Safety of oral versus intravenous hydration during induction therapy with intravenous foscarnet in AIDS patients with cytomegalovirus infections

We undertook a study to compare the safety of intravenous (i.v.) versus oral hydration to prevent nephrotoxicity associated with the use of foscarnet for induction therapy of cytomegalovirus (CMV) infection in HIV-infected persons. Patients, given foscarnet at a dose of 90 mg/kg every 12 h, were randomized to receive either i.v. or oral hydration. Thirty-seven patients were given i.v. hydration and 44 were given oral hydration. Median duration of therapy for both groups was 17 days. There was no difference between the 2 groups in either serious adverse events or rise of creatinine to > or = 2.0 mg/dl. However, serum creatinine, while generally remained within normal limits, increased more in patients who received oral hydration after 10 days of therapy (significant only by slope analysis, P < 0.05). Although i.v. hydration provided better protection against nephrotoxicity, oral hydration was relatively safe and convenient provided that creatinine clearance (CrCl) is monitored closely.

Analysis of telomere length and thymic output in fast and slow/non-progressors with HIV infection

There are two models for CD4+ T-cell depletion leading to AIDS: a kinetic model and an immune suppression model. In the kinetic model, direct cell killing due to viral replication results in a continuous demand for CD4+ T-cells, which eventually exhausts their capacity for renewal by proliferative mechanisms. In the immune suppression model, CD4+ T-cell decline is due to an indirect global inhibitory effect of the virus on uninfected immune cell function. In order to address differences in the two models, we investigated proliferative history and thymic output in PBMC from the GRIV cohort of fast (FP) and slow/non-progressors (S/NP), and uninfected controls. Proliferative history and thymic output were assessed by measurement of mean telomeric restriction fragment (TRF) length and T-cell receptor Rearrangement Excision Circles (TREC) levels, respectively. Mean TRF lengths were significantly shorter in S/NP (n = 93, 7.59 +/- 0.11 kb) and FP (n = 42, 7.25 +/- 0.15 kb) compared to controls (n = 35, 9.17 +/- 0.19 kb). Mean TRF length in PBMC (n = 9, 7.32 +/- 0.31 kb) and CD4+ enriched fractions (n = 9, 7.41 +/- 0.30 kb) from a subset of non-GRIV HIV-1 infected samples were also significantly smaller than PBMC (n = 8, 9.77 +/- 0.33 kb) and CD4+ fractions (n = 8, 9.41 +/- 0.32 kb) from uninfected controls. Rates of telomeric shortening, however, were similar among S/NP (n = 93, -45 +/- 20 bp/yr), FP (n = 42, -41 +/- 14 bp/yr) and controls (-29 +/- 17 bp/yr). Paralleling differences observed in mean TRF length, TREC levels were significantly reduced in S/NP (n = 10, 3,433 +/- 843 mol/mu and FP (n = 8, 1,193 +/- 413) compared to controls (n = 15, 22,706 +/- 5,089), indicative of a defect in thymopoiesis in HIV-1 infection. When evaluated in the context of reduced thymopoiesis, the difference in mean TRF length between S/NP and controls (1.58 +/- 0.30 kb) is similar to that observed between memory and naïve T-cells (1.4 +/- 0.1 kb), and may reflect perturbations in the peripheral T-cell population due to a decline in thymic output of naïve T-cells rather than increased turnover. Based on the different clinical criteria used to select S/NP and FP, the sight difference in TREC between these two groups suggests the threshold for pathogenesis as a result of naïve T-cell depletion may be quite low, and incremental increases in thymic output may yield substantial clinical results. Future studies regarding therapeutic vaccination, specifically with HIV-1 Tat targeted anti-immunosuppressive vaccines, should address the defect in thymic output in HIV-1 infection by using TREC analysis as a rapid method for biological evaluation.

AIDS-related Kaposi's sarcoma: a phase II study of liposomal doxorubicin. The TLC D-99 Study Group

TLC D-99 is a unique liposomal formulation of doxorubicin that consists of phosphatidyl choline/cholesterol. The objectives of the study were to evaluate safety and efficacy of two doses of TLC D-99 in the treatment of patients with AIDS-related Kaposi's Sarcoma (KS). Forty HIV-infected persons with biopsy-proven KS were randomized to receive TLC D-99 at doses of either 10 (low) or 20 (high) mg/m2 every 2 weeks. Patients assigned to the low-dose arm could be escalated to the high-dose arm if their KS progressed after 3 cycles of therapy. Median age was 35 years (range, 26-47) and median CD4 count was 13 (range, 0-440). Nineteen patients were assigned to receive the low dose, and 21 patients were assigned to the high dose. Partial response occurred in 15% (6 of 40) of the patients or in 5% (1 of 19) and 24% (5 of 21) in the low- and high-dose arms, respectively; stable disease was observed in 65% (26 of 40) or in 68% (13 of 19) and 62% (13 of 21) in the low and high doses, respectively. Neutropenia was the major toxicity and was observed in 68 and 81% of patients with the low- and high-dose arms, respectively; grade 4 neutropenia was observed in 16 and 14%, respectively. Mild alopecia was noted in only 8%. Therefore, TLC D-99 is active against AIDS-related KS, and the response is dose-dependent.

Cytomegalovirus infection in patients with HIV infection

Cytomegalovirus (CMV) is responsible for the most common viral opportunistic infection in persons with acquired immunodeficiency virus syndrome (AIDS). Clinical disease due to CMV has been recognized in up to 40% of patients with advanced HIV disease. The most common presentation is retinitis, although colitis, esophagitis, pneumonitis and neurological disorders are also reported frequently. CMV retinitis is usually diagnosed clinically, and serological testing for CMV immunoglobulin is useful to support the diagnosis. Parts of the gastrointestinal tract (esophagus and colon) are the most common extraocular sites of CMV infection in AIDS patients. Therapy with systemic agents, including intravenous ganciclovir, intravenous foscarnet, and intravenous cidofovir, is effective. Ganciclovir is associated mainly with hematological toxicity, while foscarnet and cidofovir are nephrotoxic. Intravitreal injections with these antiviral agents are also effective, but inconvenient, and there is a need for repeated injections. Intraocular implants that slowly release ganciclovir have been effective for both acute therapy and long-term maintenance, but the occurrence of contralateral ocular and extraocular disease is a serious concern. New agents, as for example an anti-sense agent against CMV, appear promising.

Atovaquone compared with dapsone for the prevention of Pneumocystis carinii pneumonia in patients with HIV infection who cannot tolerate trimethoprim, sulfonamides, or both. Community Program for Clinical Research on AIDS and the AIDS Clinical Trials Group

BACKGROUND

Although trimethoprim-sulfamethoxazole is the drug of choice for the prevention of Pneumocystis carinii pneumonia, many patients cannot tolerate it and must switch to an alternative agent.

METHODS

We conducted a multicenter, open-label, randomized trial comparing daily atovaquone (1500-mg suspension) with daily dapsone (100 mg) for the prevention of P. carinii pneumonia among patients infected with the human immunodeficiency virus who could not tolerate trimethoprim-sulfamethoxazole. The median follow-up period was 27 months.

RESULTS

Of 1057 patients enrolled, 298 had a history of P. carinii pneumonia. P. carinii pneumonia developed in 122 of 536 patients assigned to atovaquone (15.7 cases per 100 person-years), as compared with 135 of 521 in the dapsone group (18.4 cases per 100 person-years; relative risk for atovaquone vs. dapsone, 0.85; 95 percent confidence interval, 0.67 to 1.09; P=0.20). The relative risk of death was 1.07 (95 percent confidence interval, 0.89 to 1.30; P=0.45), and the relative risk of discontinuation of the assigned medication because of adverse events was 0.94 (95 percent confidence interval, 0.74 to 1.19; P=0.59). Among the 546 patients who were receiving dapsone at base line, the relative risk of discontinuation because of adverse events was 3.78 for atovaquone as compared with dapsone (95 percent confidence interval, 2.37 to 6.01; P<0.001); among those not receiving dapsone at base line, it was 0.42 (95 percent confidence interval, 0.30 to 0.58; P<0.001).

CONCLUSIONS

Among patients who cannot tolerate trimethoprim-sulfamethoxazole, atovaquone and dapsone are similarly effective for the prevention of P. carinii pneumonia. Our results support the continuation of dapsone prophylaxis among patients who are already receiving it. However, among those not receiving dapsone, atovaquone is better tolerated and may be the preferred choice for prophylaxis against P. carinii pneumonia.

Fumagillin analog in the treatment of Kaposi's sarcoma: a phase I AIDS Clinical Trial Group study. AIDS Clinical Trial Group No. 215 Team

PURPOSE

Angiogenesis is a major component of Kaposi's sarcoma (KS) and a critical process in tumor growth. The present study was designed primarily to test the toxicity and pharmacokinetics (PK) of the angiogenesis inhibitor TNP-470 and secondarily to evaluate tumor response in patients with early AIDS-related KS.

PATIENTS AND METHODS

Patients with AIDS-related KS were required to have cutaneous disease with > or = 5 measurable lesions and no evidence of pulmonary, symptomatic gastrointestinal, or acutely life-threatening KS. Thirty-eight patients received TNP-470 by weekly intravenous infusion over 1 hour at one of six dose levels for up to 24 weeks.

RESULTS

The dose levels tested included 10, 20, 30, 40, 50 and 70 mg/m2. Median CD4 count was 24 cells/microl (range, 0 to 460). Fourteen patients (36%) had > or = 50 cutaneous lesions and 19 (49%) had oral lesions. Adverse events included neutropenia (n = 2), hemorrhage (n = 3), and urticaria (n = 1). PK studies showed wide interpatient and intrapatient variability. Elimination half-life values were short (range, 0.01 to 0.61 hours). Seven patients (18%) achieved a partial response. The median time to partial response was 4 weeks (range, 2 to 25), and the median duration of response was 11 weeks (range, 3 to 26+).

CONCLUSION

TNP-470, administered as a weekly, 1-hour infusion to patients with early AIDS-KS is well-tolerated at doses up to and including the highest dose tested. Tumor responses were observed in a substantial number of cases and occurred at various dose levels. TNP-470 should be evaluated further in patients with AIDS-KS as a single agent and in combination with other biologic response modifiers in early disease or after initial response to cytotoxic chemotherapy.

Pseudomonas aeruginosa bacteremia in patients with AIDS

Twenty-seven episodes of Pseudomonas aeruginosa bacteremia in 21 patients with AIDS were evaluated at the Mount Sinai Medical Center in 1987-1992. Of 21 primary episodes, 12 were acquired in the community, 8 were nosocomial, and one was acquired in a nursing home. Sources of bacteremia (i.e., sites of infection; n = 30) included the lungs (12 cases) an indwelling vascular catheter (9), and the upper respiratory tract (5, including 2 cases of sinusitis, 2 cases of malignant external otitis, and 1 case of epiglottis/pharyngeal cellulitis); in 4 cases the source was unknown. White blood cell counts ranged from 0.1 to 26.2 (mean, 4.32) x 10(3)/mm3; in 19 of 26 cases, the absolute neutrophil count was > 1 x 10(3)/mm3. With the exclusion of primary episodes of bacteremia that resulted in death, the rate of relapse was 33.3% (5 of 15 cases). Mortality for the 25 evaluable episodes of bacteremia was 40% (32% for primary infection and 80% for relapse; P = .06); 52.6% of evaluable patients (10 of 19) ultimately died of P. aeruginosa bacteremia. The institution of appropriate therapy at presentation did not positively affect outcome. Rates of response were higher among episodes treated with a drug combination (an antipseudomonal beta-lactam or monobactam antibiotic plus an aminoglycoside) than among those treated with a single agent (P = .036).

Phase II dose-ranging trial of foscarnet salvage therapy for cytomegalovirus retinitis in AIDS patients intolerant of or resistant to ganciclovir (ACTG protocol 093). AIDS Clinical Trials Group of the National Institute of Allergy and Infectious Diseases

OBJECTIVE

To document response to foscarnet salvage therapy in patients with cytomegalovirus (CMV) retinitis who are intolerant of or resistant to ganciclovir.

METHODS

Patients with AIDS and CMV retinitis who had documented hematologic intolerance or resistance to ganciclovir therapy received an induction course of foscarnet, 60 mg/kg every 8 h for 14 days, and subsequent chronic maintenance foscarnet therapy at a daily dose of 60, 90 or 120 mg/kg/day. The first 87 patients were randomly assigned to receive maintenance foscarnet at a dose of 60 or 90 mg/kg/day; all subsequent patients were assigned a maintenance dose of 120 mg/kg/day.

RESULTS

A total of 156 evaluable patients were enrolled. Median time to retinitis progression and survival did not differ significantly among groups assigned to different maintenance foscarnet doses. Among patients with retinitis progression documented ophthalmologically occurring at < or = 2 week intervals, despite optimal doses of ganciclovir, time to progression on foscarnet therapy was a median 8 weeks at all doses studied. By dose assignment, there were no significant differences in serious drug-associated toxicity, although trends toward increased renal and hypocalcemic adverse events were observed at higher maintenance doses.

CONCLUSION

In patients intolerant of ganciclovir, salvage foscarnet therapy resulted in a longer time to retinitis progression than reported previously in historic controls who terminated ganciclovir therapy. In patients who exhibited clinical resistance to ganciclovir, foscarnet appeared to have efficacy in controlling retinitis. No significant differences in either efficacy or toxicity were observed in the range of foscarnet maintenance doses studied.

Intramuscular pentamidine for the prevention of Pneumocystis carinii pneumonia in patients infected with human immunodeficiency virus

We retrospectively reviewed the charts of 96 patients infected with human immunodeficiency virus (HIV) who received intramuscular pentamidine for the prevention of Pneumocystis carinii pneumonia (PCP). These patients, all of whom had either a history of PCP or a CD4 lymphocyte count of < or = 0.2 x 10(9)/L, were intolerant of sulfa drugs, neutropenic, or intolerant of aerosolized treatment. Intramuscular pentamidine was given monthly by the Z-track technique at a dosage of 300 mg (4 mg/kg if the patient weighed < 50 kg). During a total of 350 months of primary prophylaxis in 47 patients and 426 months of secondary prophylaxis in 49 patients, only three cases of PCP occurred. More than 73% of the patients were receiving zidovudine concomitantly. Adverse reactions to intramuscular pentamidine included two episodes of hypotension, three of sterile abscess, two of glucose intolerance, and one of asymptomatic hypoglycemia. The administration of intramuscular pentamidine by the Z-track technique for PCP prophylaxis appears to be highly effective and minimally toxic.

Systemic antiviral drugs used in ophthalmology

Over the past two decades, the recognition of viral enzymes and proteins that can serve as molecular targets of drugs has revolutionized the treatment of viral infections. Beginning with acyclovir, a number of systemically administered agents which are both relatively safe and effective for the treatment of herpetic infections and human immunodeficiency virus (HIV) infections have become widely available. Because of increased numbers of herpes virus infections, as well as the rising epidemic of HIV infections, the ophthalmologist is, more likely than ever before to be involved in the treatment of severe and frequent ocular infections caused by herpes viruses. In addition, the acute retinal necrosis (ARN) syndrome has been demonstrated to be caused by herpes viruses and a once rare retinal infection caused by cytomegalovirus is common in patients with the acquired immunodeficiency syndrome (AIDS). In this article, four systemic antiviral drugs (Vidarabine, Acyclovir, Ganciclovir, and Foscarnet) that have demonstrated usefulness in the treatment of ophthalmic disease are reviewed in detail with regard to their mechanisms, applications, effectiveness, and side effects.