Characteristics (SPC) Unexpected are those adverse events that were not previously observed and are not documented (in SPC) Based on frequency of occurrence there are following categories of adverse events: Category Frequency Very common ≥ 1/10 Common ≥1/100 and <1/10 Uncommon ≥ 1/1,000 and <1/100 Rare ≥ 1/10,000 and <1/1,000 Very rare < 1/10,000
    • Avandia (Rosiglitazone) Adverse Reactions - SPC
    • Types of Adverse Reactions (Rawlins and Thompson Classification)Type A Effects (“Augmented”) Due to pharmacological effects Are dose related – may often be avoided by using doses which are appropriate to the individual patient Are common, can be experimentally reproduced, known before marketing Example: hypnotic effect after H2 antihistaminics
    • Types of Adverse Reactions (Rawlins and Thompson Classification)Type B Effects (“Bizzard”, idiosyncratic reactions) Generally rare and unpredictable Little or no dose relationship, not related to drug pharmacodynamics Occur in predisposed, intolerant patients – can be explained by rare genetic polymorphism, allergic reactions Example: Penicilline allergies
    • Types of Adverse Reactions (Rawlins and Thompson Classification)Type C Effects (“Continuous”) Adverse reactions after long term therapy There is often no suggestive time relationship and the connection may be very difficult to prove. The use of a drug increases the frequency of “spontaneous” disease Example: carcinogenesis
    • Types of Adverse Reactions (Rawlins and Thompson Classification)Type D Effects (“Delayed”) Adverse effect may be presented years after a drug was used Example: Vagina cancer of daughters when their mother was treated by diethylstilbestrolType E Effects (“Ending”) Absence of drug after withdrawal – rebound effect Example: corticosteroids in asthma treatment
    • Causality AssessmentTo determine likelihood of a causal relationship between drug exposure and adverse events it is necessary to evaluate − Association in time/place between drug use and event − Pharmacology (including current knowledge of nature and frequency of adverse reactions) − Medical or pharmacological plausibility (signs and symptoms, tests, pathological findings, mechanism) − Likelihood or exclusion of other causes(Case reports describe suspected ADRs)
    • Causality Assessment There are more assessment scales for causality evaluation which include: − Karch and Lasagna scale − Naranjo scale − WHO probability scale − Jones scaleKarch and Lasagna Uses three categories of causality − A – causality is highly probable − B – not adequate proof of causality − 0 – data are not adequate to assess causality
    • Causality AssessmentNA RANJOs ALGORITHMquestion Yes No Dont knowAre there previous conclusion reports on this reaction? +1 0 0Did the adverse event appear after the suspect drug was administered? +2 -1 0Did the AR improve when the drug was discontinued or a specific +1 0 0antagonist was administered?Did the AR reappear when drug was readministered? +2 -1 0Are there alternate causes [other than the drug] that could solely have -1 +2 0caused the reaction?Did the reaction reappear when a placebo was given? -1 +1 0Was the drug detected in the blood [or other fluids] in a concentration +1 0 0know n to be toxic?Was the reaction more severe when the dose was increased, or less +1 0 0severe when the dose was decreased?Did the patient have a similar reaction to the same or similar drugs in any +1 0 0previous exposure?Was the adverse event confirmed by objective evidence? +1 0 0
    • Classification of Adverse Events Based on its Severity Mild – no changes in therapy are needed Moderate – change of therapy is desired but the events are not life-threatening or causing disability Serious – is either life-threatening, fatal, cause of prolong hospital admission, cause persistent disability
    • Pharmacology in Adverse Reactions Detailed safety profile of a drug can only be evaluated and described on base of clinical research and postmarketing surveillance However, there are some factors that can be associated with higher safety risks. These risk can be on side of: − Administered drug − Patient − Environment (xenobiotics, physical conditions) Higher safety risks are associated with medicines with no specific mechanism of action such as neuroleptics (haloperidol, chlorpromazine), non-selective cyclooxygenase inhibitors, cytostatics, morphine analgetics Another group is medicines with narrow therapeutic range (i.e. low therapeutic index) – cardiac glycosides, aminoglycoside antibiotics (gentamycin), theophylline Therapeutic index = Median Toxic Dose (TD50)/ Median Effective Dose (ED50)
    • Risks Dependent on Patient Kidney insufficiency – failing excretion of drugs/active metabolites Liver disease – failing drug metabolism Polymorbidity – combination of factors such as drug interactions, multi-organ injury Immunocompetence – higher doses of some drugs (antibiotics) may be needed in decreased immune response New born age – drug metabolizing systems are not fully developed Allergies – risk of drug allergies is higher in patients with already suffer from another allergy Some specific diseases – such as contraindication of beta blockers in asthma
    • Pharmacogenetics Study of how individual`s genetic inheritance affects response to drugs Genetic polymorphisms in metabolizing enzymes can cause substantial differences in drug response. Some polymorphisms are very rare Genetic testing was developed to detect various polymorphisms in metabolizing enzymes (CYP 450) – this opens possibility of personalized prescribing to avoid adverse eventsImportant enzymes in drug metabolism with more known polymorphisms Cytochrome P450 polymorphisms – influence metabolism of various drugs Thiopurine Methyltransferase (TMT) – metabolism of thiopurines AcetyltransferasesAnother mechanism is interaction with Human Leukocyte Antigen system (HLA ) - klozapin, levamizol, carbamazepine
    • Risks Dependent on Other FactorsDrug dependent Drug interactionsEnvironment dependent Xenobiotics (pesticides, veterinary antibiotics) can interact with drugs metabolism, most commonly on CYP 450 level
    • Classification of Adverse EventsAdverse events can be roughly classified on base of its underlying mechanism, although this classification is not unambiguous and there are disputable cases to which category an event can be attributed Intolerance – lower then usual dose produce anticipated response Idiosyncratic (“unusual”) response – determined by genetic alteration, producing response that is not anticipated Allergy – response modulated by immune system Pseudoallergy – reaction similar to allergy but not mediated by immune system
    • System of Safety Data Gathering Clinical Trials Healthcare Professionals Pre-Approval Post-Approval National Regulatory Patients Authority Pharmaceutical Companies International Safety Databases
    • New Drug Approval Process  Each new drug (New Chemical Entity, NCE) shall prove its safety and efficacy in order to gain marketing authorization  Scientific data on efficacy/safety are collected in clinical trials  If a drug meets all safety (and efficacy) requirements New Drug Application (NDA) is submitted to regulatory agency  Regulatory agency reviews the application, may require further studies. It issues Marketing Authorization (MA) or reject application, guided by risk/benefit evaluation  Research of drug safety continues after drug is introduced in clinical praxis as post-marketing surveillance (phase IV study)
    • Cerivastatin Case Study Cerivastatin was developed by Bayer to compete with other statins. Rhabdomyolysis cases were rare in other statins (3.3 per 100 000 patient- years). Cerivastatin gained US marketing authorization in June 1997 as cholesterol lowering agent and cardiovascular disease prevention. It was introduced to US market in early 1998 under brand names Baycol and Lipobay. Soon after (until May 1998) Bayer received 6 SADRs of cerivastatin associated rhabdomyolysis in patients also taking gemfibrozil. This was followed by label update – rhabdomyolysis warning. First case of rhabdomyolysis associated with cerivastatin-gemfibrozil combination published in April 1999. July 1999 - Clinical trial of 1.6 mg cerivastatin reveals high incidence of severe CK elevation (12 %) but the results are not published. Gemfibrozil-cerivastatin coprescription is contraindicated in December 1999
    • Cerivastatin Case Study By 2000, 549 cases of rhabdomyolysis associated with cerivastatin use has been reported to WHO Collaborating Centre in Uppsala Higher risk compared to other statins was admitted by Bayer in March 2000 Label update of April 2001 stated 0.4 mg as starting dose (it became clear that higher doses are associated with higher elevated CK levels) That time Bayer performed study on the risk of myopathy. This study was later criticized because of its poor design but results has not been published. The final report was provided to the company in June 2001. Bayer voluntarily withdraws cerivastatin worldwide on August 8th 2001 FDA publish research in 2002 which found mortality rates from rhabdomyolysis for cerivastatin users were 16 to 86 times higher than those of other statins. However, rhabdomyolysis asscociated with cerivastatin was found to be 270 cases per 100 000 patient-years (most cases were not fatal) in patients taking 0.4 mg cerivastatin. Bayer faced approx. 8000 lawsuits in connection to Baycol/Lipobay
    • Who Regulates Drug Safety Slovakia – State Institute for Drug Control, Section of Drug Safety and Clinical Trials Czech Republic - State Institute for Drug Control, Pharmacovigilence department UK – Medicines and Healthcare Products Regulatory Agency, Vigilence Risk Management of Medicines USA – Food and Drug Administration, Center for Drug Evaluation and Research
    • International Cooperation in Drug Safety EudraVigilence – data processing network for reporting and evaluating suspected adverse reactions of medicinal products in European Economic Area WHO Monitoring Centre in Uppsala − Established in 1978 − Coordination of the WHO programme for International Drug Monitoring − Collection, processing of data, Education, Research
    • Sources of Information on Drug Safety Pre-clinical studies Clinical trials (pre- and post-marketing) Spontaneous adverse reaction reporting Epidemiological studies Data collected for other purposes − Routine statistics − Databases of prescription and outcomes
    • Pre-clinical StudiesStandard toxicology pre-clinical tests are: Acute toxicity Repeat use toxicity Local irritation tests Pyrogenity Reproductive toxicity Mutagenity Carcinogenity
    • Clinical Trials Principal aim of clinical is to collect safety (and efficacy) data. The investigational drug shall prove safety profile consistent with human testing on base of pre-clinical studies. Clinical trials are subject of regulatory approval. The sponsor shall keep detailed records of all adverse events and he shall submit these records on request of regulatory authority. The sponsor shall ensure that all relevant information about suspected serious unexpected adverse reactions have to be recorded and reported to regulatory authority Other investigators participating in multicentric trials shall also be informed on serious unexpected adverse events
    • Clinical Trials Safety profile of investigational drug is described in Investigator`s Brochure (likewise SPC in marketed drugs Procedures for reporting of adverse events in clinical trials slightly differ from post-approval reporting. Standard are CIOMS forms, electronic reporting is now preferred Detailed guidance on the collection, verification and presentation of adverse reactions reports arising from clinical trials on medicinal products for human use, European Commission, April 2006 Serious events such as deaths are relatively rare and may present reason for termination of a clinical trial
    • Rationale for Post-Marketing Surveillance Tests in animals are insufficient to predict human safety In clinical trials patients are selected and limited in number Conditions of use in trials differ from those in clinical practice Duration of trials is limited Information about rare but serious adverse reactions, chronic toxicity, use in special groups such as children, the elderly or pregnant woman or drug interactions is often not available
    • Who Should Report Safety Data Physicians Pharmacists Pharmaceutical companies qualified persons – (Pharmacovigilence/Regulatory manager) − Investigational products (clinical trials) − Post-approval reporting – Individual Case Safety Report (ICSR), Periodic Safety Update Report (PSUR) In many countries patients are encouraged (but not obligated) to report side effects
    • What to Report – WHO Recommendations Every single problem related to the use of a drug, because probably nobody else is collecting such information All suspected adverse reactions ADRs associated with radiology contrast media, vaccines, diagnostics, drugs used in traditional medicine, herbal remedies, cosmetics, medical devices and equipment Lack of efficacy and suspected pharmaceutical defects Counterfeit pharmaceuticals Development of resistance
    • What to Report (at least) Requirements for reporting differ from country to country. However, in each developed country healthcare professionals are legally obligated to report adverse reactions (although it is not always clearly stated which) It is important to report serious unexpected ADRs – those that are not described in SPC. Unexpected include also side effects mentioned in SPC when these occur in higher frequencies then described. Most cases of unexpected ADRs are associated with medicines newly introduced on the market It has no sense to report expected adverse In clinical praxis it is usually not easy to evaluate causality – report also in cases you are not sure about causal relationship Heathcare professionals may report adverse events also to marketing authorization holder for a medicine but are not obligated to
    • How to Report - Slovakia SPRÁVA O NEŽIADUCOM ÚČINKU LIEKU Iniciálky pacienta:: Dátum nar.: Sex: muž - žena Dát um nežiaducej reakcie:.................................................. Nežiaduce reakcie: Guidance No. 15/2004 on reporting 1................................…................................... 4.................................................................. of side effects of registered 2...................................................................... 3...................................................................... 5.................................................................. 6.................................................................. medicines Vznikla reakcia u hospitalizovaného áno - nie pacienta? hospitalizácia pre Form downloadable from SIDC site o predĺženie hospitalizácie? NÚL? bol ohrozený život o trvalé poškodenie pacienta? http://www.sukl.sk pacienta? umrel pacient? Dátum úmrtia: Príčina smrti: Podozrivý liek: Podanie Dávka od - do Diagnóza Heathcare professional are 1 Ostatné obligated to report suspected lieky 2 adverse drug reactions with 3 4 presumed casual relationship 5 6 7 In 2004 there were about 900 8 reports mostly from physicians. 9 Prestal sa liek podávať? áno-nie Number of reports is significantly Upravila sa reakcia po vynechaní lieku ? Objavila sa reakcia po novom podaní ? áno- nie- neviem áno- nie- neviem- nepodal sa lower compared to other EU Používal pacient liek v minulosti? áno - nie - neviem countries Anamnéza: o NÚL na lieky? Aké ? o alergia? o fajčenie? o tehotenstvo? o alkohol, drogy Je správa z klinickej skúšky? áno - nie z epidemiol. štúdie? áno - nie Odbornosť lekára: nemocničný lekár? áno - nie Meno lekára: Adresa zariadenia:
    • How to Report - UK “YellowCard Scheme” - established in 1964 MHRA operates site http://yellowcard.mhra.gov.uk/ for reporting of adverse drug reactions Reporting by post is also possible Both patients and healthcare professionals are encouraged to report all suspected adverse drug reaction. MHRA evaluates whether risk is serious and whether there is a causality. Pharmacies are encouraged to display poster on YellowCard and mention it to patients who may experience ADRs when giving advice MHRA provides yellow card to patients (distributed also thru pharmacies) with information on reporting. Pharmacists are considered to be crucial in informing patients on ADRs reporting
    • Content of Report (MHRA recommendations) The symptoms or a description of a side effect Information about the person who experiencedthe side effect (as a minimum, their initials, sex,and age at the time of side effect) The name of the medicine(s) thought to havecaused the side effect The name and full address of the reporter sothat the report can be acknowledged and contactmade for further information, if neccessary.
    • Reporting Requirements for Marketing Authorization Holders (Pharmaceutical Companies) The Marketing Authorization Holder (MAH) should ensure that h has an appropriate system of pharmacovigilance in place in order to assume responsibility and liability for his products on the market and to ensure that appropriate action may be taken when necessary. MAH should therefore ensure that all information relevant to the risk-benefit balance of a medicinal product is reported to the Competent (Regulatory) Authorities and European Medicines Agency fully and promptly in accordance with the legislation Qualified Person Responsible for Pharmacovigilance MAH submit Periodic Safety Update Report (PSUR) for drugs marketed for less than five years. − Submitted in 6 months intervals after MA, once per year two years after MA, then 3-yearly intervals or upon request of regulatory authority − Presentation, analysis and evaluation of new or changing safety data − Sources of data include: spontaneous reports, scientific literature, warning received from other regulatory authorities worldwide, data from special registries, poison control centers and others
    • Safety Data Access http://www.mhra.gov.uk/Safetyinformation/index.htm MHRA publish detailed report for most of registered drugs summarizing nature of adverse events
    • Regulatory Actions Safety warnings Labeling change/changes in SPC Withdrawal
    • Special Cases for Pharmacovigilence Some groups of medicinal products are not required to document their safety – natural medicines, homeopathic preparationsNatural (herbal) medicines Exact composition is often not known, efficacy nor safety is usually not documented Marketing Authorization is granted on base of “traditional use” 37 ADR reports in Australia related to Echinacea use in allergyHomeopathic preparations Zycam Cold Remedy case – unusual dilution resulted in permanent loss of smell in several subjects and 340 filed and settled lawsuits Content of alcohol in some preparations for children is higher than allowed in allopathic medicines
    • Special Cases for Pharmacovigilence Medical Devices – regulated by State Institute for Drug Control. Slightly different reporting requirements – in competence of Medical devices department, particular reporting guidance Veterinary products – competent (regulatory) authority in Slovakia is Institute for State Control of Veterinary Biologicals and Medicaments based in Nitra. Veterinary legislation and marketing requirements are in many aspects similar to human medicines. EMEA is competent authority for veterinary products on European level. Nutritional Supplements – are considered to be special purpose nutrients. Basic safety but not efficacy proof is required for marketing authorization. Regulated in Slovakia by National Health Authority of the Slovak Republic (NHA SR). NHA SR regulates also cosmetic products
    • Disputable and Unresolved Issues Regulatory agencies are now under much more public attention then they used to be ~10 years ago. Affairs such as Vioxx, Lipobay withdrawals attracted public attention and FDA criticism. FDA approach is considered to be more cautious now More stringent approach of regulatory bodies has not always been welcomed – there are claims that absence of some unapproved medicines on the market caused more harm then would be caused by its side effects Some countries lack recourses to establish pharmacovigilance systems. WHO provides some assistance in establishing pharmacovigilance systems in developing countries
    • How to Deal with Expected Adverse Reactions and Medical Errors Focus on medical errors has increased in recent Complex solutions and system approach New concepts of quality management in healthcare – application of knowledge from other industries It is expected that most errors are on level of diagnosis/prescribing and only about 15 % in dispensing of medicines
    • Potential Sources of Errors in Pharmaceutical Care Handwriting of prescriptions Prescribing doctors missing information on other prescriptions for a patient (drug interactions) Similar-sounding and look-alike names and packages of medication Level of stress on workplace Unclear records in information system Bad system of stock alignment/organization Disruptions in information availability and flow
    • Solutions It is expected that 50 – 75 % of medical errors are preventable Introduction of advanced medical information systems − Electronic Health Record (EHR) − Automatic checks for dose, interactions, allergies, resistance − Personalized prescription (on base of pharmacogenetic data) Written procedures, quality management and safety audits Analyze all errors, research what enabled them Try to design uncomplicated processes
    • Personal responsibility (?)Trial with Zheng Xiaoyu, former director of State Food and Drug Administration of China, Beijing Intermediate Court, May 29, 2007Zheng Xiaoyu was convinced of taking bribes for enabling approval of unsafe medicinal products. He was executed on July 10, 2007
    • Where to find information Monographies/Compendia − Davies: Textbook of adverse effects − Dukes: Meyler`s side effects of drugs Journals − Regulatory Toxicology and Pharmacology Newsletters − Drug Safety Update – published by MHRA Regulatory Agencies − FDA: http://www.fda.gov/ − EMEA: http://www.emea.europa.eu/ − SIDC: http://www.sukl.sk
    • Thank You For Your Attention !