Durability of stavudine, lamivudine and nevirapine among advanced HIV-1 infected patients with/without prior co-administration of rifampicin: a 144-week prospective study

The Global Health Impact Index: Promoting Global Health

Millions of people cannot access essential medicines they need for deadly diseases like malaria, tuberculosis (TB) and HIV/AIDS. There is good information on the need for drugs for these diseases but until now, no global estimate of the impact drugs are having on this burden. This paper presents a model measuring companies' key malaria, TB and HIV/AIDS drugs' consequences for global health (global-health-impact.org). It aggregates drugs' impacts in several ways-by disease, country and originator-company. The methodology can be extended across diseases as well as drugs to provide a more extensive picture of the impact companies' drugs are having on the global burden of disease. The study suggests that key malaria, TB and HIV/AIDS drugs are, together, ameliorating about 37% of the global burden of these diseases and Sanofi, Novartis, and Pfizer's drugs are having the largest effect on this burden. Moreover, drug impacts vary widely across countries. This index provides important information for policy makers, pharmaceutical companies, countries, and other stake-holders that can help increase access to essential medicines.

The effect of tuberculosis treatment on virologic and CD4+ cell count response to combination antiretroviral therapy: a systematic review

OBJECTIVE

To determine the impact of tuberculosis (TB) treatment at the time of combination antiretroviral therapy (cART) initiation on virologic and CD4 cell count response to cART.

METHODS

Systematic review and meta-analysis of studies reporting HIV RNA and CD4 cell count response, stratified by TB treatment status at cART initiation. Stratified random-effects and meta-regression analyses were used when possible.

RESULTS

Twenty-five eligible cohort studies reported data on 49 578 (range 42-15 646) adults, of whom 8826 (18%) were receiving TB treatment at cART initiation. Seventeen studies reported virologic response; 21 reported CD4 cell count response. The summarized random-effects relative risk (RRRE) of virologic suppression in those receiving vs. not receiving TB treatment at different time points following cART initiation was 1.06 (0.86-1.29) at 1-4 months, 0.91 (0.83-1.00) at 6 months, 0.99 (0.94-1.05) at 11-12 months, and 0.99 (0.77-1.28) at 18-48 months. The overall RRRE at 1-48 months was 0.97 (95% confidence interval 0.92-1.03). Available data regarding the effect of TB treatment on virologic failure were heterogeneous and inconclusive (13 estimates). Differences in median CD4 cell count gain between those receiving vs. not receiving TB treatment ranged from -10 to 60 cells/μl (median 27) by 6 months (seven estimates) and -10 to 29 (median 6) by 11-12 months (five estimates), although the heterogeneity of the response measures did not support meta-analysis.

CONCLUSION

Patients receiving TB treatment at cART initiation experience similar virologic suppression and CD4 cell count reconstitution as those not receiving TB treatment, reinforcing the need to start cART during TB treatment and allowing more confidence in clinical decision-making.

Rifampicin-warfarin interaction leading to macroscopic hematuria: a case report and review of the literature

Background

Rifampicin remains one of the first-line drugs used in tuberculosis therapy. This drug´s potential to induce the hepatic cytochrome P450 oxidative enzyme system increases the risk of drug-drug interactions. Thus, although the presence of comorbidities typically necessitates the use of multiple drugs, the co-administration of rifampicin and warfarin may lead to adverse drug events. We report a bleeding episode after termination of the co-administration of rifampicin and warfarin and detail the challenges related to international normalized ratio (INR) monitoring.

Case presentation

A 59-year-old Brazilian woman chronically treated with warfarin for atrial fibrillation (therapeutic INR range: 2.0-3.0) was referred to a multidisciplinary anticoagulation clinic at a university hospital. She showed anticoagulation resistance at the beginning of rifampicin therapy, as demonstrated by repeated subtherapeutic INR values. Three months of sequential increases in the warfarin dosage were necessary to reach a therapeutic INR, and frequent visits to the anticoagulation clinic were needed to educate the patient about her pharmacotherapy and to perform the warfarin dosage adjustments. The warfarin dosage also had to be doubled at the beginning of rifampicin therapy. However, four weeks after rifampicin discontinuation, an excessively high INR was observed (7.22), with three-day macroscopic hematuria and the need for an immediate reduction in the warfarin dosage. A therapeutic and stable INR was eventually attained at 50% of the warfarin dosage used by the patient during tuberculosis therapy.

Conclusions

The present case exemplifies the influence of rifampicin therapy on warfarin dosage requirements and the increased risk of bleeding after rifampicin discontinuation. Additionally, this case highlights the need for warfarin weekly monitoring after stopping rifampicin until the maintenance dose of warfarin has decreased to the amount administered before rifampicin use. In particular, patients with cardiovascular diseases and active tuberculosis represent a group with a substantial risk of drug-drug interactions. Learning how to predict and monitor drug-drug interactions may help reduce the incidence of clinically significant adverse drug events.

Clinical Characteristics of HIV-Infected Patients Who Survive after the Diagnosis of HIV Infection for More Than 10 Years in a Resource-Limited Setting

A retrospective cohort study was conducted and 129 patients with a diagnosis of HIV infection for more than 10 years were identified. Half the patients were men and mean (standard deviation, SD) age at HIV diagnosis was 33.2 (9.2) years. One third had a diagnosis of AIDS at cohort entry with median (interquartile range, IQR) CD4 counts of 259 (112-430) cells/mm3. All received antiretroviral therapy with median (IQR) current CD4 counts of 502 (363-607) cells/mm3 and 95% had HIV RNA <50 copies/mL. For adverse events, 28% experienced drug resistance, 27% experienced hospitalization, 59% had dyslipidemia, 35% had creatinine >1.0 mg/dL, and 5% had glucose >126 mg/dL. In conclusion, immunological and virological responses can be achieved among patients with a diagnosis of HIV infection for more than 10 years even in a resource-limited setting. Adverse events are common. Preparation for monitoring and management of these adverse events is a crucial part of successful long-term HIV care.