Management of protease inhibitor-associated hyperlipidemia

Clinical Outcomes After Acute Coronary Syndromes or Revascularization Among People Living With HIV: A Systematic Review and Meta-Analysis

Importance

Clinical outcomes after acute coronary syndromes (ACS) or percutaneous coronary interventions (PCIs) in people living with HIV have not been characterized in sufficient detail, and extant data have not been synthesized adequately.

Objective

To better characterize clinical outcomes and postdischarge treatment of patients living with HIV after ACS or PCIs compared with patients in an HIV-negative control group.

Data Sources

Ovid MEDLINE, Embase, and Web of Science were searched for all available longitudinal studies of patients living with HIV after ACS or PCIs from inception until August 2023.

Study Selection

Included studies met the following criteria: patients living with HIV and HIV-negative comparator group included, patients presenting with ACS or undergoing PCI included, and longitudinal follow-up data collected after the initial event.

Data Extraction and Synthesis

Data extraction was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. Clinical outcome data were pooled using a random-effects model meta-analysis.

Main Outcome and Measures

The following clinical outcomes were studied: all-cause mortality, major adverse cardiovascular events, cardiovascular death, recurrent ACS, stroke, new heart failure, total lesion revascularization, and total vessel revascularization. The maximally adjusted relative risk (RR) of clinical outcomes on follow-up comparing patients living with HIV with patients in control groups was taken as the main outcome measure.

Results

A total of 15 studies including 9499 patients living with HIV (pooled proportion [range], 76.4% [64.3%-100%] male; pooled mean [range] age, 56.2 [47.0-63.0] years) and 1 531 117 patients without HIV in a control group (pooled proportion [range], 61.7% [59.7%-100%] male; pooled mean [range] age, 67.7 [42.0-69.4] years) were included; both populations were predominantly male, but patients living with HIV were younger by approximately 11 years. Patients living with HIV were also significantly more likely to be current smokers (pooled proportion [range], 59.1% [24.0%-75.0%] smokers vs 42.8% [26.0%-64.1%] smokers) and engage in illicit drug use (pooled proportion [range], 31.2% [2.0%-33.7%] drug use vs 6.8% [0%-11.5%] drug use) and had higher triglyceride (pooled mean [range], 233 [167-268] vs 171 [148-220] mg/dL) and lower high-density lipoprotein-cholesterol (pooled mean [range], 40 [26-43] vs 46 [29-46] mg/dL) levels. Populations with and without HIV were followed up for a pooled mean (range) of 16.2 (3.0-60.8) months and 11.9 (3.0-60.8) months, respectively. On postdischarge follow-up, patients living with HIV had lower prevalence of statin (pooled proportion [range], 53.3% [45.8%-96.1%] vs 59.9% [58.4%-99.0%]) and β-blocker (pooled proportion [range], 54.0% [51.3%-90.0%] vs 60.6% [59.6%-93.6%]) prescriptions compared with those in the control group, but these differences were not statistically significant. There was a significantly increased risk among patients living with HIV vs those without HIV for all-cause mortality (RR, 1.64; 95% CI, 1.32-2.04), major adverse cardiovascular events (RR, 1.11; 95% CI, 1.01-1.22), recurrent ACS (RR, 1.83; 95% CI, 1.12-2.97), and admissions for new heart failure (RR, 3.39; 95% CI, 1.73-6.62).

Conclusions and Relevance

These findings suggest the need for attention toward secondary prevention strategies to address poor outcomes of cardiovascular disease among patients living with HIV.

A lipid index for risk of hyperlipidemia caused by anti-retroviral drugs

HIV-associated lipodystrophy has been reported in people taking anti-retroviral therapy (ART). Lipodystrophy can cause cardiovascular diseases, affecting the quality of life of HIV-infected individuals. In this study, we propose a pharmacological lipid index to estimate the risk of hyperlipidemia caused by anti-retroviral drugs. Lipid droplets were stained in cells treated with anti-retroviral drugs and cyclosporin A. Signal intensities of lipid droplets were plotted against the drug concentrations to obtain an isodose of 10 μM of cyclosporin A, which we call the Pharmacological Lipid Index (PLI). The PLI was then normalized by EC50. PLI/EC50 values were low in early proteinase inhibitors and the nucleoside reverse transcriptase inhibitor, d4T, indicating high risk of hyperlipidemia, which is consistent with previous findings of hyperlipidemia. In contrast, there are few reports of hyperlipidemia for drugs with high PLI/EC50 scores. Data suggests that PLI/EC50 is a useful index for estimating the risk of hyperlipidemia.

COVID-19: An Update on the Epidemiological, Clinical, Preventive, and Therapeutic Management of 2019 Novel Coronavirus Disease

The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2) remains a serious issue for global health, given widespread infectivity and a high contagion rate. A tremendous amount of data has been generated since it was first identified in December 2019. It is vital to keep up with these data from across the world at a time of uncertainty and continuously evolving guidelines and clinical practice. This review provides an update on recent developments concerning epidemiology, clinical presentation, treatment options, and scientific advancements to combat the COVID-19 pandemic.

Managing hyperlipidaemia in patients with COVID-19 and during its pandemic: An expert panel position statement from HEART UK

The emergence of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which causes Coronavirus Disease 2019 (COVID-19) has resulted in a pandemic. SARS-CoV-2 is highly contagious and its severity highly variable. The fatality rate is unpredictable but is amplified by several factors including advancing age, atherosclerotic cardiovascular disease, diabetes mellitus, hypertension and obesity. A large proportion of patients with these conditions are treated with lipid lowering medication and questions regarding the safety of continuing lipid-lowering medication in patients infected with COVID-19 have arisen. Some have suggested they may exacerbate their condition. It is important to consider known interactions with lipid-lowering agents and with specific therapies for COVID-19. This statement aims to collate current evidence surrounding the safety of lipid-lowering medications in patients who have COVID-19. We offer a consensus view based on current knowledge and we rated the strength and level of evidence for these recommendations. Pubmed, Google scholar and Web of Science were searched extensively for articles using search terms: SARS-CoV-2, COVID-19, coronavirus, Lipids, Statin, Fibrates, Ezetimibe, PCSK9 monoclonal antibodies, nicotinic acid, bile acid sequestrants, nutraceuticals, red yeast rice, Omega-3-Fatty acids, Lomitapide, hypercholesterolaemia, dyslipidaemia and Volanesorsen. There is no evidence currently that lipid lowering therapy is unsafe in patients with COVID-19 infection. Lipid-lowering therapy should not be interrupted because of the pandemic or in patients at increased risk of COVID-19 infection. In patients with confirmed COVID-19, care should be taken to avoid drug interactions, between lipid-lowering medications and drugs that may be used to treat COVID-19, especially in patients with abnormalities in liver function tests.

The Impact of Pre-existing Comorbidities and Therapeutic Interventions on COVID-19

Evidence from the global outbreak of SARS-CoV-2 has clearly demonstrated that individuals with pre-existing comorbidities are at a much greater risk of dying from COVID-19. This is of great concern for individuals living with these conditions, and a major challenge for global healthcare systems and biomedical research. Not all comorbidities confer the same risk, however, many affect the function of the immune system, which in turn directly impacts the response to COVID-19. Furthermore, the myriad of drugs prescribed for these comorbidities can also influence the progression of COVID-19 and limit additional treatment options available for COVID-19. Here, we review immune dysfunction in response to SARS-CoV-2 infection and the impact of pre-existing comorbidities on the development of COVID-19. We explore how underlying disease etiologies and common therapies used to treat these conditions exacerbate COVID-19 progression. Moreover, we discuss the long-term challenges associated with the use of both novel and repurposed therapies for the treatment of COVID-19 in patients with pre-existing comorbidities.

Hemostasis in elderly patients with human immunodeficiency virus (HIV) infection-Cross-sectional study

Introduction: Aging and chronic HIV infection are clinical conditions that share the states of inflammation and hypercoagulability. The life expectancy of the world population has increased in the last decades, bringing as complications the occurrence of diseases that undergoing metabolic, bone, cardiological, vascular and neurological alterations. HIV-infected patients experience these changes early and are living longer due to the success of antiretroviral therapy. The objectives of this study was to evaluate some changes in the plasma hemostatic profile of 115 HIV-reactive elderly individuals over 60 years old in the chronic phase of infection, and compare with 88 healthy uninfected elderly individuals. Plasma determinations of D-dimers, Fibrinogen, von Willebrand Factor, Antithrombin, Prothrombin Time, Activated Partial Thromboplastin Time, and platelet count were performed. In the HIV-reactive group, these variables were analyzed according to viral load, protease inhibitor use and CD4⁺ T lymphocyte values. After adjusted values for age and sex, the results showed higher levels of Antithrombin (103%; 88%, p = 0.0001) and Prothrombin Time activities (92.4%; 88.2%, p = 0.019) in the HIV group compared to the control group. We observed higher values of Fibrinogen in protease inhibitor users in both the male (p = 0.043) and female (p = 0.004) groups, and in the female HIV group with detected viral load (p = 0.015). The male HIV group with a CD4⁺ count> 400 cells / mm³ presented higher von Willebrand Factor values (p = 0.036). D-Dimers had higher values in the older age groups (p = 0.003; p = 0.042, respectively). Conclusion: Our results suggest that the elderly with chronic HIV infection with few comorbidities had a better hemostatic profile than negative control group, reflecting the success of treatment. Protease inhibitor use and age punctually altered this profile.

Fenofibrate/simvastatin fixed-dose combination in the treatment of mixed dyslipidemia: safety, efficacy, and place in therapy

Lipids disorder is the principal cause of atherosclerosis and may present with several forms, according to blood lipoprotein prevalence. One of the most common forms is combined dyslipidemia, characterized by high levels of triglycerides and low level of high-density lipoprotein. Single lipid-lowering drugs may have very selective effect on lipoproteins; hence, the need to use multiple therapy against dyslipidemia. However, the risk of toxicity is a concerning issue. In this review, the effect and safety of an approved combination therapy with simvastatin plus fenofibrate are described, with an analysis of pros and cons resulting from randomized multicenter trials, meta-analyses, animal models, and case reports as well.

Drug-Drug Interactions and HIV Therapy: What Should Pharmacists Know?

Drug-interaction issues continue to present a major dilemma for the clinician caring for complex patients such as those infected with HIV. The inherent possibility of a drug interaction is magnified by the multitude of drugs being administered in highly-active antiretroviral therapy (HAART). In addition, other classes of medications are used to alleviate side effects, reduce toxicities associated with HAART, or treat concomitant diseases. The modification of one drug by another substance or drug-drug interaction is the main focus of this article. Drug-drug interactions may result in toxicity, treatment failure, or loss of effectiveness and can significantly affect a patient’s clinical outcome. An understanding of the fundamental mechanisms of HIV drug-drug interactions may allow for the early detection or avoidance of troublesome regimens and prudent management if they develop. Although HIV drug interactions are usually thought of as detrimental, resulting in a loss of therapeutic effect or toxicity, some drug interactions such as ritonavir boosted protease inhibitor–based antiretroviral treatments are beneficial and are commonly used in clinical practice. Therefore, pharmacists need to understand drug interaction mechanisms, remember key drug interactions, and vigilantly monitor patients for potential complications.

Drug therapies for HIV-related metabolic disorders

INTRODUCTION

Human immunodeficiency virus (HIV) has become a chronic disease often associated with dyslipidaemia and insulin resistance. Combination antiretroviral therapy (cART) may contribute to metabolic disturbances, eventually leading to increased cardiovascular disease (CVR) in this population. Escalating interventions to decrease CVR include promoting a healthy lifestyle, such as quitting smoking, diet and regular exercise. If they do not achieve the goals, a change of cART should be considered, followed by or used concomitantly with the use of chemical therapies.

AREAS COVERED

The aim of this article is to review the available drug therapies for the treatment of metabolic disorders in HIV-infected patients and to examine their safety and effectiveness in this population. A review of the literature was conducted, highlighting the most relevant articles.

EXPERT OPINION

Switching strategies can be useful but its expected benefit is not high. Therefore, chemical intervention is often needed. Statins have been proven to reduce CVR in the general population and in HIV-infected patients. Simvastatin is contraindicated in patients treated with boosted PI due to interactions; atorvastatin is safe at submaximal dose and needs close monitoring, while pravastatin lacks lipid-lowering potency, and rosuvastatin and pitavastatin are safe. Ezetimibe and fibrates are also safe and effective in HIV-infected patients and can be used in combination with statins. The management of glucose homeostatic disorders in HIV-infected patients follows the same guidelines as in the general population. However, there are specific considerations with respect to the interactions of particular medications with cART. When drug therapy is needed, metformin is the first-line drug. Decisions regarding second- and third-line drugs should be carefully individualized.

Lack of an Effect of Ritonavir Alone and Lopinavir-Ritonavir on the Pharmacokinetics of Fenofibric Acid in Healthy Volunteers

STUDY OBJECTIVE

Because we previously observed a significant 41% reduction in gemfibrozil exposure after 2 weeks of lopinavir-ritonavir administration, we sought to determine the influence of lopinavir-ritonavir and ritonavir alone on the pharmacokinetics of fenofibric acid, an alternative to gemfibrozil for the treatment of elevated triglyceride levels.

DESIGN

Open-label, single-sequence pharmacokinetic study.

SETTING

Clinical Research Center at the National Institutes of Health.

SUBJECTS

Thirteen healthy adult volunteers.

INTERVENTION

Subjects received a single oral dose of fenofibrate 145 mg during three study phases: before ritonavir administration, after 2 weeks of administration of ritonavir 100 mg twice/day, and after 2 weeks of administration of lopinavir 400 mg-ritonavir 100 mg twice/day.

MEASUREMENTS AND MAIN RESULTS

Serial blood samples were collected over 120 hours for determination of fenofibric acid concentrations. Fenofibric acid pharmacokinetic parameter values were compared before and after concomitant ritonavir or lopinavir-ritonavir administration. The geometric mean ratios (90% confidence intervals) for fenofibric acid area under the plasma concentration-time curve were 0.89 (0.77-1.01) after 14 days of ritonavir alone compared with baseline (p>0.05) and 0.87 (0.69-1.05) after 14 days of lopinavir-ritonavir compared with baseline (p>0.05). Study drugs were generally well tolerated; all adverse events were mild or moderate, transient, and resolved without intervention.

CONCLUSION

In contrast to a significant interaction between gemfibrozil and lopinavir-ritonavir, neither lopinavir-ritonavir nor ritonavir alone altered the pharmacokinetics of fenofibric acid in healthy volunteers. These data suggest that fenofibrate remains an important option in human immunodeficiency virus-infected patients receiving common ritonavir-boosted therapy.

Marketed nonsteroidal anti-inflammatory agents, antihypertensives, and human immunodeficiency virus protease inhibitors: as-yet-unused weapons of the oncologists' arsenal

Experimental data indicate that several pharmacological agents that have long been used for the management of various diseases unrelated to cancer exhibit profound in vitro and in vivo anticancer activity. This is of major clinical importance, since it would possibly aid in reassessing the therapeutic use of currently used agents for which clinicians already have experience. Further, this would obviate the time-consuming process required for the development and the approval of novel antineoplastic drugs. Herein, both pre-clinical and clinical data concerning the antineoplastic function of distinct commercially available pharmacological agents that are not currently used in the field of oncology, ie, nonsteroidal anti-inflammatory drugs, antihypertensive agents, and anti-human immunodeficiency virus agents inhibiting viral protease, are reviewed. The aim is to provide integrated information regarding not only the molecular basis of the antitumor function of these agents but also the applicability of the reevaluation of their therapeutic range in the clinical setting.

Managing dyslipidemia in HIV/AIDS patients: challenges and solutions

Human immunodeficiency virus (HIV) is a chronic disease associated with dyslipidemia and insulin resistance. In addition, the administration of combination antiretroviral therapy is associated with an increase in the incidence of metabolic risk factors (insulin resistance, lipoatrophy, dyslipidemia, and abnormalities of fat distribution in HIV patients). HIV dyslipidemia is a common problem, and associated with an increase in incidence of cardiovascular disease. Further challenges in the management of HIV dyslipidemia are the presence of diabetes and metabolic syndrome, nonalcoholic fatty liver disease, hypothyroidism, chronic kidney disease, the risk of diabetes associated with statin administration, age and ethnicity, and early menopause in females. Dyslipidemia in patients with HIV is different from the normal population, due to the fact that HIV increases insulin resistance and HIV treatment not only may induce dyslipidemia but also may interact with lipid-lowering medication. The use of all statins (apart from simvastatin and lovastatin) is safe and effective in HIV dyslipidemia, and the addition of ezetimibe, fenofibrate, fish oil, and niacin can be used in statin-unresponsive HIV dyslipidemia. The management of dyslipidemia and cardiovascular disease risks associated with HIV is complex, and a certain number of patients may require management in specialist clinics run by specialist physicians in lipid disorders. Future research is needed to address best strategies in the management of hyperlipidemia with HIV infection.

HIV stroke risk: evidence and implications

An estimated 34 million men, women, and children are infected with human immunodeficiency virus type 1 (HIV-1), the virus that causes acquired immunodeficiency syndrome (AIDS). Current technology cannot eradicate HIV-1, and most patients with HIV-1-infection (HIV+) will require lifelong treatment with combined antiretroviral therapy (cART). Stroke was recognized as a complication of HIV-1 infection since the early days of the epidemic. Potential causes of stroke in HIV-1 include opportunistic infections, tumors, atherosclerosis, diabetes, hypertension, autoimmunity, coagulopathies, cardiovascular disease, and direct HIV-1 infection of the arterial wall. Ischemic stroke has emerged as a particularly significant neurological complication of HIV-1 and its treatment due to the aging of the HIV+ population, chronic HIV-1 infection, inflammation, and prolonged exposure to cART. New prevention and treatment strategies tailored to the needs of the HIV+ population are needed to address this issue.

Practical Perspectives on the Use of Tipranavir in Combination With Other Medications: Lessons Learned From Pharmacokinetic Studies

Drug-drug interactions are a major practical concern for physicians treating human immunodeficiency virus (HIV) because of the many medications that HIV-positive patients must take. Pharmacokinetic drug interactions can occur at different levels (absorption, distribution, metabolism, excretion) and are difficult to predict. Of all the processes that give rise to drug interactions, metabolism by cytochrome P450 (CYP3A) is the most frequent. Moreover, medications prescribed to HIV-positive patients may also be CYP3A inhibitors and inducers: Tipranavir, in the absence of ritonavir, is a CYP3A inducer, and ritonavir is a CYP3A inhibitor. Fortunately, the drug interactions between tipranavir coadministered with ritonavir and other antiretroviral medications or with other medications commonly used in HIV therapy are well characterized. This review summarizes the pharmacokinetic interactions between tipranavir/ritonavir and 11 other antiretroviral medications and between tipranavir/ritonavir and drugs used to treat opportunistic infections such as fungal infections, antiretroviral-treatment-related conditions such as hyperlipidemia, and side effects such as diarrhea.

An Increase in Serum Creatinine after Initiation of Fenofibrate in an HIV-Infected Individual: A Case Report and Review of the Literature

Hypertriglyceridemia is common among patients infected with HIV and often requires treatment with a triglyceride-lowering medication, such as fenofibrate. Studies have shown that fenofibrate has the potential to increase serum creatinine, a phenomenon that seems to occur more in patients with baseline renal dysfunction or who are on medications that can affect renal hemodynamics. HIV-infected individuals are at an increased risk of developing renal problems and may be a target population for fenofibrate-induced increases in serum creatinine. The purpose of this report is to describe a case of an HIV-infected individual who experienced a considerable increase in serum creatinine after initiating fenofibrate, and to highlight this underreported yet important adverse effect. Additionally, we discuss the postulated mechanisms, relevant literature among HIV noninfected individuals, and potential risk factors.

Gemfibrozil concentrations are significantly decreased in the presence of lopinavir-ritonavir

OBJECTIVE

The objective of this study was to determine the influence of a 2-week course of lopinavir-ritonavir on the pharmacokinetics of the triglyceride-lowering agent, gemfibrozil.

METHODS

The study was conducted as an open label, single-sequence pharmacokinetic study in healthy human volunteers. Gemfibrozil pharmacokinetic parameter values were compared using a Student t test after a single 600-mg dose was administered to healthy volunteers before and after 2 weeks of lopinavir-ritonavir (400/100 mg) twice daily.

RESULTS

Fifteen healthy volunteers (eight males) completed the study. All study drugs were generally well tolerated and no subjects withdrew participation. The geometric mean ratio (90% confidence interval) for gemfibrozil area under the plasma concentration-time curve after 14 days of lopinavir-ritonavir compared with baseline was 0.59 (0.52, 0.67) (P < 0.001). All 15 study subjects experienced a reduction in gemfibrozil area under the plasma concentration-time curve after lopinavir-ritonavir (range, -6% to -74%). The geometric mean ratios for gemfibrozil apparent oral clearance and maximum concentration were 1.69 (1.41, 1.97) and 0.67 (0.49, 0.86) after 14 days of lopinavir-ritonavir versus baseline, respectively (P < 0.0001 and 0.01, respectively). Gemfibrozil elimination half-life did not change after lopinavir-ritonavir administration (P = 0.60).

CONCLUSION

Lopinavir-ritonavir significantly reduced the systemic exposure of gemfibrozil by reducing gemfibrozil absorption. Clinicians treating HIV-infected patients with hypertriglyceridemia should be aware of this drug interaction.

Darunavir: a second-generation protease inhibitor

PURPOSE

The pharmacology, pharmacokinetics, drug interactions, clinical efficacy, adverse events, dosage and administration, and place in therapy of darunavir are reviewed.

SUMMARY

Darunavir is the most recent protease inhibitor (PI) to receive approved labeling from the Food and Drug Administration for the treatment of human immunodeficiency virus (HIV). Darunavir is unique among currently available PIs because it maintains antiretroviral activity against a variety of multidrug-resistant HIV strains. Darunavir is well absorbed, and the bioavailability of darunavir increases by 30% when given with food. Darunavir is approximately 95% bound to plasma proteins. Darunavir is metabolized by and inhibits cytochrome P-450 (CYP) isoenzyme 3A4; therefore, darunavir is prone to CYP3A4-mediated drug-drug interactions. Two trials have demonstrated the clinical efficacy of darunavir in HIV-positive patients previously treated with antiretrovirals. One trial demonstrated a 2 log(10) decrease in plasma HIV RNA levels, compared with a decrease of <1 log(10) in the control group. Average increases in CD4+ T-cell counts for darunavir and control groups were 124 and 20 cells/mm(3), respectively. Adverse events reported from preliminary safety data indicate that darunavir has a similar safety profile to other currently available PIs. The recommended adult dosage of darunavir is 600 mg (two tablets) combined with ritonavir 100 mg every 12 hours with food. Darunavir should be used with caution in patients with hepatic dysfunction. No dosage adjustment is necessary for patients with mild or moderate renal dysfunction.

CONCLUSION

Darunavir is a new HIV PI that retains virological activity in the presence of multiple protease mutations. As such, darunavir appears to be a useful component of optimized combination antiretroviral therapy for HIV-infected patients previously treated with antiretrovirals.

HIV protease inhibitors modulate apoptosis signaling in vitro and in vivo

HIV protease inhibitors are an integral part of effective anti-HIV therapy. The drugs block HIV protease, prevent proper packaging of HIV virions, and decrease the HIV viral burden in the peripheral blood of infected individuals. In addition to direct anti-viral effects, the HIV protease inhibitors also modulate apoptosis. A growing body of work demonstrates the anti-apoptotic effects of HIV protease inhibitors on CD4+ and CD8+ T cells during HIV infection. The mechanism of this apoptosis inhibition is supported by several proposed hypotheses for how they alter the fate of the cell, including preventing adenine nucleotide translocator pore function, which consequently prevents loss of mitochondrial transmembrane potential. More recently, the anti-apoptotic effects of the HIV protease inhibitors have been tested in non-HIV, non-immune cell, whereby protease inhibitors prevent apoptosis, and disease in animal models of sepsis, hepatitis, pancreatitis and stroke. Interestingly, when HIV protease inhibitors are used at supra-therapeutic concentrations, they exert pro-apoptotic effects. This has been demonstrated in a number of tumor models. Although it is unclear how HIV protease inhibitors can induce apoptosis at increased concentrations, future research will define the targets of the immunomodulation and reveal the full clinical potential of this intriguing class of drugs.

Atherosclerosis and central adiposity in a pediatric patient with AIDS treated with HAART: autopsy findings

Several types of cardiovascular lesions may develop in pediatric human immunodeficiency virus-positive (HIV+)/acquired immunodeficiency syndrome (AIDS) patients, namely myocarditis, dilated cardiomyopathy, pericardial effusion, pericarditis, left ventricle hypertrophy, fibrocalcific arteriopathy, and aneurysms. Additional lesions may be discovered by histological examination. These include fibrocalcific lesions in medium-sized arteries and small vessels, mainly of the heart and brain, and vasculitis. In the large arteries the vasa vasorum may present chronic inflammatory infiltrates or leukocytoclastic vasculitis, resulting in aneurysms. We are reporting the case of a 14-year-old girl with mother-to-infant HIV transmission with a long history of several central nervous system infections and AIDS dementia, who received treatment with the HAART protocol (including a protease inhibitor) for 3 years. A year after beginning this treatment, cholesterol serum levels were 2.8 g/L and 3.8 g/L. Autopsy findings showed gross and microscopic features of adult-type atherosclerosis involving the whole thoracic aorta, its main branches, and the coronary arteries. Remarkably, the abdominal aorta and all its branches were almost completely devoid of these lesions. At the same time, although the body presented extreme cachexia, there were obvious subepericardial, periadrenal, and peripancreatic fat deposits. The referred findings may have resulted from the well-known metabolic-dyslipemic syndrome induced by the HAART therapy and have not been specifically mentioned previously in the literature in the particular setting observed in the case of this patient.

Micronized fenofibrate: a useful choice for the correction of dyslipidemia in metabolic syndrome and Type 2 diabetes

Cardiovascular disease is the principal cause of illness and disability in patients with diabetes, and is also the most common cause of death worldwide in adults. Fenofibrate, a member of the fibrate class of lipid-modifying drugs, is a potent triglyceride-lowering and high-density lipoprotein cholesterol-raising agent and has a variable effect on low-density lipoprotein cholesterol. Fenofibrate administration also leads to a modified, less atherogenic low-density lipoprotein profile, with a consistent effect toward increased low-density lipoprotein particle size and a reduction in the low-density lipoprotein particle density. Maximal clinical efficacy in fibrates has been demonstrated in subjects with dyslipidemia, particularly in populations with features of the metabolic syndrome and in patients with Type 2 diabetes. Angiographic data from the Diabetes Atherosclerosis Intervention Study (DAIS) support a similar effect of fenofibrate. However, in the recent Fenofibrate Intervention and Event Lowering in Diabetes trial (FIELD; 9795 patients with Type 2 diabetes), the rate of nonfatal macrovascular events, after adjustment for the use of other lipid-lowering agents and significant reductions in microvascular complications, was lower for the fenofibrate treatment group. These results and those from a current large trial, ACtion to COntrol cardiovascular Risk in Diabetes (ACCORD), will provide valuable evidence for the likely future use of this drug in combination with statins for reducing cardiovascular disease risk in the metabolic syndrome and in Type 2 diabetes.

Pharmacokinetic drug interactions with non-nucleoside reverse transcriptase inhibitors

Non-nucleoside reverse transcriptase inhibitors (NNRTIs) are a diverse group of compounds that inhibit HIV Type 1 reverse transcriptase. Although possessing a common mechanism of action, the approved NNRTIs, delavirdine, efavirenz and nevirapine, differ in structural and pharmacokinetic characteristics. Each of the NNRTIs undergoes biotransformation by the cytochrome P450 (CYP) enzyme system, thus making them prone to clinically significant drug interactions when combined with other antiretrovirals. In addition, they interact with other concurrent medications and complementary/alternative medicines, acting as either inducers or inhibitors of drug-metabolising CYP enzymes. These drug interactions become an important consideration in the clinical use of these agents when designing combination regimens, as recommended by current guidelines. This review provides an updated summary of pharmacokinetic interactions with NNRTIs.

Prednisolone Pharmacokinetics in the Presence and Absence of Ritonavir After Oral Prednisone Administration to Healthy Volunteers

Corticosteroid therapy has been associated with bone toxicities (eg, osteonecrosis) and Cushing syndrome in HIV-infected patients; this may be partially attributable to a pharmacokinetic drug interaction between HIV protease inhibitors and corticosteroids. The purpose of this study was to characterize the influence of low-dose ritonavir on prednisolone pharmacokinetics in healthy subjects. Ten HIV-seronegative volunteers were given single oral doses of prednisone, 20 mg, before (baseline) and after receiving ritonavir, 200 mg, twice daily for 4 and 14 days. After each prednisone dose, serial blood samples were collected and prednisolone concentrations were determined; pharmacokinetic parameter values were compared between the groups. Geometric mean ratios (GMRs, 90% confidence interval [CI]) of the prednisolone area under the plasma concentration versus time curve (AUC0-infinity) after 4 and 14 days of ritonavir versus baseline were 1.41 (90% CI: 1.08 to 1.74) and 1.30 (90% CI: 1.09 to 1.49), respectively (P = 0.002 and P = 0.004, respectively). GMRs of prednisolone apparent oral clearance (Cl/F) were 0.71 (09% CI: 0.57 to 0.93) and 0.77 (90% CI: 0.67 to 0.92) after 4 and 14 days of ritonavir versus baseline, respectively (P = 0.0004 and P = 0.0003, respectively). Ritonavir significantly increased the systemic exposure of prednisolone in healthy subjects. Results from this investigation suggest that corticosteroid exposure is likely elevated in HIV-infected patients receiving protease inhibitors.

Les désordres lipidiques des patients atteints d’affections causées par le VIH

Before the availability of protease inhibitors, elevated triglyceride levels were frequently observed in patients with advanced-stage HIV infection. Since the addition of protease inhibitors to combination treatments, metabolic side effects (alterations in distribution of adipose tissue and metabolic disorders combining dyslipidemia, insulin-resistance and glucose intolerance) have been observed in HIV-positive patients receiving these treatments. Reverse transcriptase nucleoside inhibitors also provoke metabolic disorders. Dyslipidemia is defined by an increase in triglyceride levels of varying and sometimes major intensity, either isolated or combined with a more moderate increase in LDL-cholesterol, while HDL-cholesterol levels may decrease or remain unchanged. These metabolic alterations are potentially atherogenic and may explain these patients' increased risk of cardiovascular disorders. Their mechanism is complex and not yet clearly elucidated. The infection, the improvement in patients' general health and immune status, and individual predisposing factors are probably involved. Treatment probably plays a major role, since the different drugs in these two classes show effects of clearly different intensity. In vitro and ex vivo studies suggest that protease inhibitors alter adipocyte differentiation and induce insulin resistance. Reverse transcriptase nucleoside inhibitors modify adipocyte metabolism too, promoting tissue atrophy. Endocrine factors (cortisol and growth hormones) are also likely to have a role in this hypertrophy of adipose, especially visceral, tissue. These metabolic abnormalities result mainly from the effects of the antiretroviral drugs, notably protease inhibitors, on the hepatic lipid metabolism and on tissue sensitivity to insulin. Lipodystrophy contributes to these abnormalities, as does the reduction in cytokine secretion by adipose tissue. Management of these metabolic disorders is based primarily on a change in the drug regimen (administration of the least deleterious combinations), followed by standard dietary measures and, when necessary, lipid-lowering agents.

Antiretroviral Therapy in HIV-Infected Children: The Metabolic Cost of Improved Survival

Although highly active antiretroviral therapy (HAART) has positively altered the morality rates in HIV-infected children, these drugs have the potential to cause significant morbidity. These drugs cause changes in fat distribution, lipid profiles, glucose, homeostasis, and bone turnover. The direct relationship between duration of drug exposure and increased risk of cardiovascular disease is particularly concerning for HIV-infected infants and children, who likely will have longer cumulative exposure to HAART. It is unclear whether the metabolic effects of decades of exposure would be reversible with cessation of therapy. The benefits of HAART in HIV infection are indisputable, but the impetus to find a cure or design more tolerable therapy is clear. Infarction may replace infection as the major cause of morbidity and mortality from HIV.

Changes in lipids over twelve months after initiating protease inhibitor therapy among persons treated for HIV/AIDS

Background

Protease inhibitors are known to alter the lipid profiles in subjects treated for HIV/AIDS. However, the magnitude of this effect on plasma lipoproteins and lipids has not been adequately quantified.

Objective

To estimate the changes in plasma lipoproteins and triglycerides occurring within 12 months of initiating PI-based antiretroviral therapy among HIV/AIDS afflicted subjects.

Methods

We included all antiretroviral naïve HIV-infected persons treated at St-Paul's Hospital, British Columbia, Canada, who initiated therapy with protease inhibitor antiretroviral (ARV) drugs between August 1996 and January 2002 and who had at least one plasma lipid measurement. Longitudinal associations between medication use and plasma lipids were estimated using mixed effects models that accounted for repeated measures on the same subjects and were adjusted for age, sex, time dependent CD4+ T-cell count, and time dependent cumulative use of non-nucleoside reverse transcriptase inhibitors and adherence. The cumulative number of prescriptions filled for PIs was considered time dependent. We estimated the changes in the 12 months following any initiation of a PI based regimen.

Results

A total of 679 eligible subjects were dispensed nucleoside analogues and PI at the initiation of therapy. Over a median 47 months of follow-up (interquartile range (IQR): 29–62), subjects had a median of 3 (IQR: 1–6) blood lipid measurements. Twelve months after treatment initiation of PI use, there was an estimated 20% (95% confidence interval: 17% – 24%) increase in total cholesterol and 22% (12% – 33%) increase in triglycerides.

Conclusions

Twelve months after treatment initiation with PIs, statistically significant increases in total cholesterol and triglycerides levels were observed in HIV-infected patients under conditions of standard treatment. Our results contribute to the growing body of evidence implicating PIs in the development of blood lipid abnormalities. In conjunction with the predominance or men, high rates of smoking, and aging of the treated HIV-positive population, elevated lipoproteins and triglycerides may mean that patients such as these are at elevated risk for cardiovascular events in the future.

Ritonavir Decreases the Nonrenal Clearance of Digoxin in Healthy Volunteers with Known MDR1 Genotypes

Our objective was to examine the influence of ritonavir on P-glycoprotein (P-gp) activity in humans by characterizing the effect of ritonavir on the pharmacokinetics of the P-gp substrate digoxin in individuals with known MDR1 genotypes. Healthy volunteers received a single dose of digoxin 0.4 mg orally before and after 14 days of ritonavir 200 mg twice daily. After each digoxin dose blood and urine were collected over 72 hours and analyzed for digoxin. Digoxin pharmacokinetic parameter values were determined using noncompartmental methods. MDR1 genotypes at positions 3435 and 2677 in exons 26 and 21, respectively, were determined using PCR-RFLP analysis. Ritonavir increased the digoxin AUC(0-72) from 26.20 +/- 8.67 to 31.96 +/- 11.24 ng x h/mL (P = 0.03) and the AUC(0-8) from 6.25 +/- 1.8 to 8.04 +/- 2.22 ng x h/mL (P = 0.02) in 12 subjects. Digoxin oral clearance decreased from 149 +/- 101 mL/h x kg to 105 +/- 57 mL/h x kg (P = 0.04). Other digoxin pharmacokinetic parameter values, including renal clearance, were unaffected by ritonavir. Overall, 75% (9/12) of subjects had higher concentrations of digoxin after ritonavir administration. The majority of subjects were heterozygous at position 3435 (C/T) (6 subjects) and position 2677 (G/T,A) (7 subjects); although data are limited, the effect of ritonavir on digoxin pharmacokinetics appears to occur across all tested MDR1 genotypes. Concomitant low-dose ritonavir reduced the nonrenal clearance of digoxin, thereby increasing its systemic availability. The most likely mechanism for this interaction is ritonavir-associated inhibition of P-gp. Thus, ritonavir can alter the pharmacokinetics of coadministered medications that are P-gp substrates.