Ross G. Hewitt

Abacavir Hypersensitivity Reaction

A hypersensitivity reaction occurs in association with initiation of abacavir therapy as part of combination antiretroviral therapy in approximately 3.7% of patients. The reaction is possibly the result of a combination of altered drug metabolism and immune dysfunction, which is poorly understood. White patients appear to be at higher risk and patients of African descent at lower risk of abacavir hypersensitivity. Clinical management involves supportive measures and discontinuation of abacavir therapy. Rechallenge with abacavir in a hypersensitive patient should be avoided because it might precipitate a life-threatening reaction.

Paromomycin: No More Effective than Placebo for Treatment of Cryptosporidiosis in Patients with Advanced Human Immunodeficiency Virus Infection

To evaluate the efficacy of paromomycin for the treatment of symptomatic cryptosporidial enteritis in human immunodeficiency virus-infected adults, we conducted a prospective, randomized, double-blind, placebo-controlled trial before the widespread introduction of highly active antiretroviral therapy (HAART). Seven units under the auspices of the AIDS Clinical Trials Group enrolled 35 adults with CD4 cell counts of < or = 150/mm(3). Initially, 17 patients received paromomycin (500 mg 4 times daily) and 18 received matching placebo for 21 days. Then all patients received paromomycin (500 mg q.i.d.) for an additional 21 days. Clinical definitions of response were measured by an average number of bowel movements per day in association with concurrent need for antidiarrheal agents that was lower than that before study entry. There was no treatment response during the placebo-controlled phase of the study according to protocol-defined criteria (P=.88). Three paromomycin recipients (17.6%) versus 2 placebo recipients (14.3%) responded completely. Rates of combined partial and complete responses in the paromomycin arm (8 out of 17, 47.1%) and the placebo arm (5 out of 14, 35.7%) of the study were also similar (P=.72). The clinical course of cryptosporidiosis was quite variable. Paromomycin was not shown to be more effective than placebo for the treatment of symptomatic cryptosporidial enteritis. However, inadequate statistical power prevents definitive rejection of the usefulness of paromomycin as therapy for this infection.

Randomized Trial of Itraconazole Oral Solution for Oropharyngeal Candidiasis in HIV/AIDS Patients

PURPOSE Oropharyngeal candidasis (thrush) is the most common opportunistic infection in individuals who are positive for the human immunodeficiency virus (HIV) and those who have progressed to AIDS. Itraconazole has a broad in vitro spectrum of activity, including a wide variety of Candida species. Our study determined the relative efficacy of a new oral solution formulation of itraconazole and fluconazole tablets in the treatment of oropharyngeal candidiasis. PATIENTS AND METHODS This was a prospective randomized, third-party-blind, multicenter trial conducted at 12 centers in the United States. One hundred seventy-nine HIV-positive patients with mycologically documented oropharyngeal candidiasis were treated with itraconazole oral solution 200 mg/ day for 7 or 14 days, or fluconazole tablets 100 mg/day for 14 days. Severity of disease was scored clinically before treatment and at clinical evaluations on days 3, 7, 14, 21, 35, and 42. Semi-quantitative cultures of mouth washings were also obtained on these days. RESULTS Both 14-day and 7-day regimens of itraconazole oral solution were equivalent to fluconazole for most efficacy parameters. The clinical response rate was 97% after 14 days of itraconazole and 87% after 14 days of fluconazole. Itraconazole oral solution given for 7 days was also equivalent to fluconazole treatment for 14 days. Approximately one half of patients in all three groups relapsed by 1 month after completion of treatment. There were few adverse reactions to either drug. CONCLUSION Itraconazole oral solution is well tolerated and offers an alternative at least as effective as fluconazole in the treatment of oropharyngeal candidiasis.

Cocaine Modulates Dendritic Cell-Specific C Type Intercellular Adhesion Molecule-3-Grabbing Nonintegrin Expression by Dendritic Cells in HIV-1 Patients

We report that cocaine may act as cofactor in HIV pathogenesis by increasing dendritic cell-specific C type ICAM-3-grabbing nonintegrin (DC-SIGN) expression on dendritic cells (DC). Our results show that cocaine-using, long-term nonprogressors and normal progressors of HIV infection manifest significantly higher levels of DC-SIGN compared with cocaine-nonusing long-term nonprogressors and normal progressors, respectively. Furthermore, in vitro HIV infection of MDC from normal subjects cultured with cocaine and/or HIV peptides up-regulated DC-SIGN, confirming our in vivo finding. Cocaine, in synergy with HIV peptides, also up-regulates DC-SIGN gene expression by MDC. Furthermore, the cocaine-induced effects were reversed by a D1 receptor antagonist demonstrating the specificity of the reaction. Our results indicate that cocaine exacerbates HIV infection by up-regulating DC-SIGN on DC and these effects are mediated via dysregulation of MAPKs. These data are the first evidence that cocaine up-regulates the expression of DC-SIGN on DC. A better understanding of the role of DC-SIGN in HIV infection may help to design novel therapeutic strategies against the progression of HIV disease in the drug-using population.

Cocaine Differentially Modulates Chemokine Production by Mononuclear Cells from Normal Donors and Human Immunodeficiency Virus Type 1-Infected Patients

ABSTRACT Earlier studies have supported a significant role for cocaine in the susceptibility to and the progression of human immunodeficiency virus type 1 (HIV-1) infection. Recently, several unique HIV-1 entry coreceptors (e.g., CCR5 and CCR3) and a trio of HIV-1-specific suppressor chemokines, namely, RANTES (regulated-upon-activation T expressed and secreted), macrophage inflammatory protein 1α (MIP-1α) and MIP-1β, were identified. Although cocaine has been linked to the immunopathogenesis of HIV-1 infection, the corresponding cellular and molecular mechanism(s) have not been well defined. We hypothesize that cocaine mediates these pathologic effects through the downregulation of HIV-1-suppressing chemokines and/or upregulating HIV-1 entry coreceptors in HIV-1-infected subjects, resulting in disease progression to AIDS. Our results show that cocaine selectively downregulates endogenous MIP-1β secretion by normal peripheral blood mononuclear cells (PBMC), while cocaine did not affect the MIP-1β production by PBMC from AIDS patients. Cocaine also selectively suppresses lipopolysaccharide-induced MIP-1β production by PBMC from HIV-infected patients. Further, cocaine significantly downregulates endogenous MIP-1β gene expression, while it upregulates HIV-1 entry coreceptor CCR5 by normal PBMC. These studies suggests a role for cocaine as a cofactor in the pathogenesis of HIV infection and support the premise that cocaine increases susceptibility to and progression of HIV-1 infection by inhibiting the synthesis of HIV-1 protective chemokines and/or upregulating the HIV-1 entry coreceptor, CCR5.

Effects of Grapefruit Juice on Pharmacokinetic Exposure to Indinavir in HIV‐Positive Subjects

The objective of this study was to determine the effects of double‐strength grapefruit juice on gastric pH and systemic bioavailability of indinavir in HIV‐infected subjects receiving indinavir. Fourteen HIV‐infected subjects took 800 mg of indinavir with 6 ounces (180 ml) of water or double‐strength grapefruit juice. Gastric pH was measured and blood samples were collected for 5 hours after indinavir dosing. Grapefruit juice increased the mean gastric pH (from 1.39 ± 0.4 to 3.20 ± 0.3; p < 0.05) and slightly delayed the absorption of indinavir (tmax increased from 1.12 ± 0.8hto 1.56± 0.6 h; p < 0.05). However, there were no significant differences in indinavir exposure. Cmax was 16.7 ± 7.3 μ with water versus 13.9 ± 4.2 μ with grapefruit juice (p = NS), and AUC0–8 was 37.5 ± 19 with water versus 36.9 ± 15 with grapefruit juice (p = NS). The authors concluded that concomitant administration of grapefruit juice increases gastric pH and delays indinavir absorption but does not uniformly affect the systemic bioavailability of indinavir in HIV‐infected subjects.

Comparison of Measured and Estimated Creatinine Clearance in Patients With Advanced HIV Disease

Study Objective. To assess the accuracy of five creatinine clearance equations in predicting measured creatinine clearance in hospitalized patients with human immunodeficiency viral (HIV) infection.

Zidovudine Pharmacokinetics in HIV-Positive Women During Different Phases of the Menstrual Cycle

Study Objective. To examine the pharmacokinetics of zidovudine during the menstrual cycle in human immunodeficiency virus‐ (HIV‐) positive women.

The Effects of Once‐Daily Saquinavir/Minidose Ritonavir on the Pharmacokinetics of Methadone

Twelve methadone‐maintained HIV‐negative subjects were given saquinavir/ritonavir (SQV/rtv) 1600 mg/100 mg once daily for 14 days. Pharmacokinetic evaluations of total and unbound methadone enantiomers (R and S) were conducted before and after SQV/rtv. SQV/rtv was well tolerated, with no ACTG Grade 3–4 adverse events, no evidence of sedation, and no changes in methadone dose. For R‐methadone (active isomer), Cmax, AUC0–24 h, and Cmin were unchanged, but percent unbound 4 hours after dosing was reduced by 12%. For S‐methadone, no differences in pharmacokinetic parameters of total drug were seen, but unbound concentrations were reduced by 15% and 21% at 4 and 24 hours after dosing, respectively. SQV trough concentrations exceeded the anticipated EC50 (50 ng/mL) in 10/12 subjects, persisting for at least 6 hours after the final dose in 4/6 subjects. Once‐daily SQV/rtv in methadone‐maintained subjects is safe and not associated with any clinically significant interaction with methadone during 14 days of concomitant administration.

Emotional distress among HIV-positive individuals: the roles of acute negative life events and psychological diatheses

The present study investigated the impact of negative life events and psychological diatheses (neuroticism, low self-esteem, and dysfunctional attitudes) on emotional distress among HIV-positive patients. Fifty-two participants completed questionnaires assessing acute stressful life events, psychological diatheses, perceived stress, and depressive symptoms. The following hypotheses were tested: (a) negative life events would predict depressive symptoms and perceived stress; (b) HIV-specific life events would be more strongly associated with depressive symptoms and perceived stress than general life events; and (c) psychological diatheses would moderate the relationship between acute life events and depressive symptoms, as well as the relationship between life events and perceived stress. Results indicated that both general and HIV-specific life events predicted depressive symptoms and perceived stress. However, no support was found for the hypothesis that HIV-related life events would be more potent. Psychological diatheses moderated the impact of life events on perceived stress, such that life events had a greater impact on those with lower levels of vulnerability. These results remained significant after controlling for biological markers of disease progression.