ADVERSE EVENTS TO FIRST LINE ANTI-TUBERCULOSIS DRUGS IN PATIENTS CO-INFECTED WITH HIV AND TUBERCULOSIS


O.S. Michael1, O.M. Sogaolu2, F.A. Fehintola1, O.M. Ige2 and C.O. Falade1

  1. Department of Pharmacology and Therapeutics, College of Medicine, University of Ibadan, Nigeria.
  2. Chest Unit, Department of Medicine, College of Medicine, University of Ibadan, Nigeria.

Abstract

Background: The combination and use of multiple drugs in the treatment of tuberculosis (TB) predispose to adverse drug events and reactions. This study evaluated the incidence, frequency, and severity of adverse events to first line anti-tuberculosis (anti-TB) drugs in patients with TB and co-infections with
Human Immunodeficiency Virus (HIV).

Objectives: The objective of this study was to determine the effects of HIV status on the risk of developing adverse events to first line anti-TB therapy.

Method: The study was carried out between 2006 and 2007 when TB therapy was administered without concomitant anti-retroviral therapy. Patients with TB presenting at the chest clinic of a tertiary hospital were sequentially enrolled. Those with TB alone were allocated to the first group while those with TB-HIV infection were allocated to a second group. A checklist of adverse events to the drugs was used to screen for adverse drug events and reactions during the period of anti-TB therapy. Adverse drug events were graded as serious and others (mild-moderate).

Results: One hundred and three patients completed the study. Thirty one (30.1%) of the patients had TB-HIV co-infection. Majority (70.4%) of the events were detected during the first week of therapy, 92% of these events were mild moderate. Eight (25.5%) of those with TB-HIV co-infection had serious adverse events. All the serious events occurred in the TB-HIV group. Independent factors for occurrence of ADEs include HIV status, increasing age, and female gender.

Conclusions: The rate of adverse drug events among patients on first line anti-tuberculosis treatment was higher in HIV co-infected patients.

Keywords: Adverse drug events; Tuberculosis; Anti-TB therapy; HIV co-infection, Nigeria

Correspondence:

Dr. O.S. Michael
Dept. of Pharmacology and Therap.,
College of Medicine,
University of Ibadan,
Nigeria
E-mail: micobaro@yahoo.com
Telephone: +2348056642410

Introduction

Tuberculosis (TB) is the leading cause of morbidity and mortality among people living with Human Immunodeficiency Virus (HIV), particularly in developing countries1. The disease is a major public health problem in Nigeria, with the country ranking 5th among the 22 high TB burden countries which collectively bear 80% of the global burden of TB 2. The number of TB cases notified in the country increased from 31,264 in 2002 to 90,307 in 2008 and 20 – 30% of these patients had HIV co-infection 2. The disease has been shown to progress more rapidly and management poses more challenges in those coinfected with HIV 3. Thus, there is the need for studies evaluating interactions between the two diseases to guide development of effective treatment policies.

Effective chemotherapy is the mainstay of treatment of tuberculosis and this is largely based on patients’ willingness to comply with prescribed regimen. Adverse Drug Events (ADEs) and Adverse Drug Reactions (ADRs) are significant factors in the compliance of patients to medications. These reactions are more common when drugs are taken frequently, in combination, and over prolonged periods. Despite the high level of under-reporting of actual and suspected ADRs 4, it has been shown that adverse drug reactions can be significant factors in the treatment of chronic conditions like tuberculosis 5,6. Studies conducted in developing countries have shown that HIV status is a risk factor for the development of anti-TB drug reactions 7.

Many published reports on anti-TB ADEs are from retrospective studies or are components of studies whose primary objectives are not the detection of ADEs. These studies are likely to have reported lower incidences of ADEs; it has been recommended that prospective observational study designs ought to be used in evaluating adverse drugs events and reactions 8. In addition, studies evaluating the effects of HIV status on ADEs to anti-TB treatment are few, especially in sub-Saharan Africa. This study evaluated the effects of HIV status on ADEs to first line anti-TB treatment using a prospective observational design.