Abacavir, efavirenz, didanosine, with or without hydroxyurea, in HIV-infected adults failing initial nucleoside/protease inhibitor-containing regimens

Drug-Induced Acute Pancreatitis: An Evidence-Based Classification (Revised)

INTRODUCTION

Drug induced acute pancreatitis is a difficult diagnosis for clinicians. We previously published an "Evidence-Based Classification System" on Drug-Induced Acute Pancreatitis widely used by clinicians to assist in the identification of drugs. Unfortunately, this prior analysis based only on published case reports has been misunderstood. The prior review did not include studies with higher evidentiary value, such as randomized trials, case-control studies, and/or pharmacoepidemiologic studies. The use of the prior classification system has led to many patients being inappropriately labeled as having drug-induced acute pancreatitis. We now propose a "Revised" Evidence- Based Classification System for the purpose of determining which drugs cause acute pancreatitis based on the Grading of Recommendations, Development, and Evaluation criteria.

METHODS

A search of the English Language literature was performed to identify all case reports with medication and/or drug induced acute pancreatitis. We divided the drugs implicated as causing acute pancreatitis into four groups based on the quality of evidence as defined by GRADE quality parameters.

RESULTS

Although 141 drugs were identified in the literature as causing acute pancreatitis, only 106 drugs published in the literature as causing acute pancreatitis were high quality case reports. Only 3 drugs had evidence as causing acute pancreatitis from randomized controlled clinical trials, including 6-mercaptopurine and azathioprine.

DISCUSSION

The vast majority of drugs implicated as causing acute pancreatitis in the literature have low or very low quality of evidence supporting those claims.

Efeitos colaterais cutâneos após uso prolongado de hidroxiuréia na Policitemia Vera

A hidroxiureia é um derivado hidroxilado da ureia utilizado em diversas desordens hematológicas. Inúmeras alterações cutâneas, porém raras, são relatadas após seu uso prolongado. A patogênese das mesmas não está bem esclarecida, porém, sugere-se que a droga tenha uma ação tóxica direta sobre a pele. Descrevemos um homem de 75 anos, branco, com diagnóstico de Policitemia Vera que, ao longo de 11 anos de tratamento com hidroxiureia, evoluiu com várias lesões cutâneas: hiperpigmentação da pele, lesões atróficas em antebraços, melanoníquia longitudinal das 20 unhas, úlcera em antebraço direito, xerose cutânea, ictiose em pernas e carcinoma espinocelular no pavilhão auricular direito. Até o momento, os relatos na literatura descrevem pouca diversidade de lesões nos pacientes acometidos

Methodological issues in the use of composite endpoints in clinical trials: examples from the HIV field

BACKGROUND

In many fields, the choice of a primary endpoint for a trial is not always the ultimate clinical endpoint of interest, but rather some surrogate endpoint believed to be relevant for predicting the effect of the intervention on the clinical endpoint. The classic example of such a field is clinical HIV treatment research, where a variety of primary endpoints are used to evaluate the efficacy of new antiretroviral drugs or new combinations of existing drugs. The choice of endpoint reflects either the goal of therapy as recommended by treatment guidelines (e.g. rapid virological suppression) or the licensing requirements of official drug approval organizations (e.g. time to loss of virological response [TLOVR]).

PURPOSE

To review the diversity of endpoints used in recent clinical trials in HIV infection and highlight the methodological issues.

METHODS

We identified articles relating to antiretroviral therapy by searching PubMed and through hand searches of relevant conference abstracts. We restricted the search to randomized controlled trials conducted in HIV-infected adults published/presented from January 2005 until March 2008.

RESULTS

We identified 28 trials in antiretroviral-naive patients (i.e. patients who were starting antiretroviral therapy for the first time at the time of randomization) and 23 trials in antiretroviral-experienced patients. Most trials were performed for purposes of drug licensing, but others were focused on strategies of using approved drugs. Most trials (40 of 51) used a composite primary endpoint (TLOVR in 13). Of note, 22 of these 40 studies reported that they had used a purely virological efficacy endpoint, but the primary endpoint was actually a composite one due to the way in which missing data and treatment switches were considered as failures.

LIMITATIONS

Examples are restricted to HIV clinical trials.

CONCLUSIONS

Whilst most current HIV clinical trials use composite primary endpoints, there are substantial differences in the components that make up these endpoints. In HIV and other fields where precise definitions are variable, guidelines for standardization of definition and reporting would greatly improve the ability to compare trial results.

Systematic review: Hydroxyurea for the treatment of adults with sickle cell disease

BACKGROUND

Hydroxyurea is the only approved drug for treatment of sickle cell disease.

OBJECTIVE

To synthesize the published literature on the efficacy, effectiveness, and toxicity of hydroxyurea when used in adults with sickle cell disease.

DATA SOURCES

MEDLINE, EMBASE, TOXLine, and CINAHL were searched through 30 June 2007.

STUDY SELECTION

Randomized trials, observational studies, and case reports evaluating efficacy and toxicity of hydroxyurea in adults with sickle cell disease, and toxicity studies of hydroxyurea in other conditions that were published in English.

DATA EXTRACTION

Paired reviewers abstracted data on study design, patient characteristics, and outcomes sequentially and did quality assessments independently.

DATA SYNTHESIS

In the single randomized trial, the hemoglobin level was higher in hydroxyurea recipients than placebo recipients after 2 years (difference, 6 g/L), as was fetal hemoglobin (absolute difference, 3.2%). The median number of painful crises was 44% lower than in the placebo group. The 12 observational studies that enrolled adults reported a relative increase in fetal hemoglobin of 4% to 20% and a relative reduction in crisis rates by 68% to 84%. Hospital admissions declined by 18% to 32%. The evidence suggests that hydroxyurea may impair spermatogenesis. Limited evidence indicates that hydroxyurea treatment in adults with sickle cell disease is not associated with leukemia. Likewise, limited evidence suggests that hydroxyurea and leg ulcers are not associated in patients with sickle cell disease, and evidence is insufficient to estimate the risk for skin neoplasms, although these outcomes can be attributed to hydroxyurea in other conditions.

LIMITATION

Only English-language articles were included, and some studies were of lower quality.

CONCLUSION

Hydroxyurea has demonstrated efficacy in adults with sickle cell disease. The paucity of long-term studies limits conclusions about toxicity.

Systematic review: Hydroxyurea for the treatment of adults with sickle cell disease

BACKGROUND

Hydroxyurea is the only approved drug for treatment of sickle cell disease.

OBJECTIVE

To synthesize the published literature on the efficacy, effectiveness, and toxicity of hydroxyurea when used in adults with sickle cell disease.

DATA SOURCES

MEDLINE, EMBASE, TOXLine, and CINAHL were searched through 30 June 2007.

STUDY SELECTION

Randomized trials, observational studies, and case reports evaluating efficacy and toxicity of hydroxyurea in adults with sickle cell disease, and toxicity studies of hydroxyurea in other conditions that were published in English.

DATA EXTRACTION

Paired reviewers abstracted data on study design, patient characteristics, and outcomes sequentially and did quality assessments independently.

DATA SYNTHESIS

In the single randomized trial, the hemoglobin level was higher in hydroxyurea recipients than placebo recipients after 2 years (difference, 6 g/L), as was fetal hemoglobin (absolute difference, 3.2%). The median number of painful crises was 44% lower than in the placebo group. The 12 observational studies that enrolled adults reported a relative increase in fetal hemoglobin of 4% to 20% and a relative reduction in crisis rates by 68% to 84%. Hospital admissions declined by 18% to 32%. The evidence suggests that hydroxyurea may impair spermatogenesis. Limited evidence indicates that hydroxyurea treatment in adults with sickle cell disease is not associated with leukemia. Likewise, limited evidence suggests that hydroxyurea and leg ulcers are not associated in patients with sickle cell disease, and evidence is insufficient to estimate the risk for skin neoplasms, although these outcomes can be attributed to hydroxyurea in other conditions.

LIMITATION

Only English-language articles were included, and some studies were of lower quality.

CONCLUSION

Hydroxyurea has demonstrated efficacy in adults with sickle cell disease. The paucity of long-term studies limits conclusions about toxicity.

Pharmacokinetic evaluation of the effects of ribavirin on zidovudine triphosphate formation: ACTG 5092s Study Team

OBJECTIVES

Ribavirin (RBV) is used for the treatment of hepatitis C virus (HCV) infection in subjects with HIV-1 infection who may require antiretroviral treatment (ART) with nucleoside reverse transcriptase inhibitors including zidovudine (ZDV). We sought to investigate the potential antagonism between RBV and ZDV by evaluating the impact of RBV on the formation of intracellular ZDV triphosphate (TP) in HIV-infected patients receiving ZDV who were treated for HCV infection.

METHODS

Serial plasma and intracellular ZDV TP pharmacokinetics (PK) were determined in 14 subjects at entry (within 2 weeks prior to RBV administration) and at 8 weeks following initiation of RBV. Intracellular ZDV TP in peripheral blood mononuclear cells (PBMC) was quantified by a validated cartridge/liquid chromatography/tandem mass spectrometry method. PK exposure was estimated from the steady-state area under the concentration vs time curve (AUC(0-12 h)) in plasma and PBMC.

RESULTS

Ribavirin did not have a statistically significant impact on ZDV TP AUC(0-12 h), plasma ZDV AUC(0-12 h) or the ratio of ZDV TP AUC(0-12 h) to plasma ZDV AUC(0-12 h), although there was a trend towards an increase post-RBV ratio compared with pre-RBV. There was extensive variability in the ZDV TP AUC(0-12 h).

CONCLUSIONS

Ribavirin did not inhibit formation of ZDV TP in PBMC in 14 patients receiving ZDV as part of ART and RBV-based HCV therapy for 8 weeks. These results are consistent with those of a previously published limited study in seven subjects. These PK findings should be weighed carefully against emerging clinical reports of significant anaemia associated with combination ZDV and high-dose RBV therapy.

Antiretroviral therapy: a primer for dermatologists

Combination antiretroviral therapy (ART) has transformed the care of individuals who have HIV infection. Effective ART has resulted in dramatic reductions in mortality, hospitalization rates, and the development of AIDS-defining illnesses. This article discusses the variety of agents that can comprise an effective ART regimen, focusing on the basic principles of ART, the indications for initiating ART in treatment-naive individuals who have established HIV infection, and the challenges associated with the use of antiretroviral medications.