A prospective observational study to identify and evaluate the adverse drug reactions among patients on anti-tubercular medications

Tuberculosis (TB) is a major factor for numerous death cases occurring worldwide. World health Organization (WHO) in the year 2016 reported 10.4 million cases of TB globally. A total of seven countries account for 67% of the new cases, out of which India ranks the highest among all with estimated incidence of 2.79 million cases of TB for India.Treatment of tuberculosis has always been a challenge for the health care providers among the developing country. The disease is curable and can be treated with regimen of combination of drugs. Success of TB health program depends upon the completion of course of therapy by the patients. An incomplete course of anti-tubercular therapy renders them infective and eventually leads to development of dug resistance.Factors responsible for modification or discontinuation of treatment includes the longer duration of therapy, adverse drug reactions, drug interactions and unawareness of the disease. Exposure of an individual infected with TB to several combination of drugs for prolonged duration predisposes them to develop drug toxicity. A toxic effect to an anti-TB drug can manifest as mild reaction to fatal life threatening one.A development of adverse drug reaction in the due course of therapy is responsible for poor patient compliance, treatment failure, increased cost and eventually development of drug resistance.With the revision of RNTCP guidelines in 2016 preferring daily treatment to intermittent regimen, the incidence of ADRs are likely to increase. Multidrug-resistant tuberculosis (MDR) is resistance to first line drugs (Isoniazid and Rifampicin) and Extensively drug-resistant tuberculosis (XDR) is MDR TB with additional resistance to any fluoroquinolone and to at least one injectable second-line drugs. With a progressive rise in number of MDR and XDR tuberculosis cases in India, the numbers are expected to double up by 2040 if not intervened at the earliest. Treatment of drug resistance TB with second line agents makes it furthermore challenging as drugs are more toxic, prolonged therapy, poor response rates eventually responsible for rise in morbidity and mortality among the infected population. With the introduction of new drugs, new targets and compounds for treating all forms of tuberculosis, it has raised more severe concern in terms of monitoring, surveillance for effectiveness and drug reactions. The major challenge includes diagnosis and monitoring of these adverse drug reactions, identification of the suspect drug or drugs and selection of subsequent course of therapy.

Pharmacovigilance (PV) is the science and activities related to the detection, assessment, understanding and prevention of adverse effects or other drug-related problems. Spontaneous reporting of ADR is important part of pharmacovigilance program. RNTCP-NTEP strives to improve outcomes for its patients by implementing Pharmacovigilance Program of India (PVPI) for monitoring, identification and detection of signals. This will be a necessary feedback mechanism to regulators and RNTCP at regular intervals.

The study will be initiated after Institutional ethics committee approval and the data collection for the study and interviews will be done after obtaining the consent from the patients using informed consent form. Participants with age more than 18 years, meeting the required inclusion criteria and willing to give informed consent will be included.Patient is diagnosed with TB and is a registered case. When the patient is put on ATT for the first time he/she is also given a flyer explaining the common adverse effects of the drugs written in the local language.

The data collection will be mainly two fold. The patient will be given a card every time he comes to collect his medication from the DOTS centre or when the health worker visits the patient to give the medicines. The patient or a family member will have to fill up if he finds any difficulty while taking the drugs. There will be basic questions pertaining to the difficulty he is facing which will make us able to ascertain the severity of the reaction. The card will be in a language which is understood by the patient. The card will also direct him towards the health worker and report the same to him. The health worker will redirect him to his DOTS centre where he will be able to consult the doctor. The card will be handed over to the health worker when he receives the next set of drugs and will be given a fresh card.

Another method of collection of ADR is telephonic conversations with the patients every month to ensure that no adverse reactions were missed during the course of the month.The health worker will make monthly calls to the patient to find out if any reactions has occurred and will be collected. Data regarding socio-demographic profile will be extracted from the TB notification register. Data about ADR will be also collected from the TB treatment card.  The demographic data, treatment details and call record details will be entered in the proforma.

 The adverse drug reaction data collected will be filled in the Suspected Adverse Drug Reaction Reporting form provided by the Pharmacovigilance programme of India. The information of patients will be summarized based on demographic characteristics like age, gender, diagnosis, details on adverse drug reactions like onset, pattern, action taken and outcome. Details of suspected drugs causing ADR, with respect to dose, route, duration of therapy, manufacture details and dose modification will be documented. Information will be uploaded in net-based software “Vigiflow†for reporting to the National Coordinating Centre (NCC). The adverse drug reactions will be classified on the basis of Edward and Aronson classification system. Causalityof the adverse drug reaction will be assessed by World Health Organization- Uppsala Monitoring Centre (WHO-UMC) assessment scale which classifies suspected ADRs as certain, probable, possible, unlikely, conditional/unclassified, and unassessable/unclassifiable. Severity of ADR will be assessed by Modified Hartwig and Seigel scale into as mild, moderate or severe. Evaluation of chances of preventability of ADRs was done by using Modified Schumock and Thornton criteria which classifies ADRs as definitely preventable, probably preventable and not preventable

• The study can create an awareness among patients that there is need for reporting, treating and monitoring ADRs.
• This study can benefit in developing strategies to ameliorate ADRs
• Will help us to improve the quality of patient care and to control TB safely.

It can be concluded that adverse events are going to be part and in parallel to the therapeutic effects. It is just a question of balancing risk and benefits of therapy