Curbing the diabetes and tuberculosis co-epidemic: the potential role of China

China has been playing an increasingly important role in global health in recent decades. Substantial progress and reform has been made in the country's health care system, but China still hosts one third of the world's diabetes mellitus (DM) patients and one fifth of the world's tuberculosis (TB) patients. Recent economic and public health advancements have provided tools for new drug development and facilitated the implementation of novel strategies. However, a unique set of challenges exist, including regulatory barriers, ethical concerns and the lack of a unified system and approaches across disease areas. This article analyses the current disease situation in China and discusses China's potential role in the global battle against the TB and DM co-epidemic.

Conducting high-quality tuberculosis clinical trials in China: opportunities and challenges

Tuberculosis (TB) is an ancient disease that is a devastating threat to public health. As the country with the second highest number of TB cases and the highest number of multidrug-resistant TB cases in the world, China is now striving to be at the forefront of TB research and drug development. This article is based on the observations made by the authors during the recent partnership initiative between the National Institutes of Health and the Chinese TB community, as well as an extensive literature review. The article examines the advantages and challenges of conducting large-scale international multicenter TB clinical trials in China. China is becoming an excellent location for new TB drug trials, especially in collaboration with international organizations that bring considerable technical assistance, quality control, training, and oversight with these partnerships.

Peripheral and visceral fat changes following a treatment switch to a non-thymidine analogue or a nucleoside-sparing regimen in HIV-infected subjects with peripheral lipoatrophy: results of ACTG A5110

BACKGROUND

Switching a thymidine analogue to a non-thymidine analogue or changing to a nucleoside-sparing regimen has been shown to partially reverse peripheral lipoatrophy. The current study evaluated both approaches.

METHODS

Subjects at 15 AIDS Clinical Trial Group sites receiving thymidine analogue stavudine- or zidovudine-containing regimens with plasma HIV RNA < or =500 copies/mL and lipoatrophy were prospectively randomized to: (i) switch the thymidine analogue to abacavir; (ii) discontinue all antiretrovirals and switch to lopinavir/ritonavir plus nevirapine (LPV/r+NVP); or (iii) delay switching for 24 weeks (ClinicalTrials.gov identifier: NCT00028314). Single-slice computer tomography of mid-thigh and abdominal fat and metabolic and virological/immunological parameters were measured at baseline and weeks 24 and 48.

RESULTS

Among the 101 patients enrolled, there were significant subcutaneous thigh fat and subcutaneous abdominal tissue (SAT) increases over time and decreases in visceral adipose tissue to total adipose tissue (VAT:TAT) ratios for both interventions, and a decrease in VAT for abacavir. CD4 increased in the LPV/r+NVP arm. LPV/r+NVP had a significantly shorter time to grade 3 or higher toxicity (P = 0.007), but discontinuation rates were similar. Glucose levels did not change, but insulin decreased in the LPV/r+NVP arm. Lipids tended to increase in the LPV/r+NVP arm.

CONCLUSIONS

Switching stavudine or zidovudine to a non-thymidine analogue or changing to a nucleoside reverse transcriptase inhibitor-sparing regimen is associated with qualitatively similar improvements in thigh fat, SAT and VAT:TAT ratio at 48 weeks. Abacavir also resulted in VAT reductions and LPV/r+NVP resulted in CD4 count increases.

Emergence of resistance to fluconazole as a cause of failure during treatment of histoplasmosis in patients with acquired immunodeficiency disease syndrome

In sequential clinical trials of treatment for histoplasmosis in patients with acquired immunodeficiency syndrome, therapy with fluconazole failed in a higher proportion of patients than did therapy with itraconazole. To determine the cause for failure with fluconazole, antifungal susceptibility testing that used modified National Committee on Clinical Laboratory Standards procedures was performed on all baseline and failure isolates. Failure occurred more frequently in patients with baseline isolates with fluconazole minimum inhibitory concentrations (MICs) > or =5 microg/mL versus lower MICs; 29% versus 3%, respectively. There was at least a 4-fold increase in fluconazole MIC in the isolates from 10 (59%) of 17 patients for whom paired pretreatment and failure or relapse isolates were available. Cross-resistance to itraconazole was not seen. In conclusion, fluconazole is less active than itraconazole for Histoplasma capsulatum and induces resistance during therapy, which accounted for treatment failure in some patients.

A prospective study of discontinuing primary and secondary Pneumocystis carinii pneumonia prophylaxis after CD4 cell count increase to > 200 x 106 /l

OBJECTIVE

To assess the incidence of Pneumocystis carinii pneumonia (PCP) after discontinuation of either primary or secondary prophylaxis.

DESIGN

This was a prospective, non-randomized, non-blinded study.

SETTING

Twenty-five University-based AIDS Clinical Trials Group units.

PARTICIPANTS

Participants either had a CD4 cell count < or = 100 x 106/l at any time in the past and no history of confirmed PCP (group I; n = 144), or had a confirmed episode of PCP > or = 6 months prior to study entry (group II; n = 129). All subjects had sustained CD4 cell counts > 200 x 106/l in response to antiretroviral therapy.

INTERVENTIONS

Subjects discontinued PCP prophylaxis within 3 months or at the time of study entry. Evaluations for symptoms of PCP and CD4 cell counts were performed every 8 weeks. Prophylaxis was resumed if two consecutive CD4 cell counts were < 200 x 106/l.

MAIN OUTCOME MEASURE(S)

The main outcome was development of PCP.

RESULTS

No cases of PCP occurred in 144 subjects (median follow-up, 82 weeks) in group I or in the 129 subjects (median follow-up, 63 weeks) in group II (95% upper confidence limits on the rates of 1.3 per 100 person-years and 1.96 per 100 person-years for groups I and II, respectively). Eight subjects (five in group I and three in group II) resumed PCP prophylaxis after two consecutive CD4 cell counts < 200 x 106/l.

CONCLUSIONS

The risk of developing initial or recurrent PCP after discontinuing prophylaxis is low in HIV-infected individuals who have sustained CD4 cell count increases in response to antiretroviral therapy. Neither lifelong primary nor secondary PCP prophylaxis is necessary.

Clearance of fungal burden during treatment of disseminated histoplasmosis with liposomal amphotericin B versus itraconazole

Animal studies have shown that fungal burden correlates with survival during treatment with new antifungal therapies for histoplasmosis. The purpose of this report is to compare the clearance of fungal burden in patients with histoplasmosis treated with liposomal amphotericin B versus itraconazole. In two separate closed clinical trials that evaluated the efficacy of liposomal amphotericin B and itraconazole treatment of disseminated histoplasmosis in patients with AIDS, blood was cultured for fungus and blood and urine were tested for Histoplasma antigen. The clinical response rates were similar; 86% with liposomal amphotericin B (n = 51) versus 85% with itraconazole (n = 59). Of the patients with positive blood cultures at enrollment, after 2 weeks of therapy cultures were negative in over 85% of the liposomal amphotericin B group versus 53% of the itraconazole group (P = 0.0008). Furthermore, after 2 weeks, median antigen levels in serum fell by 1.6 U in the liposomal amphotericin B group versus 0.1 U in the itraconazole group (P = 0.02), and those in urine fell by 2.1 U in the liposomal amphotericin B group and 0.2 U in the itraconazole group (P = 0.0005). The more rapid clearance of fungemia supports the use of liposomal amphotericin B rather than itraconazole for initial treatment of moderately severe or severe histoplasmosis.

Tolerance and pharmacokinetic interactions of rifabutin and azithromycin

This multicenter study evaluated the tolerance and potential pharmacokinetic interactions between azithromycin and rifabutin in volunteers with or without human immunodeficiency virus infection. Daily dosing with the combination of azithromycin and rifabutin was poorly tolerated, primarily because of gastrointestinal symptoms and neutropenia. No significant pharmacokinetic interactions were found between these drugs.

Dose-escalation, phase I/II study of azithromycin and pyrimethamine for the treatment of toxoplasmic encephalitis in AIDS

OBJECTIVE

To assess the safety, tolerance and activity of increasing doses of azithromycin in combination with pyrimethamine for the treatment of toxoplasmic encephalitis (TE) in patients with AIDS.

DESIGN

A phase I/II dose-escalation study of oral azithromycin in combination with pyrimethamine.

SETTING

Eight clinical sites in the United States.

PATIENTS

Forty-two adult HIV-infected patients with confirmed or presumed acute TE.

METHODS

Patients were enrolled into three successive cohorts receiving azithromycin 900, 1200 and 1500 mg a day with pyrimethamine as induction therapy. The induction period was 6 weeks followed by 24 weeks of maintenance therapy.

MAIN OUTCOME MEASURES

Patient response was evaluated clinically and radiologically.

RESULTS

Of the 30 evaluable patients, 20 (67%) responded to therapy during the induction period. Ten experienced disease progression. Of the 15 patients who received maintenance therapy, seven (47%) relapsed. Six patients discontinued treatment during the induction period as a result of reversible toxicities. Treatment-terminating adverse events occurred most frequently among the patients receiving the 1500 mg dose.

CONCLUSION

The combination of azithromycin (900-1200 mg a day) and pyrimethamine may be useful as an alternative therapy for TE among patients intolerant of sulfonamides and clindamycin, but maintenance therapy with this combination was associated with a high relapse rate. The combination was safe, but low-grade adverse events were common.

Discontinuation of Mycobacterium avium complex prophylaxis in patients with antiretroviral therapy-induced increases in CD4+ cell count. A randomized, double-blind, placebo-controlled trial. AIDS Clinical Trials Group 362 Study Team

BACKGROUND

Patients infected with HIV who experience increases in CD4(+) cell counts are at reduced risk for opportunistic infections. However, the safety of discontinuing prophylaxis against Mycobacterium avium complex has been uncertain.

OBJECTIVE

To compare the rate of M. avium complex infection in patients with increased CD4(+) cell counts who receive azithromycin and those receiving placebo.

DESIGN

Randomized, double-blind, placebo-controlled trial.

SETTING

29 university-based clinical centers in the United States.

PARTICIPANTS

643 HIV-1-infected patients with a previous CD4(+) cell count less than 0.05 x 10(9) cells/L and a sustained increase to greater than 0.10 x 10(9) cells/L during antiretroviral therapy.

INTERVENTION

Azithromycin, 1200 mg once weekly (n = 321), or matching placebo (n = 322).

MEASUREMENTS

Mycobacterium avium complex cultures, CD4(+) cell counts, and clinical evaluations for AIDS-defining illnesses and bacterial infections were done every 8 weeks. Plasma HIV-1 RNA levels were measured at 16-week intervals.

RESULTS

During follow-up (median, 16 months), 2 cases of M. avium complex infection were reported among the 321 patients assigned to placebo (incidence rate, 0.5 event per 100 person-years [95% CI, 0.06 to 1.83 events per 100 person-years]) compared with no cases among the 322 patients assigned to azithromycin (CI, 0 to 0.92 events per 100 person-years), resulting in a treatment difference of 0.5 event per 100 person-years (CI, -0.20 to 1.21 events per 100 person-years) for placebo versus azithromycin. Both cases were atypical in that M. avium complex was localized to the vertebral spine. Patients receiving azithromycin were more likely than those receiving placebo to discontinue treatment with the study drug permanently because of adverse events (8% vs. 2%; hazard ratio, 0.24 [CI, 0.10 to 0.57]).

CONCLUSIONS

Prophylaxis against Mycobacterium avium complex can safely be withdrawn or withheld in adults with HIV infection who experience increases in CD4(+) cell count while receiving antiretroviral therapy.

Discontinuation of prophylaxis against Mycobacterium avium complex disease in HIV-infected patients who have a response to antiretroviral therapy. Terry Beirn Community Programs for Clinical Research on AIDS

BACKGROUND

Several agents are effective in preventing Mycobacterium avium complex disease in patients with advanced human immunodeficiency virus (HIV) infection. However, there is uncertainty about whether prophylaxis should be continued in patients whose CD4+ cell counts have increased substantially with antiviral therapy.

METHODS

We conducted a multicenter, double-blind, randomized trial of treatment with azithromycin (1200 mg weekly) as compared with placebo in HIV-infected patients whose CD4+ cell counts had increased from less than 50 to more than 100 per cubic millimeter in response to antiretroviral therapy. The primary end point was M. avium complex disease or bacterial pneumonia.

RESULTS

A total of 520 patients entered the study; the median CD4+ cell count at entry was 230 per cubic millimeter. In 48 percent of the patients, the HIV RNA value was below the level of quantification. The median prior nadir CD4+ cell count was 23 per cubic millimeter, and 65 percent of the patients had had an acquired immunodeficiency syndrome-defining illness. During follow-up over a median period of 12 months, there were no episodes of confirmed M. avium complex disease in either group (95 percent confidence interval for the rate of disease in each group, 0 to 1.5 episodes per 100 person-years). Three patients in the azithromycin group (1.2 percent) and five in the placebo group (1.9 percent) had bacterial pneumonia (relative risk in the azithromycin group, 0.60; 95 percent confidence interval, 0.14 to 2.50; P=0.48). Neither the rate of progression of HIV disease nor the mortality rate differed significantly between the two groups. Adverse effects led to discontinuation of the study drug in 19 patients assigned to receive azithromycin (7.4 percent) and in 3 assigned to receive placebo (1.1 percent; relative risk, 6.6; P=0.002).

CONCLUSIONS

Azithromycin prophylaxis can safely be withheld in HIV-infected patients whose CD4+ cell counts have increased to more than 100 cells per cubic millimeter in response to antiretroviral therapy.

Clarithromycin or rifabutin alone or in combination for primary prophylaxis of Mycobacterium avium complex disease in patients with AIDS: A randomized, double-blind, placebo-controlled trial. The AIDS Clinical Trials Group 196/Terry Beirn Community Programs for Clinical Research on AIDS 009 Protocol Team

The efficacy and safety of clarithromycin and rifabutin alone and in combination for prevention of Mycobacterium avium complex (MAC) disease were compared in 1178 patients with AIDS who had < or =100 CD4 T cells/microL in a randomized, double-blind, placebo-controlled trial. MAC disease occurred in 9%, 15%, and 7% of those randomized to clarithromycin or rifabutin alone or in combination, respectively; time-adjusted event rates per 100 patient-years (95% confidence interval [CI]) were 6.3 (4.2-8.3), 10.5 (7.8-13.2), and 4. 7 (2.9-6.5). Risk of MAC disease was reduced by 44% with clarithromycin (risk ratio [RR], 0.56; 95% CI, 0.37-0.84; P=.005) and by 57% with combination therapy (RR, 0.43; 95% CI, 0.27-0.69; P=. 0003), versus rifabutin. Combination therapy was not more effective than clarithromycin (RR, 0.79; 95% CI, 0.48-1.31; P=.36). Of those in whom clarithromycin or combination therapy failed, 29% and 27% of MAC isolates, respectively, were resistant to clarithromycin. There were no survival differences. Clarithromycin and combination therapy were more effective than rifabutin for prevention of MAC disease, but combination therapy was associated with more adverse effects (31%; P<.001).

Rifampin and pyrazinamide vs isoniazid for prevention of tuberculosis in HIV-infected persons: an international randomized trial. Terry Beirn Community Programs for Clinical Research on AIDS, the Adult AIDS Clinical Trials Group, the Pan American Health Organization, and the Centers for Disease Control and Prevention Study Group

CONTEXT

Because of problems with adherence, toxicity, and increasing resistance associated with 6- to 12-month isoniazid regimens, an alternative short-course tuberculosis preventive regimen is needed.

OBJECTIVE

To compare a 2-month regimen of daily rifampin and pyrazinamide with a 12-month regimen of daily isoniazid in preventing tuberculosis in persons with human immunodeficiency virus (HIV) infection.

DESIGN

Randomized, open-label controlled trial conducted from September 1991 to May 1996, with follow-up through October 1997.

SETTING

Outpatient clinics in the United States, Mexico, Haiti, and Brazil.

PARTICIPANTS

A total of 1583 HIV-positive persons aged 13 years or older with a positive tuberculin skin test result.

INTERVENTIONS

Patients were randomized to isoniazid, 300 mg/d, with pyridoxine hydrochloride for 12 months (n = 792) or rifampin, 600 mg/d, and pyrazinamide, 20 mg/kg per day, for 2 months (n = 791).

MAIN OUTCOME MEASURES

The primary end point was culture-confirmed tuberculosis; secondary end points were proven or probable tuberculosis, adverse events, and death, compared by treatment group.

RESULTS

Of patients assigned to rifampin and pyrazinamide, 80% completed the regimen compared with 69% assigned to isoniazid (P<.001). After a mean follow-up of 37 months, 19 patients (2.4%) assigned to rifampin and pyrazinamide and 26 (3.3%) assigned to isoniazid developed confirmed tuberculosis at rates of 0.8 and 1.1 per 100 person-years, respectively (risk ratio, 0.72 [95% confidence interval, 0.40-1.31]; P = .28). In multivariate analysis, there were no significant differences in rates for confirmed or probable tuberculosis (P = .83), HIV progression and/or death (P = .09), or overall adverse events (P = .27), although drug discontinuation was slightly higher in the rifampin and pyrazinamide group (P = .01). Neither regimen appeared to lead to the development of drug-resistant tuberculosis.

CONCLUSIONS

Our data suggest that for preventing tuberculosis in HIV-infected patients, a daily 2-month regimen of rifampin and pyrazinamide is similar in safety and efficacy to a daily 12-month regimen of isoniazid. This shorter regimen offers practical advantages to both patients and tuberculosis control programs.

[Effect of dapsone on survival in HIV infected patients: a meta- analysis of finished trials]

BACKGROUND

The aim of the study was to estimate the effect of dapsone on survival in HIVinfected patients.

METHOD

The method was a metaanalysis. Data searches used MEDLINE, AIDS TRIALS, and AIDS DRUGS databases from 1983 to January 1996, clinical trials registries of appropriate collaborative research groups, abstract books of International Conferences on AIDS and infectious diseases between 1988 and 1996, references listed within selected articles and active experts in HIV infection. Were considered as eligible: randomized clinical trials, conducted in adults, with one arm evaluating dapsone as prophylactic agent for Pneumocystis Carinii Pneumonia (PCP). Each primary investigator was asked to provide the most recent aggregated study data by completing a standardized questionnaire and to provide files of individual patient data whenever possible.

RESULTS

Overall, 17 trials (4343 patients) were eligible for the metaanalysis. The analysis of all available aggregated data included 16 trials (4267 patients) and showed no deleterious effect of dapsone on survival: OR=1.11, 95% Confidence Interval (CI)=0.961.29. There was no evidence of heterogeneity among studies (p=0.50). The analysis of individual data included 10 trials (3115 patients) (OR for aggregated data from those trials=1.10, CI=0. 931.29) and confirmed the absence of deleterious effect of dapsone on survival: stratified Hazard Ratio=1.12, CI=0.991.27 (logrank test: p=0.08). In this subsample, there was evidence of a deleterious effect of dapsone used as secondary prophylaxis. However, this result did not remain when the trial reporting the greatest negative effect of dapsone on survival was omitted.

CONCLUSION

Dapsone may be used safely as a primary prophylactic regimen for PCP or toxoplasmosis. However, no definitive recommendation can be made for the use of dapsone as secondary PCP prophylaxis.

A randomized trial of daily and thrice-weekly trimethoprim-sulfamethoxazole for the prevention of Pneumocystis carinii pneumonia in human immunodeficiency virus-infected persons. Terry Beirn Community Programs for Clinical Research on AIDS (CPCRA)

We enrolled 2,625 human immunodeficiency virus-infected patients into a randomized trial to assess the efficacy and tolerability of daily vs. thrice-weekly trimethoprim-sulfamethoxazole (160 mg/800 mg) for prophylaxis of Pneumocystis carinii pneumonia (PCP). The rate of PCP was 3.5 and 4.1 per 100 person-years in the daily and thrice-weekly groups, respectively, with a relative risk (RR) of 0.82 (95% confidence interval [CI], 0.61-1.09; P = .16) (RR of <1.0 favors daily trimethoprim-sulfamethoxazole). The RR for PCP determined by on-treatment analysis was 0.59 (P = .03). The RR for death was 0.91 (P = .12); for bacterial pneumonia, 0.82 (P = .06); and for combined PCP and bacterial pneumonia, 0.84 (P = .04). Discontinuation due to adverse events occurred more commonly in the daily trimethoprim-sulfamethoxazole group (RR, 2.14; 95% CI, 1.73-2.66; P < .001). Overall estimates for efficacy end points favored daily trimethoprim-sulfamethoxazole, although rates of intolerance were higher among patients receiving that dose. Daily trimethoprim-sulfamethoxazole may offer advantages as a first choice for PCP prophylaxis; thrice-weekly dosing is an appropriate option for patients intolerant of the daily dose.

Correlation of quantitative bone marrow and blood cultures in AIDS patients with disseminated Mycobacterium avium complex infection

The relationship between Mycobacterium avium complex (MAC) infection of blood and bone marrow was studied in human immunodeficiency virus-infected patients before and during treatment. Quantitative cultures were obtained at baseline from 17 persons with newly detected MAC bacteremia. Serial blood cultures were obtained, and a second bone marrow sample was obtained at 4 or 8 weeks. At baseline, the median MAC load in bone marrow core samples was 3 log10 higher than in blood. Bone marrow MAC loads ranged widely (866-847,315 cfu/g), and no significant correlation was found between MAC load in blood and that in bone marrow core samples. MAC loads in bilateral bone marrow biopsy samples from 7 subjects were highly correlated. MAC loads declined in blood and bone marrow at similar rates during therapy, but blood was sterilized before bone marrow. Length of survival was inversely associated with initial bone marrow core MAC load but not with blood MAC load. Initiation of treatment when tissue MAC load is low may increase the likelihood of favorable clinical outcome.

A prospective randomized trial of four three-drug regimens in the treatment of disseminated Mycobacterium avium complex disease in AIDS patients: excess mortality associated with high-dose clarithromycin. Terry Beirn Community Programs for Clinical Research on AIDS

The optimal regimen for treatment of Mycobacterium avium complex (MAC) disease has not been established. Eighty-five AIDS patients with disseminated MAC disease were randomized to receive a three-drug regimen of clarithromycin, rifabutin or clofazimine, and ethambutol. Two dosages of clarithromycin, 500 or 1,000 mg twice daily (b.i.d.), were compared. The Data and Safety Monitoring Board recommended discontinuation of the clarithromycin dosage comparison and continuation of the rifabutin vs. clofazimine comparison. After a mean follow-up of 4.5 months, 10 (22%) of 45 patients receiving clarithromycin at 500 mg b.i.d. had died (70 deaths per 100 person-years) compared with 17 (43%) of 40 patients receiving clarithromycin at 1,000 mg b.i.d. (158 deaths per 100 person-years) (relative risk, 2.43; 95% confidence interval, 1.11-5.34; P = .02). After 10.4 months, 20 (49%) of 41 patients receiving rifabutin had died (81 deaths per 100 person-years) compared with 23 (52%) of 44 patients receiving clofazimine (94 deaths per 100 person-years) (relative risk, 1.20; 95% confidence interval, 0.65-2.19; P = .56). Bacteriologic outcomes were similar among treatment groups. In treating MAC disease in AIDS patients, the maximum dose of clarithromycin should be 500 mg b.i.d.

Escalating multiple-dose safety and tolerance study of oral WR 6026 in HIV-infected subjects: AIDS clinical trials group 173

WR 6026 is an 8-aminoquinoline with activity against Pneumocystis carinii in vitro and in an animal model of P. carinii pneumonia that has predicted the clinical utility of related compounds. This study was conducted to assess the safety and tolerance of WR 6026 given once daily for 21 days to HIV-infected subjects with CD4 counts <500 cells/microl. This double-blind, placebo-controlled study employed WR 6026 doses starting at 30 mg once daily and increasing to 60, 90, 120, or 150 mg once daily. Weekly visits for clinical and laboratory monitoring were conducted. Forty-nine study subjects, including 25 subjects with CD4 counts <200 cells/microl and 12 subjects with CD4 counts <100 cells/microl, entered the study. The maximum tolerated dose was 120 mg/day. Dose-limiting methemoglobinemia (>20%) was seen in 3 of 6 study subjects who received 150 mg/day for > or =19 days. Methemoglobin level was correlated with peak plasma WR 6026 concentrations. Three other study subjects developed skin rashes that may have been drug-related, and two developed asymptomatic serum triglyceride levels >1000 mg/dl. We conclude that WR 6026 is well tolerated at doses up to 120 mg/day for 21 days in HIV-infected volunteers including those with CD4 counts <200 cells/microl. Methemoglobinemia appears to be the primary dose-limiting toxicity.

A comparison of itraconazole versus fluconazole as maintenance therapy for AIDS-associated cryptococcal meningitis. National Institute of Allergy and Infectious Diseases Mycoses Study Group

This study was designed to compare the effectiveness of fluconazole vs. itraconazole as maintenance therapy for AIDS-associated cryptococcal meningitis. HIV-infected patients who had been successfully treated (achieved negative culture of CSF) for a first episode of cryptococcal meningitis were randomized to receive fluconazole or itraconazole, both at 200 mg/d, for 12 months. The study was stopped prematurely on the recommendation of an independent Data Safety and Monitoring Board. At the time, 13 (23%) of 57 itraconazole recipients had experienced culture-positive relapse, compared with 2 relapses (4%) noted among 51 fluconazole recipients (P = .006). The factor best associated with relapse was the patient having not received flucytosine during the initial 2 weeks of primary treatment for cryptococcal disease (relative risk = 5.88; 95% confidence interval, 1.27-27.14; P = .04). Fluconazole remains the treatment of choice for maintenance therapy for AIDS-associated cryptococcal disease. Flucytosine may contribute to the prevention of relapse if used during the first 2 weeks of primary therapy.

A phase II/III trial of antimicrobial therapy with or without amikacin in the treatment of disseminated Mycobacterium avium infection in HIV-infected individuals. AIDS Clinical Trials Group Protocol 135 Study Team

OBJECTIVE

To determine the clinical and microbiologic benefit of adding amikacin to a four-drug oral regimen for treatment of disseminated Mycobacterium avium infection in HIV-infected patients.

DESIGN

A randomized, open-labeled, comparative trial.

SETTING

Outpatient clinics.

PATIENTS

Seventy-four patients with HIV and symptomatic bacteremic M. avium infection.

INTERVENTIONS

Rifampin 10 mg/kg daily, ciprofloxacin 500 mg twice daily, clofazimine 100 mg every day, and ethambutol 15 mg/kg orally daily for 24 weeks, with or without amikacin 10 mg/kg intravenously or intramuscularly 5 days weekly for the first 4 weeks.

MAIN OUTCOME MEASURE

Clinical and microbiologic response at 4 weeks; quantitative level of bacteremia with M. avium.

RESULTS

No difference in clinical response was noted with the addition of amikacin to the four-drug oral regimen, and only 25% in either group had a complete or partial response at 4 weeks. A comparable quantitative decrease in bacteremia was noted in both treatment groups, with 16% of patients being culture-negative at 4 weeks and 38% at 12 weeks. Toxicities were mainly gastrointestinal. Amikacin was well tolerated. Median survival was 30 weeks in both groups.

CONCLUSIONS

The addition of amikacin to a four-drug oral regimen of rifampin, ciprofloxacin, clofazimine, and ethambutol did not provide clinical or microbiologic benefit.

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.

Comparison of ketorolac and diclofenac in the treatment of renal colic

OBJECTIVE

To compare the efficacy and adverse effects of ketorolac and diclofenac in the treatment of renal colic.

METHODS

In a double-blind, randomized clinical trial, 57 patients admitted to the emergency room for renal colic, received either 30 mg of ketorolac or 75 mg of diclofenac i.m. (intramuscularly). Evaluations were performed at 1, 2 h and 6 h after treatment. Pain was assessed by a four-point verbal rating scale (VRS) and a visual analogue scale (VAS). Only patients with at least moderate pain according to the VRS were included. Seventy-five milligrams of pethidine i.m. was given as rescue medicine, if insufficient analgesia was achieved. The adverse effects recorded were sedation, nausea and vomiting.

RESULTS

There was no significant difference between ketorolac and diclofenac, with respect to pain level over time, the number of patients requiring rescue medicine, or the level of adverse effects.

CONCLUSION

Ketorolac and diclofenac are equally effective in the treatment of renal colic.

The effect of increasing gastric pH upon the bioavailability of orally-administered foscarnet

For systemic use, the anti-cytomegalovirus (CMV) agent foscarnet must be given intravenously because oral administration results in unmeasurable or barely measurable plasma levels. At low pH, foscarnet decomposes via an acid-catalyzed decarboxylation; therefore, poor oral bioavailability might be due to decomposition of foscarnet in gastric acid. We evaluated whether increasing gastric pH with ranitidine would enhance the absorption of oral foscarnet in six asymptomatic HIV-infected individuals. Each volunteer received two oral 4000-mg (60 mg/kg) doses of foscarnet, preceded intravenously by a 20-min infusion of either ranitidine 50 mg in D5W or D5W alone in a randomized, double-blind, cross-over study. Intragastric pH monitoring revealed that subjects had evidence of gastric acid production (pH < 2.0) prior to administration of ranitidine and increased gastric pH (pH > 6.0) following ranitidine administration. Most foscarnet plasma levels were below the assay limit of detection (33 microM) with only 4/30 levels detectable after D5W and 8/30 after ranitidine. Urinary recovery of foscarnet increased after ranitidine pretreatment. A mean recovery of 9.9% of the drug was realized in the urine in 24 h following ranitidine pretreatment compared to 6.2% of the dose after D5W pretreatment (P < 0.03). We estimate that 9.9% recovery in the urine in 24 h is equivalent to absorption of 17.1% of the oral dose. In spite of the enhanced bioavailability associated with ranitidine pretreatment, the degree of absorption is still insufficient to achieve effective plasma concentrations for the treatment of CMV or acyclovir-resistant herpes viruses. We conclude that gastric acidity is a determinant of foscarnet absorption, albeit not a major one. Oral foscarnet is unlikely to be clinically useful even if administered in the setting of increased gastric pH.

Intention-to-treat vs. on-treatment analyses of clinical trial data: experience from a study of pyrimethamine in the primary prophylaxis of toxoplasmosis in HIV-infected patients. ANRS 005/ACTG 154 Trial Group

Randomized clinical trials analyzed by the intent-to-treat approach provide unbiased comparisons among treatment groups. To avoid dilution of treatment effect, many people also perform an analysis by treatment actually received, although this method may introduce bias into the results. This paper presents several approaches used for analyzing data of a recent trial and the difficulties encountered in interpreting the results of each approach. The ANRS 005/ACTG 154 Study was a double-blind, placebo-controlled, randomized, international (French, U.S., and Spanish) multicenter trial designed to assess the effectiveness of pyrimethamine for the primary prophylaxis of cerebral toxoplasmosis (CT) in HIV-infected patients with advanced immunodeficiency. In the intention-to-treat analysis, the cumulative probability of CT at 1 year did not differ significantly between the pyrimethamine arm (11.9%) and the placebo arm (13.1%), Hazard Ratio (HR) = 0.94 (95% Confidence Interval (CI) = 0.62-1.42), whereas an on-treatment analysis resulted in a significant difference: 4.2% in the pyrimethamine arm and 12.4% in the placebo arm, HR = 0.44 (95% CI = 0.24-0.80). The data showed a significant interaction between compliance and treatment outcome; and side effects were more frequently cited as reasons for compliance violations in the pyrimethamine group. Several different analytic approaches (censoring data at the time patients discontinued the study medication only for selected reasons) failed to explain the disparity between the estimation of effect of pyrimethamine by the intention-to-treat and on-treatment analyses. This experience led us to believe that comparing the results of both analyses was the best method to convince clinicians that intention-to-treat was the only interpretable analysis. We were concerned that even if pyrimethamine had a beneficial effect, it was very difficult (1) to quantify and (2) to apply to clinical practice unless one could predict the occurrence of study drug discontinuation for each patient at the time of treatment assignment. Although exploratory analyses may yield clinically relevant information and useful clarifications in the evaluation of treatments, intention-to-treat remains the only interpretable analysis of clinical trials.

Evaluation of an intensive intermittent-induction regimen and duration of short-course treatment for human immunodeficiency virus-related pulmonary tuberculosis. Terry Beirn Community Programs for Clinical Research on AIDS (CPCRA) and the AIDS Clinical Trials Group (ACTG)

This study examined whether adding levofloxacin to a standard four-drug regimen improved the 8-week culture response and compared effectiveness of 9 versus 6 months of intermittent therapy for human immunodeficiency virus-related pansusceptible pulmonary tuberculosis. Patients were randomized to receive either four or five drugs, the fifth being levofloxacin. Patients who completed induction therapy were randomized to complete 9 versus 6 months of intermittent therapy with isoniazid and rifampin. In the randomized induction phase, 97.3% of patients in the four-drug group and 95.8% in the five-drug group had sputum culture conversion at 8 weeks (P = 1.00). In the continuation phase, one patient (2%) assigned to 9 months and two patients (3.9%) assigned to 6 months of therapy had treatment failure/relapse (P = 1.00). In conclusion, this study showed that levofloxacin added no benefit to a highly effective, largely intermittent, four-drug induction regimen. Both 9 and 6 months of intermittent therapy were associated with low treatment failure/relapse rates.

Tolerance and pharmacokinetic interactions of rifabutin and clarithromycin in human immunodeficiency virus-infected volunteers

This study evaluated the tolerance and potential pharmacokinetic interactions between clarithromycin (500 mg every 12 h) and rifabutin (300 mg daily) in clinically stable human immunodeficiency virus-infected volunteers with CD4 counts of <200 cells/mm3. Thirty-four subjects were randomized equally to either regimen A or regimen B. On days 1 to 14, subjects assigned to regimen A received clarithromycin and subjects assigned to regimen B received rifabutin, and then both groups received both drugs on days 15 to 42. Of the 14 regimen A and the 15 regimen B subjects who started combination therapy, 1 subject in each group prematurely discontinued therapy due to toxicity, but 19 of 29 subjects reported nausea, vomiting, and/or diarrhea. Pharmacokinetic analysis included data for 11 regimen A and 14 regimen B subjects. Steady-state pharmacokinetic parameters for single-agent therapy (day 14) and combination therapy (day 42) were compared. Regimen A resulted in a mean decrease of 44% (P = 0.003) in the clarithromycin area under the plasma concentration-time curve (AUC), while there was a mean increase of 57% (P = 0.004) in the AUC of the clarithromycin metabolite 14-OH-clarithromycin. Regimen B resulted in a mean increase of 99% (P = 0.001) in the rifabutin AUC and a mean increase of 375% (P < 0.001) in the AUC of the rifabutin metabolite 25-O-desacetyl-rifabutin. The usefulness of this combination for prophylaxis of Mycobacterium avium infections is limited by frequent gastrointestinal adverse events. Coadministration of clarithromycin and rifabutin results in significant bidirectional pharmacokinetic interactions. The resulting increase in rifabutin levels may explain the increased frequency of uveitis observed with concomitant use of these drugs.

Itraconazole maintenance treatment for histoplasmosis in AIDS: a prospective, multicenter trial

PURPOSE

To study the efficacy and safety of maintenance treatment with itraconazole for disseminated histoplasmosis in patients with AIDS.

PATIENTS AND METHODS

This was a prospective, multicenter, open-label study conducted at university-based hospitals participating in the AIDS Clinical Trial Group (ACTG). Forty-six AIDS patients with mild to moderate disseminated histoplasmosis who had successfully completed 12 weeks of induction treatment with itraconazole were treated with itraconazole, 200 mg once daily (42 patients) or 400 mg once daily (4 patients). Patients were followed at monthly intervals with clinical and laboratory assessment for relapse or toxicity. Primary outcome measures were relapse of histoplasmosis and survival. Secondary outcome measures included drug-limiting toxicity and changes in serum and urine Histoplasma polysaccharide antigen (HPA) levels.

RESULTS

Two patients relapsed during a median follow-up period of 87 weeks. The 1-year relapse-free rate was estimated to be 95.3% (95% CI, 85.3%-99.7%). One relapse may have been related to poor adherence to treatment and the second to concurrent administration of rifampin. From the start of maintenance treatment, the estimated 1-year survival rate was 73.0% (95% CI, 67.5%-77.9%). Five patients discontinued treatment because of suspected drug toxicity, three of whom had possible or probable hepatotoxicity. Median serum and urine HPA levels declined significantly during treatment. The only patient in whom antigen levels rose >2 U developed clinical relapse 1 week later; antigen levels were unavailable in the other relapsing patient.

CONCLUSIONS

Itraconazole, 200 mg daily, is effective in preventing relapse of disseminated histoplasmosis in patients with AIDS. It is generally well tolerated, but clinicians should be alert for drug interactions and possible hepatotoxicity.

Susceptibility to levofloxacin of Myocobacterium tuberculosis isolates from patients with HIV-related tuberculosis and characterization of a strain with levofloxacin monoresistance. Community Programs for Clinical Research on AIDS 019 and the AIDS Clinical Trials Group 222 Protocol Team

OBJECTIVE

To characterize the susceptibility to levofloxacin of clinical isolates of Mycobacterium tuberculosis (MTB) obtained from patients with HIV-related tuberculosis and to characterize the molecular genetics of levofloxacin resistance.

DESIGN AND METHODS

Isolates from culture-positive patients in a United States multicenter trial of HIV-related TB were tested for susceptibility to levofloxacin by minimum inhibitory concentration (MIC) determinations in Bactec 7H12 broth. Automated sequencing of the resistance determining region of gyrA was performed.

RESULTS

Of the 135 baseline MTB isolates tested, 134 (99%; 95% exact binomial confidence interval, 95.9-99.9%) were susceptible to levofloxacin with an MIC < or = 1.0 microg/ml. We identified a previously unrecognized mis-sense mutation occurring at codon 88 of gyrA in a levofloxacin mono-resistant MTB isolate obtained from a patient with AIDS who had received ofloxacin for 8 months prior to the diagnosis of tuberculosis.

CONCLUSIONS

Clinical MTB isolates from HIV-infected patients were generally susceptible to levofloxacin. However, the identification of a clinical isolate with mono-resistance to levofloxacin highlights the need for circumspection in the use of fluoroquinolones in the setting of potential HIV-related tuberculosis and for monitoring of rates of resistance of MTB isolates to fluoroquinolones.

Early bactericidal activity of isoniazid in pulmonary tuberculosis. Optimization of methodology. The DATRI 008 Study Group

Early bactericidal activity (EBA) of antituberculosis drugs is the rate of decrease in the concentration of tubercle bacilli sputum during the initial days of therapy. The study reported here was designed to optimize the methodology for obtaining precise EBA measurements. The study compared the results with two versus five treatment days; overnight sputum collections with early morning collections; and quantitative smears for acid-fast bacilli (AFB) with quantitative cultures. Isoniazid (INH) was used as a model drug. Among 28 smear-positive patients enrolled in the study in five cities in the United States, 16 were evaluable (INH-susceptible tuberculosis [TB] and adequate sputum collections). The mean baseline bacterial load was 6.69 log10 cfu/ml (SE = 0.24). Quantitative culture of 10- or 12-h sputum collections obtained on two baseline days and treatment Day 5 was the optimal method for EBA measurement. The mean 5-d EBA was 0.21 log10 cfu/ml/d (SE = 0.03; p < 0.001) and the EBA appeared to be constant during the first five treatment days. On the basis of these data, multiarm studies of investigational drugs will require 25 evaluable subjects per arm to detect (80% power and two-tailed alpha of 0.05) an EBA at least 50% as large as the EBA of INH. In countries with a low incidence of TB, the usefulness of this methodology for rapidly assessing new antituberculosis agents may be limited by the relatively large number of subjects required to compare EBA values across treatment arms.

Treatment of histoplasmosis with fluconazole in patients with acquired immunodeficiency syndrome. National Institute of Allergy and Infectious Diseases Acquired Immunodeficiency Syndrome Clinical Trials Group and Mycoses Study Group

PURPOSE

This study assesses the efficacy and safety of fluconazole therapy in patients with acquired immunodeficiency syndrome (AIDS) and mild to moderately severe manifestations of disseminated histoplasmosis.

PATIENTS AND METHODS

This was a multicenter, open-label, nonrandomized prospective trial. All patients had AIDS and disseminated histoplasmosis. Patients were treated with 1,200 mg of fluconazole given by mouth once on the first day, then 600 mg once daily for 8 weeks, and those patients who improved clinically were then assigned fluconazole maintenance therapy 200 mg once daily for at least 1 year. Interim analysis revealed a high failure rate (10 of 20, 50%), causing revision of the protocol to increase the fluconazole dose to 1,600 mg given once on the first day, then 800 mg once daily, and the duration to 12 weeks for induction therapy and then 400 mg daily for 1 year for maintenance therapy.

MEASUREMENTS AND MAIN RESULTS

Thirty-six of 49 patients (74%; 95% confidence interval [CI]: 59% to 85%) with mild to moderately severe clinical manifestations who entered into the revised study responded to 800 mg of fluconazole daily for 12 weeks as induction therapy. Of the seven patients who failed induction therapy because of progression of histoplasmosis, one died of the infection. Of 36 patients who entered into the maintenance phase of the study receiving 400 mg of fluconazole daily for 1 year, 11 (30.5%) relapsed, including one who died (2.8%). Two of the 49 patients (4.1%) were removed because of grade 4 adverse events, alkaline phosphatase elevation for one and aspartate aminotransferase elevation in the other. The relapse-free rate at 1 year was 53% (95% CI: 32% to 89%), prompting closure of the study.

CONCLUSIONS

Fluconazole 800 mg daily is a safe and moderately effective induction therapy for mild or moderately severe disseminated histoplasmosis in patients with AIDS. On the basis of historic comparison, fluconazole 400 mg daily is less effective than itraconazole 200 to 400 mg daily or amphotericin B 50 mg given weekly as maintenance therapy to prevent relapse.

Variation of chest radiographic patterns in pulmonary tuberculosis by degree of human immunodeficiency virus-related immunosuppression. The Terry Beirn Community Programs for Clinical Research on AIDS (CPCRA). The AIDS Clinical Trials Group (ACTG)

Our aim was to evaluate the effect of human immunodeficiency virus (HIV) disease stage on chest radiographic (CXR) findings among patients with HIV-related pulmonary tuberculosis (TB). Data are from a prospective multicenter treatment trial for HIV-related TB. Baseline CXR findings and CD4+ lymphocyte counts were compared among patients with HIV-related TB. Data from published studies describing CXR findings in HIV-infected patients were reviewed and a pooled-data analysis was conducted. Of 135 patients with culture-confirmed HIV-related TB, 128 had both CXR and CD4+ lymphocyte data. CD4+ lymphocyte counts of < 200/mm3 (n = 98) were significantly associated with hilar/mediastinal adenopathy on CXR (30%, vs. 7% with counts > or = 200/mm3; P = .01); counts of > or = 200/mm3 (n = 30) more frequently were associated with cavitation (20% vs. 7%; P = .08). Analyses of these results, pooled with other published data, confirmed these findings. This study demonstrates associations of certain CXR findings with HIV disease stage. Knowledge of the degree of immunosuppression is important when evaluating CXR findings in HIV-infected patients.

A controlled trial of isoniazid in persons with anergy and human immunodeficiency virus infection who are at high risk for tuberculosis. Terry Beirn Community Programs for Clinical Research on AIDS

BACKGROUND

Patients with human immunodeficiency virus (HIV) infection and latent tuberculosis are at substantial risk for the development of active tuberculosis. As a public health measure, prophylactic treatment with isoniazid has been suggested for HIV-infected persons who have anergy and are in groups with a high prevalence of tuberculosis.

METHODS

We conducted a multicenter, randomized, double-blind, placebo-controlled trial of six months of prophylactic isoniazid treatment in HIV-infected patients with anergy who have risk factors for tuberculosis infection. The primary end point was culture-confirmed tuberculosis.

RESULTS

The study was conducted from November 1991 through June 1996. Over 90 percent of the patients had two or more risk factors for tuberculosis infection, and nearly 75 percent of patients were from greater New York City. After a mean follow-up of 33 months, tuberculosis was diagnosed in only 6 of 257 patients in the placebo group and 3 of 260 patients in the isoniazid group (risk ratio, 0.48; 95 percent confidence interval, 0.12 to 1.91; P=0.30). There were no significant differences between the two groups with regard to death, death or the progression of HIV disease, or adverse events.

CONCLUSIONS

Even in HIV-infected patients with anergy and multiple risk factors for latent tuberculosis infection, the rate of development of active tuberculosis is low. This finding does not support the use of isoniazid prophylaxis in high-risk patients with HIV infection and anergy unless they have been exposed to active tuberculosis.

Survival after AIDS-defining events in patients with < 200 lymphocytes CD4+ x 10(6)/L who are toxoplasmosis antibody positive. ANRS 005/ACTG 154 Trial Group

The objective of this study was to assess whether patients with CD4+ cell counts <200 x 10(6)/L have a decreased survival after the occurrence of any AIDS-defining event; 187 patients from the placebo arm of a clinical trial of toxoplasmosis prophylaxis (ANRS005-ACTG154) were included. For this analysis, patients were HIV infected without any AIDS-defining event, had a CD4+ lymphocyte count < 200 x 10(6)/L, had a positive serology for Toxoplasma gondii, and had no severe liver, renal, or hematologic abnormalities. We used proportional hazards regression to study the relationships between baseline variables. AIDS-defining events as time-dependent variables, and survival. The risk of dying was increased by 1.9 for a 10-year increase in age and by 1.3 when CD4+ decreased by 50 x 10(6)/L; after the occurrence of a pneumocystosis, a cytomegalovirus infection, or a toxoplasmosis, the risk of dying was multiplied, respectively, by 10.9 (3.0-40.2), 10.0 (2.8-35.4), and 10.0 (4.5-22.2). None of the other AIDS-defining events was associated with an increased risk of dying, but the power to detect such an association was limited. We conclude that the occurrence of pneumocystosis, cytomegalovirus infection, or toxoplasmosis; age; and CD4+ cell count are important determinants of survival for HIV1-infected patients with CD4+ counts < 200 x 10(6)/L who are toxoplasmosis antibody positive.

Increased risk of toxoplasmic encephalitis in human immunodeficiency virus-infected patients with pyrimethamine-related rash. ANRS 005-ACTG 154 Trial Group. Agence Nationale de Recherche sur le SIDA (ANRS-INSERM) and the NIAID-AIDS Clinical Trials Group

Although drug-induced rash is frequent in human immunodeficiency virus (HIV)-infected patients, rash due to pyrimethamine has not been described previously. In a randomized, double-blind, placebo-controlled study of pyrimethamine as primary prophylaxis for toxoplasmic encephalitis, the incidence of rash (per hundred patient-years) was 8.1 in the pyrimethamine group versus 1.5 in the placebo group (P < .0002). The 1-year incidence of toxoplasmic encephalitis after occurrence of rash was 37%, as compared with 9.6% in the pyrimethamine group without rash, with a 3.7 times higher risk for patients with pyrimethamine-induced rash (P = .001); the incidence was 13% in the placebo group. At the time of toxoplasmic encephalitis, pyrimethamine was successfully readministered to 80% of patients who discontinued it because of rash. Thus, pyrimethamine, when used for prophylaxis, does induce rash in HIV-infected patients. These patients are at higher risk for toxoplasmic encephalitis and should be carefully monitored for it.

Predictive value of Toxoplasma gondii antibody titres on the occurrence of toxoplasmic encephalitis in HIV-infected patients. ANRS 005/ACTG 154 Trial Group

OBJECTIVE

To study the predictive value of anti-Toxoplasma gondii antibody titres for the occurrence of toxoplasmic encephalitis (TE) in HIV-infected patients.

METHODS

Data from the placebo arm of a trial of primary prophylaxis for TE (ANRS 005/ACTG 154) were analysed. Patients included had CD4+ cell counts < 200 x 10(6)/l and a positive Toxoplasma serology. Immunoglobulin (Ig) G and IgM Toxoplasma antibody titres at entry were retrospectively determined by enzyme-linked immunosorbent assay and agglutination on serum samples in a single laboratory. Incidence of TE was estimated by Kaplan-Meier method and a Cox model was used to study the predictive value of antibody titres, adjusted for other covariates.

RESULTS

All 164 patients studied were positive for IgG antibodies and one had IgM antibodies. After a mean follow-up of 16 months, 31 cases of TE were documented. One-year incidence of TE was significantly higher in patients with IgG titres > or = 150 IU/ml (23.7%) than in patients with titres < 150 IU/ml (7.7%; relative risk, 3.1; P < 0.003). IgG titres remained significantly associated with the occurrence of TE (relative risk, 3.3; P < 0.005) in the Cox model. Predictive value of IgG titres did not differ according to baseline CD4+ cell counts.

CONCLUSIONS

In patients with CD4+ cell counts < 200 x 10(6)/l, IgG anti-Toxoplasma antibody titre is a prognostic factor of occurrence of TE, with a higher risk for titres > or = 150 IU/ml. This finding should reinforce the recommendation of specific prophylaxis in these patients.

Pyrimethamine pharmacokinetics in human immunodeficiency virus-positive patients seropositive for Toxoplasma gondii

Pyrimethamine pharmacokinetics were studied in 11 human immunodeficiency virus (HIV)-positive patients who were seropositive for exposure to Toxoplasma gondii and were taking zidovudine (AIDS Clinical Trials Group Protocol 102). Pyrimethamine was administered at 50 mg daily for 3 weeks to achieve steady state, and pharmacokinetic profiles were determined after administration of the last dose. Noncompartmental and compartmental analyses were performed. Population pharmacokinetic analysis assuming a one-compartment model yielded the following estimates: area under the 24-h concentration-time curve, 42.7 +/- 12.3 micrograms.h/ml; halflife, 139 +/- 34 h; clearance, 1.28 +/- 0.41 liters/h; volume of distribution, 246 +/- 641; and absorption rate constant, 1.5 +/- 1.3 liters/h. These values are similar to those seen in subjects without HIV infection. Pyrimethamine pharmacokinetics did not differ significantly in those subjects who were intravenous drug users. Adverse effects were noted in 73% of those initially enrolled in this study, leading to discontinuation for 38%. No association was noted between pyrimethamine levels and the incidence of adverse events. No significant differences were seen in zidovudine pharmacokinetic parameters obtained from studies performed before and during treatment with pyrimethamine. In summary, pyrimethamine exhibited pharmacokinetics in HIV-infected patients that were similar to those in non-HIV-infected subjects and it did not alter the pharmacokinetics of zidovudine in these patients.

Pyrimethamine for primary prophylaxis of toxoplasmic encephalitis in patients with human immunodeficiency virus infection: a double-blind, randomized trial. ANRS 005-ACTG 154 Group Members. Agence Nationale de Recherche sur le SIDA. AIDS Clinical Trial Group

Pyrimethamine (50 mg) with folinic acid (15 mg) given three times weekly was assessed as primary prophylaxis for toxoplasmic encephalitis (TE) in 554 human immunodeficiency virus-infected patients seropositive for Toxoplasma gondii and with < 200 CD4 cells/mm3. At 1 year, the incidence of TE was similar in pyrimethamine, 12%, and placebo, 13%, groups (relative risk [RR], 0.9; 95% confidence interval [CI], 0.6-1.4), and the survival rate was also similar, 85% and 80%, respectively (RR, 0.9; 95% CI, 0.7-1.2). Rash was the only adverse event that appeared significantly more frequently in the pyrimethamine arm (7% vs. 1%). In the on-treatment analysis, the incidence of TE was lower in the pyrimethamine arm, 4%, than in the placebo arm, 12% (P < .006). Thus, pyrimethamine cannot be recommended as a first-line regimen for primary prophylaxis of TE if the patient can take cotrimoxazole. However, it should be considered for patients who are intolerant to cotrimoxazole, especially in high-risk patients with < 100 CD4 cells/mm3.

Itraconazole treatment of disseminated histoplasmosis in patients with the acquired immunodeficiency syndrome. AIDS Clinical Trial Group

PURPOSE

Amphotericin B has been the treatment of choice for disseminated histoplasmosis in patients with acquired immunodeficiency syndrome (AIDS). Oral antifungal agents would be welcome alternatives to standard treatment of disseminated histoplasmosis in less severe cases. The purpose of this study was to assess the efficacy and safety of itraconazole therapy in patients with AIDS and disseminated histoplasmosis.

PATIENTS AND METHODS

This was a multicenter, open-label, nonrandomized prospective trial conducted in university hospitals of the AIDS Clinical Trial Group. All patients had AIDS and first episodes of disseminated histoplasmosis. Patients with central nervous system involvement or with severe clinical manifestations were excluded. Patients were treated with itraconazole BID by mouth 300 mg for 3 days and then 200 mg BID for 12 weeks. Resolution of clinical findings, clearance of positive cultures, and drug tolerance were the main outcome measurements. A secondary objective was effect of therapy on Histoplasma capsulatum var capsulatum antigen levels.

RESULTS

Of 59 evaluable patients, 50 (85%) responded to therapy. Five patients withdrew because of progressive infection, 1 died of a presumed pulmonary embolus within the first week of therapy without improvement, 2 withdrew because of toxicity, and 1 was lost to follow-up after week 2 of therapy. Patients with moderately severe clinical (fever > 39.5 degrees C or Karnofsky score < 60) or laboratory abnormalities (alkaline phosphatase > 5 times normal or albumin < 3 g/dL) at baseline tended to respond more poorly than did other patients. Resolution of complaints of fever and improvement in fatigue occurred after a median of 3 and 6 weeks, respectively, and weight gain after 2 weeks. Fungemia cleared after a median of 1 week. H capsulatum var capsulatum antigen cleared from the urine and serum at rates of 0.2 and 0.3 units per week, respectively.

CONCLUSIONS

Itraconazole is safe and effective induction therapy for mild disseminated histoplasmosis in patients with AIDS, offering an alternative to amphotericin B in such cases. Patients with moderately severe or severe histoplasmosis should first be treated with amphotericin B and then may be switched to itraconazole after achieving clinical improvement.

Primary prophylaxis with pyrimethamine for toxoplasmic encephalitis in patients with advanced human immunodeficiency virus disease: results of a randomized trial. Terry Beirn Community Programs for Clinical Research on AIDS

Pyrimethamine, 25 mg thrice weekly, was evaluated as primary prophylaxis for toxoplasmic encephalitis (TE) in a double-blind, randomized clinical trial in patients with human immunodeficiency virus (HIV) disease, absolute CD4 lymphocyte count of < 200/microL (or prior AIDS-defining opportunistic infection), and the presence of serum IgG to Toxoplasma gondii. Leucovorin was coadministered only for hematologic toxicity. There was a significantly higher death rate among patients receiving pyrimethamine (relative risk [RR], 2.5; 95% confidence interval [CI], 1.3-4.8; P = .006), even after adjusting for factors predictive of survival. The TE event rate was low in both treatment groups (not significant). Only 1 of 218 patients taking trimethoprim-sulfamethoxazole but 7 of 117 taking aerosolized pentamidine for prophylaxis against Pneumocystis carinii pneumonia developed TE (adjusted RR for the trimethoprim-sulfamethoxazole group, 0.16; 95% CI, 0.01-1.79; P = .14). Thus, for HIV-infected patients receiving trimethoprim-sulfamethoxazole, additional prophylaxis for TE appears unnecessary.

Toxoplasmic encephalitis in patients with the acquired immunodeficiency syndrome. Members of the ACTG 077p/ANRS 009 Study Team

BACKGROUND

In patients with the acquired immunodeficiency syndrome (AIDS), toxoplasmic encephalitis is usually a presumptive diagnosis based on the clinical manifestations, a positive antitoxoplasma-antibody titer, and characteristic neuroradiologic abnormalities. A response to specific therapy helps to confirm the diagnosis, but it is unclear how rapid the response should be. We studied the course of patients treated for acute toxoplasmic encephalitis and evaluated objective clinical criteria for this empirical diagnosis.

METHODS

A quantifiable neurologic assessment was used prospectively to evaluate the clinical outcome of patients with AIDS and toxoplasmic encephalitis who were treated with oral clindamycin (600 mg four times a day) and pyrimethamine (75 mg every day) for six weeks.

RESULTS

Thirty-five of 49 patients (71 percent) responded to therapy, and 30 of these (86 percent) had improvement by day 7. Thirty-two of those with a response (91 percent) improved with respect to at least half of their base-line abnormalities by day 14. Improvement in neurologic abnormalities within 7 to 14 days after the start of therapy was strongly associated with the neurologic response at 6 weeks. The four patients in whom treatment failed and the two patients with lymphoma had progressing neurologic abnormalities or new abnormalities during the first 12 days of therapy. Nonlocalizing abnormalities (headache and seizure) improved regardless of the clinical outcome.

CONCLUSIONS

Oral clindamycin and pyrimethamine are an effective treatment for toxoplasmic encephalitis. Patients who have early neurologic deterioration despite treatment or who do not improve neurologically after 10 to 14 days of appropriate antitoxoplasma therapy should be considered candidates for brain biopsy.

Prevention of relapse of histoplasmosis with itraconazole in patients with the acquired immunodeficiency syndrome

OBJECTIVE

To assess the efficacy and safety of itraconazole in preventing relapse of histoplasmosis after induction therapy with amphotericin B in patients with the acquired immunodeficiency syndrome (AIDS) and disseminated histoplasmosis.

DESIGN

A prospective, multicenter, open-label clinical trial, with follow-up for at least 52 weeks.

SETTING

Tertiary care hospitals participating in a clinical investigation sponsored by the National Institutes of Allergy and Infectious Diseases (AIDS Clinical Trial Group and Mycoses Study Group).

PATIENTS

Forty-two patients with AIDS who had successfully completed induction therapy for disseminated histoplasmosis amphotericin B, at least 15 mg/kg body weight given over 4 to 12 weeks.

INTERVENTIONS

Itraconazole, 200 mg given orally twice daily.

MAIN OUTCOME MEASURES

Response to therapy, specifically prevention of histoplasmosis relapse, was the main outcome measure. Secondary end points were survival and the effect of therapy on Histoplasma capsulatum variety capsulatum antigen levels in urine and serum. Plasma itraconazole concentrations were measured to document drug absorption and compliance with therapy.

RESULTS

The median follow-up was 109 weeks, and median survival was 98 weeks. Two relapses occurred (5%; 95% CI, 0.5% to 16%), one in a patient withdrawn from the study 18 weeks earlier and one in a patient who did not comply with the study therapy. Patients with elevated antigen levels at study entry showed clearance of antigen from urine and serum; urine specimens became negative in 43% of patients (CI, 26% to 59%), and serum specimens became negative in 75% of patients (CI, 56% to 94%). Only one patient discontinued treatment because of itraconazole toxicity (hypokalemia).

CONCLUSIONS

Itraconazole, 200 mg twice daily, is safe and effective in preventing relapse of disseminated histoplasmosis in patients with AIDS. Antigen clearance from blood and urine correlates with clinical efficacy.

[Primary prevention of cerebral toxoplasmosis in patients with HIV infection: results of a double-blind randomized trial, pyrimethamine versus placebo]

To assess the efficacy of pyrimethamine (Pyr) for primary prophylaxis of cerebral toxoplasmosis (CT) in HIV patients (pts), 554 pts were randomized in a double-blind, placebo-controlled trial (mean follow-up: 14 months). The intent-to-treat analysis found no significant difference in the incidence of ct at 1 year: 12% (Pyr) versus 13% (Pcb) nor in survival. Side-effects leading to stop the study drug were more frequent in Pyr group, especially cutaneous rashes: 8% (Pyr) versus 2% (Pcb).

[Risk factors of cerebral toxoplasmosis in patients with HIV infection: data of a primary prevention trial]

To identify risk factors for cerebral toxoplasmosis (CT) in HIV patients (pts) with positive serology for Toxoplasma gondii and CD4 < 200/mm3, data from the placebo group (N = 280) of a primary prophylaxis trial, were analyzed. The probability of onset of CT (n = 46) was, at one year, 13.1%. Three baseline variables were independently associated with a higher risk of CT: group IV non AIDS, AIDS stage and CD4 < 50/mm3. Initial titer of antibodies to Toxoplasma gondii was not.

Toxicity of clindamycin as prophylaxis for AIDS-associated toxoplasmic encephalitis. Community Programs for Clinical Research on AIDS

A double-blind, placebo-controlled trial was set up to compare clindamycin and pyrimethamine as prophylaxis for toxoplasmic encephalitis (TE) in HIV-infected patients at risk of the disorder. Interim analysis showed that clindamycin-treated patients were 4.4 (95% confidence interval 1.3-15.2) times more likely to experience an adverse effect that necessitated withdrawal of the study drug than those who received placebo. Diarrhoea and rash were reported in 16 (31%) and 11 (21%), respectively, of 52 patients treated with clindamycin (300 mg twice daily) compared with 2 (6%; p = 0.06) and none (p = 0.01) of the 32 placebo-treated patients. The clindamycin arm of the trial was prematurely terminated, although recruitment to the pyrimethamine arm continues.

A controlled trial comparing foscarnet with vidarabine for acyclovir-resistant mucocutaneous herpes simplex in the acquired immunodeficiency syndrome. The AIDS Clinical Trials Group

BACKGROUND AND METHODS

Most strains of herpes simplex virus that are resistant to acyclovir are susceptible in vitro to both foscarnet and vidarabine. We conducted a randomized trial to compare foscarnet with vidarabine in 14 patients with the acquired immunodeficiency syndrome (AIDS) and mucocutaneous herpetic lesions that had been unresponsive to intravenous therapy with acyclovir for a minimum of 10 days. The patients were randomly assigned to receive either foscarnet (40 mg per kilogram of body weight intravenously every 8 hours) or vidarabine (15 mg per kilogram per day intravenously) for 10 to 42 days. In the isolates of herpes simplex virus we documented in vitro resistance to acyclovir and susceptibility to foscarnet and vidarabine.

RESULTS

The lesions in all eight patients assigned to foscarnet healed completely after 10 to 24 days of therapy. In contrast, vidarabine was discontinued because of failure in all six patients assigned to receive it. The time to complete healing (P = 0.01), time to 50 percent reductions in the size of the lesions (P = 0.01) and the pain score (P = 0.004), and time to the end of viral shedding (P = 0.006) were all significantly shorter in the patients assigned to foscarnet. Three patients had new neurologic abnormalities while receiving vidarabine. No patient discontinued foscarnet because of toxicity. Although initial recurrences of herpes simplex infection after the index lesion had healed tended to be susceptible to acyclovir, acyclovir-resistant infection eventually recurred in every healed patient, a median of 42.5 days (range, 14 to 191) after foscarnet was discontinued.

CONCLUSIONS

For the treatment of acyclovir-resistant herpes simplex infection in patients with AIDS, foscarnet has superior efficacy and less frequent serious toxicity than vidarabine. Once the treatment is stopped, however; there is a high frequency of relapse.

In vivo additive antiretroviral effect of combined zidovudine and foscarnet therapy for human immunodeficiency virus infection (ACTG Protocol 053)

Zidovudine and foscarnet each have antiretroviral activity against human immunodeficiency virus (HIV) and, when combined in vitro, inhibit HIV replication in an additive or synergistic fashion. To determine if an in vivo additive or synergistic antiretroviral effect might result from combined therapy, six symptomatic HIV-infected patients were studied who had persistently quantifiable serum HIV p24 antigen despite 9-27 weeks of full-dose oral zidovudine therapy (1200 mg/day). These patients were given intravenous foscarnet (30 mg/kg every 8h) for 2 weeks with continued oral zidovudine for 14 days, followed by zidovudine alone for 6 months. Serum p24 antigen concentrations decreased in all six patients during the period of combined therapy by a mean 53% (P = .005). Subsequently, serum p24 antigen levels rose to the baseline value in four patients after 4-14 weeks. As predicted from in vitro studies, combined treatment with zidovudine and foscarnet resulted in an additive in vivo effect, but the effect was transient.

Clinical programs for clinical research on AIDS: description of a randomized prospective study of clindamycin versus pyrimethamine for prevention of Toxoplasma gondii infection

The risk of toxoplasmic encephalitis complicating AIDS appears largely limited to those HIV-infected patients with serologic evidence of past Toxoplasma gondii infection and low CD4 lymphocyte counts. The Community Programs for Clinical Research on AIDS has initiated a randomized, placebo-controlled trial to determine if clindamycin or pyrimethamine prophylactic regimens are effective and safe in preventing toxoplasmic encephalitis.