Images in clinical medicine. Buffalo hump in a patient with the acquired immunodeficiency syndrome

Tolerability and safety of HIV protease inhibitors in adults

Antiretroviral drugs are associated with both short-term and long-term adverse events. Like other HIV drugs, protease inhibitors (PIs) may affect metabolic processes influencing body shape and body tissue composition, appearance, bone integrity, and cardiovascular status. However, numerous confounding variables including age, cigarette smoking, body mass index (BMI), duration of HIV infection, degree of immunodeficiency, concomitant antiretroviral agents, extent of previous treatment, and duration of treatment all blur the relationship between PI use and adverse events. Recent data suggest that the early PIs appear to have greater effects on such surrogate markers of disease risk as insulin resistance and cholesterol and triglyceride levels than the recently developed PIs. These data also suggest that evaluation of PIs as a class should be reconsidered and that it is probably not appropriate to extrapolate safety data obtained from individuals treated with first-generation agents in the era of potent combination antiretroviral therapy to those treated with recently developed PIs. Because PIs remain a critical component of successful antiretroviral therapy, evaluation of potential long-term complications with prolonged PI use is essential, as is delineation of the significant differences in safety profiles among individual PIs.

Lipodystrophy Syndrome: The Morphologic and Metabolic Effects of Antiretroviral Therapy in HIV Infection

Widespread use of highly active antiretroviral therapy (HAART) to manage HIV infection is now associated with the development of lipodystrophy syndrome. This syndrome is a combination of such morphologic and metabolic changes as hyperlipidemia, fat redistribution, and insulin resistance. Although many of the long-term effects of HAART have not been fully recognized, it is thought that lipodystrophy syndrome may now contribute to early-onset hypercholesterolemia, heart disease, and diabetes, and may have a negative psychological impact on the individual living with HIV infection.

Advances in HIV treatment and treatment toxicities

Among the different classes and complexities of antiretroviral regimens, maximal viral suppression, sustained durability, increased CD4 count, decreased evolving resistance, and fewer side effects combined with increased compliance resulting in decreased morbidity and mortality remain the goals of therapy. Serial viral load measurements help best guide the direction of therapy. According to the CDC 20% fewer people died of HIV in 1998 compared to 1997 in the United States. HAART, although expensive (sometimes exceeding $20,000 per year), is not readily available to 95% of the estimated 36 million HIV-infected people in the world. HAART therapy commonly consists of two NRTIs and a protease inhibitor, but other combination regimens exist. The disadvantage of HAART therapy is that antiretroviral agents are not virucidal, thus eradication with these drug cocktails cannot be achieved. When HAART therapy is stopped, viral loads return to pre-treatment levels. New drug classes under investigation may completely prevent fusion between the HIV virus and healthy cells. For now, the epidemic can only be controlled with good public awareness, such as education, condom use, or abstinence. Because a cure does not seem immediately foreseeable, an effective prophylactic vaccine may afford protection. Defined treatment regimens exist for occupational postexposure prophylaxis. Ultimately, an expert in the field should be involved in manipulating drug regimens; however, dermatologists remain an integral part of the health care team because most HIV patients experience cutaneous manifestations related either to their HIV or to their drug therapy.

Spinal epidural lipomatosis in a human immunodeficiency virus-positive patient receiving steroids and protease inhibitor therapy

We describe a patient who became cushingoid as a result of receiving steroid therapy for thrombocytopenia purpura and who then developed spinal epidural lipomatosis 4 months after he started receiving ritonavir as part of his therapy for human immunodeficiency virus infection. We believe that ritonavir may have contributed to the development of epidural lipomatosis and that clinicians should be aware of this possible association.

Antiviral agents

The potential severity of many viral infections and the lack of appropriate treatment for these diseases have been a source of endless frustration and helplessness for clinicians. The newly developed field of antiviral therapy is expanding at an astounding rate, with new discoveries each day. Although physicians are not yet able to cure many of the viral infections, such as HSV, HIV, and CMV, a means of controlling them is available. It is hoped that the research and investigations currently under way will lead to a future era of antiviral drugs that will be able to eradicate these diseases.

Metabolic disorders among HIV-infected patients treated with protease inhibitors: a review

Currently available protease inhibitors are associated with development of a group of metabolic disorders. These include a peripheral lipodystrophy syndrome in which there is fat wasting in the face, arms, and legs; fat accumulation in the abdomen, dorsocervical region, and/or breasts (women only); as well as hyperlipidemia, hypercholesterolemia, and insulin resistance. A review of 15 observational studies and case reports shows that the incidence of the peripheral lipodystrophy syndrome increases with time of exposure to protease inhibitors, with a >60% incidence seen after 1 year of continuous treatment. Protease inhibitors are hypothesized to cause this syndrome by impairing conversion of retinoic acid to cis-9-retinoic acid (leading to impaired peripheral fat storage, sequestration of body fat to central adipocytes, and hyperlipidemia) and by inhibiting low-density lipoprotein receptor-related protein (LRP), thus preventing postprandial chylomicron clearance and further contributing to hyperlipidemia. Recent in vitro data suggest that more than one pathway contributes to the lipodystrophy syndrome and that pathways may differ among protease inhibitors. Although the central fat accumulation, hyperlipidemia, and insulin resistance components of this syndrome may reverse after discontinuation of protease inhibitor therapy, it is not known whether complete normalization of fast-wasted body regions is possible. Prospective controlled studies are needed to define whether protease inhibitors currently under development are less prone to produce the lipodystrophy syndrome.

Prospective study of urinalysis abnormalities in HIV-positive individuals treated with indinavir

Indinavir is a potent protease inhibitor widely used in combination with reverse-transcriptase inhibitors to treat human immunodeficiency virus (HIV) disease. Individuals treated with indinavir are prone to develop urinary complications, including renal colic, renal calculi, lower urinary tract symptoms, and indinavir crystalluria. Although renal stones secondary to indinavir have been described and characterized, little is known about the onset, frequency, and significance of the crystalluria. To document the longitudinal characteristics of indinavir crystalluria and associated urine abnormalities, 54 asymptomatic indinavir-naive HIV-positive individuals had urinalysis testing initially weekly and then monthly during the first year of indinavir treatment. Six hundred eight urinalyses were performed (11 +/- 2 urinalysis/subject), including 579 microscopy examinations performed by a nephrologist (10 +/- 2 examinations/subject). Baseline urinalysis results were essentially normal. After the start of treatment, indinavir crystalluria was frequently observed (67% of subjects). After the first 2 weeks, indinavir crystalluria remained constant at a frequency of approximately 25% of urine sediments examined at each test point. Other urine abnormalities, principally leukocytes (>/=10/high-power field) and casts, were observed in 39% of subjects. These abnormalities were more severe in five subjects, with concomitant increasing serum creatinine levels in three of them. Additional urine findings include the predominance of low pH (</=5. 5 in 72% of urinalyses) and high specific gravity (>/=1.025 in 66% of urinalyses). In conclusion, abnormal urinalysis results were noted frequently during the first year of treatment with indinavir. The main findings were the high proportion of subjects with crystalluria and the relatively high frequency of crystalluria observed consistently throughout. These findings may occasionally be associated with other urine abnormalities, presumably secondary to indinavir crystalluria.

Simvastatin-induced rhabdomyolysis in an HIV-infected patient with coronary artery disease

As greater numbers of human immunodeficiency virus (HIV)-infected individuals live to middle-age and beyond, there is growing concern that elevated cholesterol and lipid values will lead to cardiovascular complications in such patients. Furthermore, several of the highly active antiretroviral therapies (HAART) used to reduce levels of circulating HIV and extend acquired immunodeficiency syndrome (AIDS)-related survival are associated with a rise in plasma lipids. Anecdotal reports suggest such rises may be linked to cardiovascular complications. Herein, we review the case of a 74-year-old HIV-infected man with advanced coronary artery disease. He was prescribed simvastatin for control of hyperlipidemia and within 4 weeks developed muscle pain, proximal muscle weakness, myoglobinuria, and a markedly elevated creatinine phosphokinase (CPK). Simvastatin was discontinued, and rhabdomyolysis improved rapidly with conservative care. This report emphasizes this rare, but potentially significant, side effect of statin anticholesterol agents. Medical providers who prescribe statins must remember to check CPK levels when their HIV-infected patients complain of muscle pain. Discontinuing the offending drug will usually result in rapid diminution of muscle pain and inflammation and improve muscle strength.

HIV-associated lipodystrophy syndrome

Highly active antiretroviral therapy (HAART) for human immunodeficiency virus-1 (HIV-1) and prophylactic therapy for opportunistic infections have increased survival. Adverse effects of HAART include lipid profile alterations, diabetes mellitus, and fat redistribution. These metabolic and physical changes are called the HIV-associated lipodystrophy syndrome. A link to protease inhibitors has been suggested, and more recently to nucleoside reverse transcriptase inhibitors and factors related to duration of HIV-1 infection itself.

Indinavir: a review of its use in the management of HIV infection

Indinavir is a protease inhibitor used in the treatment of patients with HIV infection. Combination antiretroviral therapy with indinavir plus 2 nucleoside reverse transcriptase inhibitors (NRTIs) is associated with greater reductions in viral load, greater increases in CD4+ cell counts, and reduced morbidity and mortality when compared with 2 NRTIs alone. In the landmark clinical trial ACTG 320, the rate of progression to AIDS or death (primary end-point) among zidovudine-experienced patients treated with indinavir, zidovudine and lamivudine was approximately half that of patients who received only zidovudine plus lamivudine (6 vs 11%; p < 0.001). The durability of an indinavir-containing regimen was demonstrated in Merck protocol 035, an ongoing trial in which a significant proportion of patients had sustained viral suppression for up to 3 years. Merck protocol 039, also an ongoing trial, showed a greater effect on surrogate markers of HIV disease progression with indinavir-based triple therapy than with zidovudine plus lamivudine or indinavir monotherapy in patients with advanced disease (median baseline CD4+ count 15 cells/microL). Numerous additional clinical trials have established the beneficial antiviral and immunological effects of indinavir in both antiretroviral-naive and -experienced patients with HIV infection. Indinavir is associated with various drug class-related adverse events, including gastrointestinal disturbances (e.g. nausea, diarrhoea), headache and asthenia/fatigue. A lipodystrophy syndrome has been commonly reported with indinavir and other protease inhibitors combined with NRTIs, but it has also been reported in many protease inhibitor-naive patients, and a definitive causal link has not been established between the syndrome and protease inhibitors. Nephrolithiasis may develop in about 9% of patients receiving indinavir but does not appear to be associated with other protease inhibitors; <0.5% of patients receiving indinavir discontinue the drug because of nephrolithiasis, which may be the extreme end of a continuum of crystal-related renal syndromes. Additional renal problems (e.g. nephropathy) have been reported in small numbers of patients receiving indinavir. In summary, indinavir is a protease inhibitor with well documented efficacy when used as part of combined therapy in patients with HIV infection. Both US and UK treatment guidelines continue to recommend protease inhibitor-based regimens including indinavir as a first-line option. Indinavir is being studied as a twice daily and once daily regimen with a low dosage of ritonavir as a way to alleviate tolerability, drug interaction and patient compliance/adherence issues. Indinavir-containing triple therapy has demonstrated positive effects not only on surrogate markers of disease progression, but also on clinical end-points of mortality and morbidity in patients with HIV disease. Protease inhibitors are a significant advance in the care of patients with HIV infection, and, in an era of evidence-based medicine, indinavir represents an important component of antiretroviral treatment strategies.