A randomized study of the utility of human immunodeficiency virus RNA measurement for the management of antiretroviral therapy.

To compare frequent measurement with infrequent measurement of human immunodeficiency virus (HIV) RNA levels in the management of antiretroviral therapy, we conducted a clinical strategy study of 206 HIV-infected patients who had <500 CD4 cells/mm(3). Patients were randomized (1.5:1) to undergo frequent monitoring (at baseline and every 2 months) or infrequent monitoring (at baseline and twice yearly), with CD4 cell counts determined every 2 months. Patients received unrestricted antiretroviral therapy. In the primary analysis (at month 6), the frequent group had a mean HIV RNA reduction (+/- standard deviation) of 0.93+/-0.79 log(10) copies/mL, versus 0.48+/-0.83 log(10) copies/mL for the infrequent group (P=.0002). A trend (P=.1) toward improved survival was seen in the frequent group. Given this improved virological response, more frequent HIV RNA measurement than is recommended in published guidelines (every 3-4 months) may be appropriate.

Human immunodeficiency virus-infected patients receiving highly active antiretroviral therapy maintain activated CD8+ T cell subsets as a strong adaptive immune response to cytomegalovirus.

CD8(+) T lymphocyte function specific for human cytomegalovirus (CMV) was evaluated in 14 patients infected with human immunodeficiency virus (HIV) receiving highly active antiretroviral therapy (HAART) and 26 CMV-seropositive donors without HIV infection. Fifty-seven percent of the HIV-infected group had CMV-specific cytolytic activity in freshly isolated peripheral blood mononuclear cells (PBMC) against targets expressing CMV pp65. Both interferon (IFN)-gamma secretion by CD8(+) T cells and the frequency of human leukocyte antigen (HLA)-tetramer-positive T cells in HLA-A*0201-positive HIV-infected subjects correlated with CMV-specific cytolysis. In contrast, PBMC from healthy CMV-seropositive donors did not have either measurable CMV-specific cytolysis or secretion of IFN-gamma without in vitro stimulation. The T helper response to CMV antigens was vigorous in healthy CMV-seropositive donors but low in the cohort of HIV-infected patients. Potent CD8(+) cytotoxic T lymphocyte responses to CMV in HIV-infected patients receiving HAART is the converse of what is found in healthy CMV-seropositive subjects and may be the predominant adaptive immune response against CMV in HIV-infected patients.

Sequencing of protease inhibitor therapy: insights from an analysis of HIV phenotypic resistance in patients failing protease inhibitors.

OBJECTIVE: To characterize the pattern of HIV-1 susceptibility to protease inhibitors in patients failing an initial protease inhibitor-containing regimen. DESIGN: A cross-sectional analysis of antiretroviral susceptibility. SETTING: HIV clinics in six metropolitan areas. PATIENTS: Eighty-eight HIV-infected adults with HIV RNA > 400 copies/ml after > or = 6 months of antiretroviral therapy, including the use of one protease inhibitor for > or = 3 months. MEASUREMENTS: The frequency and magnitude of decreased susceptibility, measured with a phenotypic assay using recombinant constructs, to five protease inhibitors. Decreased susceptibility was defined as > 2.5-fold increase in the 50% inhibitory concentration (IC50) compared with drug sensitive control virus. RESULTS: At study entry, patients were being treated with nelfinavir (63%), indinavir (25%), or another protease inhibitor (11%). HIV isolates from these patients were susceptible (fold change < 2.5) to all five protease inhibitors in 18% of patients and to none in 8%. Isolates from patients receiving nelfinavir were less likely to have reduced susceptibility to other protease inhibitors than isolates from patients treated with indinavir (P < 0.001) or one of the other three agents (P < 0.001), even after adjustment for the duration of prior protease inhibitor use. Reduced susceptibility to saquinavir and amprenavir was observed significantly less frequently than for the other protease inhibitors. CONCLUSION: The frequency of protease inhibitor cross-resistance and the magnitude of changes in susceptibility varied according to the initial protease inhibitor used in the failing treatment regimen. Significantly less protease inhibitor cross-resistance was demonstrated for isolates from patients failing a nelfinavir-containing regimen compared with those from patients receiving other protease inhibitors.

Concentration-targeted phase I trials of atevirdine mesylate in patients with HIV infection: dosage requirements and pharmacokinetic studies. The ACTG 187 and 199 study teams.

RATIONALE: To determine the dosage requirements and pharmacokinetics of atevirdine, a non-nucleoside reverse transcriptase inhibitor and its N-dealkylated metabolite (N-ATV) during phase I studies in patients receiving atevirdine alone or in combination with zidovudine. DESIGN: Two open label, phase I studies conducted by the adult AIDS Clinical Trials Group (ACTG) in which atevirdine was administered every 8 h with weekly dosage adjustments to attain targeted trough plasma atevirdine concentrations. SETTING: Five Adult AIDS Clinical Trials Units. PATIENTS: Fifty patients (ACTG 199; n = 20 and ACTG 187; n = 30) with HIV-1 infection and < or =500 CD4+ lymphocytes/mm3. INTERVENTION: ACTG 199; 12 weeks of therapy with atevirdine (dose-adjusted to achieve plasma trough atevirdine concentrations of 5-10 microM) and zidovudine (200 mg every 8 h). ACTG 187: 12 weeks of atevirdine monotherapy with atevirdine doses adjusted to achieve escalating, targeted trough plasma concentration ranges (5-13, 14-22, and 23-31 microM). MEASUREMENTS: ACTG 199: atevirdine, N-ATV and zidovudine trough determinations weekly (all patients) and intensive pharmacokinetics (selected patients) prior to and at 6 and 12 weeks during combination therapy. ACTG 187: atevirdine and N-ATV trough concentrations over a 12 week period. Intensive pharmacokinetic studies were conducted prior to and at 4 and/or 8 weeks during atevirdine monotherapy in female patients. RESULTS: Atevirdine plasma concentrations demonstrated considerable interpatient variability which was minimized by the adjustment of maintenance doses (range: 600-3900 mg/day) to achieve the desired trough concentrations. In ACTG 187, the mean number of weeks to attain the target value, and the percentage of patients who attained the target, was group I (5-11 microM): 2.7+/-2.4 weeks (92%); group II (12-21 microM): 2.6+/-1.8 (64%); and group III (22-31 microM): 7.0+/-5.6 weeks (27%). In ACTG 199 it was 3.2+/-5.2 weeks (95%) to achieve a 5-10 microM trough. Atevirdine demonstrated a mono- or bi-exponential decline among most of the patients studied after the first dose. During multiple-dosing a number of patterns of atevirdine disposition were observed including; rapid absorption with Cmax at 0.5-1 h, delayed absorption with Cmax at 3-4 h; minimal Cmax to Cmin fluctuation and Cmax to Cmin ratios of > 4. N-ATV (an inactive metabolite) patterns were characterized on day one by rapid appearance of the metabolite which peaked at 2-3 h after the dose and declined in a mono- or bi-exponential manner. At steady-state N-ATV patterns demonstrated minimal Cmax to Cmin fluctuations with some of the patients having more stable plasma N-ATV concentrations, while others had greater fluctuations week to week. CONCLUSIONS: Considerable interpatient variability was noted in the pharmacokinetics of atevirdine. The variation in drug disposition was reflected in the range of daily doses required to attain the targeted trough concentrations. Atevirdine metabolism did not appear to reach saturation during chronic dosing in many of our patients, as reflected by the pattern of N-ATV/ATV ratios in plasma and saturation was not an explanation for the variation in dosing requirements. No apparent differences were noted between males and females, and atevirdine did not appear to influence zidovudine disposition.

Epidemiology of central nervous system infections.

The radiologist frequently is asked to contribute to the diagnosis of a patient with central nervous system infections, although radiologic findings usually are nonspecific. The radiologist can consider diagnostic possibilities with more accuracy if the clinician includes accurate demographic and epidemiologic information. This article organizes a broad range of central nervous system infections into demographic and epidemiologic perspective.

Early mycological treatment failure in AIDS-associated cryptococcal meningitis.

Cryptococcal meningitis causes significant morbidity and mortality in persons with AIDS. Of 236 AIDS patients treated with amphotericin B plus flucytosine, 29 (12%) died within 2 weeks and 62 (26%) died before 10 weeks. Just 129 (55%) of 236 patients were alive with negative cerebrospinal fluid (CSF) cultures at 10 weeks. Multivariate analyses identified that titer of cryptococcal antigen in CSF, serum albumin level, and CD4 cell count, together with dose of amphotericin B, had the strongest joint association with failure to achieve negative CSF cultures by day 14. Among patients with similar CSF cryptococcal antigen titers, CD4 cell counts, and serum albumin levels, the odds of failure at week 10 for those without negative CSF cultures by day 14 was five times that for those with negative CSF cultures by day 14 (odds ratio, 5.0; 95% confidence interval, 2.2-10.9). Prognosis is dismal for patients with AIDS-related cryptococcal meningitis. Multivariate analyses identified three components that, along with initial treatment, have the strongest joint association with early outcome. Clearly, more effective initial therapy and patient management strategies that address immune function and nutritional status are needed to improve outcomes of this disease.

Successful short-term suppression of clarithromycin-resistant Mycobacterium avium complex bacteremia in AIDS. California Collaborative Treatment Group.

During a randomized study of clarithromycin plus clofazimine with or without ethambutol in patients with AIDS and Mycobacterium avium complex (MAC) bacteremia, eight participants received additional antimycobacterial drugs following the detection of a clarithromycin-resistant isolate (MIC, > 8 micrograms/mL). A macrolide (seven received clarithromycin, one azithromycin) and clofazimine were continued; additional treatment included various combinations of ethambutol, ciprofloxacin, amikacin, and rifabutin. After the detection of a resistant isolate and before receipt of additional antimycobacterials, the median peak MAC colony count in blood was 105 cfu/mL (range, 8-81,500 cfu/mL). After additional antimycobacterials, the median nadir MAC colony count was 5 cfu/mL (range, 0-110 cfu/mL). Five (63%) of eight patients had a > or = 1 log10 decrease, including two who achieved negative blood cultures; all of these responses occurred in patients originally assigned to clarithromycin plus clofazimine. Treatment of clarithromycin-resistant MAC bacteremia that emerges during clarithromycin-based treatment can decrease levels of bacteremia and transiently sterilize blood cultures.

Phase I study of atevirdine mesylate (U-87201E) monotherapy in HIV-1-infected patients.

The safety, tolerability, and antiviral activity of atevirdine (ATV), a nonnucleoside reverse transcriptase inhibitor, were studied in a phase I/II clinical trial (ACTG 187) of patients with CD4 counts < or =500/mm3. In all, 34 HIV-1-infected patients were randomized to receive ATV for 12 weeks in doses chosen to achieve one of three serum trough levels: 5 to 13 microM, 14 to 22 microM, or 23 to 31 microM. Rash was the most common adverse event, with a grade 3 or 4 rash occurring in 4 patients. No significant change from baseline in HIV-1 plasma RNA mean copy number was detected at week 4 (+0.09 log10 copies/ml; p = .30). However, some evidence indicated moderate antiviral activity at week 4, based on median changes in CD4 count (+23/mm3; p = .05), and viral peripheral blood mononuclear cell (PBMC) titer (-0.68 log10) copies/ml; p = .03). In addition, 2 of 4 patients with detectable baseline serum p24 antigen showed declines of >50%. HIV-1 resistance to ATV was detected in 41% of patients and was most commonly associated with RT mutations K103N and Y181C. In contrast, the Y181C mutation was not detected in ATV-resistant isolates obtained from patients enrolled in ACTG 199, a study of ATV given in combination with zidovudine. Under the conditions of this study, ATV failed to demonstrate significant antiretroviral activity. However, transient in vivo activity might have been obscured by rapid development of resistance coupled with inadequate sampling at early time points following initiation of ATV therapy.

A randomized evaluation of ethambutol for prevention of relapse and drug resistance during treatment of Mycobacterium avium complex bacteremia with clarithromycin-based combination therapy. California Collaborative Treatment Group.

Patients with AIDS and Mycobacterium avium complex (MAC) bacteremia are at high risk for relapse and emergence of resistant isolates during monotherapy with clarithromycin. Ninety-five AIDS patients with MAC bacteremia received clarithromycin plus clofazimine, with or without ethambutol, in a prospective, multicenter, randomized open-label trial. Of 80 patients with positive baseline cultures, sterilization or a 2 log10 reduction in colony-forming units of MAC in two consecutive blood cultures occurred in 69% of both groups. There were nine relapses in the two-drug arm and three in the three-drug arm. Kaplan-Meier estimates of risk of relapse at 36 weeks were 68% and 12%, respectively (P = .004). All relapse isolates were resistant to clarithromycin. Median time to clarithromycin resistance was 16 weeks with two drugs and 40 weeks with three drugs (P = .004). Ethambutol reduced relapses and emergence of clarithromycin resistance and should be considered an essential component of clarithromycin-based therapies for MAC bacteremia.

Phase I study of atevirdine, a nonnucleoside reverse transcriptase inhibitor, in combination with zidovudine for human immunodeficiency virus type 1 infection. ACTG 199 Study Team.

Twenty patients were enrolled in a phase I clinical trial of atevirdine, a nonnucleoside reverse transcriptase inhibitor (NNRTI), given in combination with zidovudine for treatment of human immunodeficiency virus type 1 (HIV-1) infection. Fifteen patients had received no previous antiretroviral therapy. HIV-1 isolates obtained at 6-week intervals were tested for sensitivity to atevirdine and zidovudine. Two patients developed a rash within 2 weeks of enrollment, and 1 of these developed concomitant fever and hepatitis. No hematopoietic, neurologic, or pancreatic toxicities were observed. Atevirdine had considerable initial interpatient pharmacokinetic variability. Forty-seven percent of patients treated with atevirdine plus zidovudine had increased CD4 lymphocyte counts, and HIV isolates from 62% of patients remained sensitive to atevirdine after 24 weeks of therapy. Atevirdine plus zidovudine was well-tolerated. Additional studies should be done to determine the role of atevirdine in the therapy for HIV infection.

The tolerance for zidovudine plus thrice weekly or daily trimethoprim-sulfamethoxazole with and without leucovorin for primary prophylaxis in advanced HIV disease. California Collaborative Treatment Group.

PURPOSE: Trimethoprim-sulfamethoxazole (TMP/SMX) is the preferred agent for prophylaxis of Pneumocystis carinii pneumonia (PCP) in patients with HIV infection, but frequent adverse events limit its usefulness. Intermittent dosing and supplementation with leucovorin have been tried in attempts to improve tolerance. We evaluated these strategies in persons with advanced HIV disease. METHOD: One hundred seven patients were enrolled. All had HIV infection, < 200 CD4+ lymphocytes per mm3, and no history of PCP. Fifty-two were randomized to TMP/SMX twice daily (BID); of these, 26 were randomized to leucovorin with each dose. Fifty-five patients were randomized to TMP/SMX (BID) 3 times per week; of these, 27 were randomized to leucovorin with each dose. All patients took zidovudine concurrently. RESULTS: The 24-week risk of discontinuation due to protocol-defined limiting toxicity was 24% with thrice-weekly TMP/SMX versus 42% with daily TMP/SMX (risk ratio 0.4; 95% CI 0.2 to 1.0). The risks of discontinuation for any reason were 41% and 59% (risk ratio 0.4; 95% CI 0.2 to 0.8). Clinical toxicity, such as headache and gastrointestinal distress, accounted for the observed difference in tolerance between dosing regimens. The 24-week risk of discontinuation due to protocol-defined toxicity was 33% in both the leucovorin and non-leucovorin groups (risk ratio 1.1; 95% CI 0.5 to 2.5). The risks of discontinuation for any reason were 53% and 47% (risk ratio 0.8; 95% CI 0.3 to 1.7). CONCLUSION: Intermittent therapy with TMP/SMX BID thrice weekly is better tolerated than daily BID therapy. Leucovorin use does not improve tolerance for chronic TMP/SMX dosing in AIDS, even among patients taking tablets daily.

Fluconazole combined with flucytosine for treatment of cryptococcal meningitis in patients with AIDS.

Treatment of cryptococcal meningitis with amphotericin B or fluconazole is often unsuccessful; in only 35%-40% of cases do CSF cultures become negative by 10 weeks after initiation of such therapy. We conducted a prospective, open-label clinical trial involving persons with AIDS to determine whether the rate of clinical success would improve when fluconazole (400 mg daily) was combined with flucytosine (150 mg/kg daily). At the conclusion of 10 weeks of therapy, 75% (95% confidence interval, 58%-87%) of 32 subjects' CSF cultures were negative. The Kaplan-Meier estimate of clinical success at 10 weeks was 63% (95% confidence interval, 48%-82%). The median time to negativity of the CSF culture was 23 days. Toxic side effects that were sufficiently severe to lead to the withdrawal of flucytosine were observed in nine subjects (28%). In this pilot study of fluconazole combined with flucytosine, the rate of clinical success at 10 weeks was greater than that previously reported with regard to the use of fluconazole alone or amphotericin B alone.

The individual microbiologic effect of three antimycobacterial agents, clofazimine, ethambutol, and rifampin, on Mycobacterium avium complex bacteremia in patients with AIDS.

The individual antibacterial activities of clofazimine, ethambutol, and rifampin in the treatment of Mycobacterium avium complex bacteremia in patients with AIDS were determined. Sixty human immunodeficiency virus 1-infected patients who had at least one blood culture positive for M. avium complex were randomized to receive either clofazimine (200 mg), ethambutol (15 mg/kg), or rifampin (600 mg) once daily for 4 weeks. Only ethambutol resulted in a statistically significant reduction in the level of mycobacteremia. The median change in individual baseline colony counts was -0.60 log10 cfu/mL after 4 weeks of ethambutol (P = .046). In contrast, median changes in individual baseline colony counts were -0.2 log10 cfu/mL and +0.2 log10 cfu/mL for clofazimine and rifampin, respectively (both, P > .4). Ethambutol had greater antibacterial activity, as determined by changes in the level of mycobacteremia, than either rifampin or clofazimine, supporting its continued use in combination with other agents in the treatment of M. avium infection.

Performance evaluation in multicenter clinical trials: development of a model by the AIDS Clinical Trials Group.

The AIDS Clinical Trials Group (ACTG), supported by the National Institute of Allergy and Infectious Diseases (NIAID), is the largest federally funded program of AIDS clinical trials. It is a collaboration involving 59 institutions and affiliated clinical centers, known as AIDS Clinical Trials Units (ACTUs), NIAID staff, and a Statistical and Data Analysis Center (SDAC). An institutional evaluation tool was developed to evaluate ACTU performance, distinguish between clinical centers with superior performance and those not meeting standards, and assist NIAID in allocating funding based on performance. The evaluation tool was designed to reflect the many distinguishing features of ACTG study protocols and clinical trial centers in order to measure performance objectively. The evaluation focused on assessing the financial resources expended by the ACTU in recruiting, treating, and following study patients during the evaluation period; the number of women and minorities enrolled; and the ACTU's scientific contributions to the ACTG. To help quantify the ACTU's performance in enrolling study subjects, a formula was derived to assess the total effort required to screen, enroll, treat, and assess subjects participating in ACTG studies. A weighting system was developed for each study protocol to account for the variations in effort and resources required by the different protocols. Future directions in the ACTG evaluation process include strategies to evaluate performance in relation to quality of data and to determine ways in which the evaluation process can be used to enhance the achievement of programmatic goals.

Alternating and intermittent regimens of zidovudine and dideoxycytidine in patients with AIDS or AIDS-related complex.

OBJECTIVE: To determine whether alternating regimens consisting of zidovudine and 2',3'-dideoxycytidine (ddC) reduce the toxicity and maintain or increase the antiretroviral effect associated with each drug alone. DESIGN: An unblinded, randomized (phase II) clinical trial in which seven treatment regimens were compared. SETTING: Outpatient clinics of 12 AIDS Clinical Trials Units. PATIENTS: One hundred thirty-one patients with the acquired immunodeficiency syndrome (AIDS) or AIDS-related complex and serum p24 antigenemia (> or = 70 pg/mL). INTERVENTION: Treatments included weekly or monthly alternating zidovudine (200 mg every 4 hours) and ddC (0.01 or 0.03 mg/kg body weight every 4 hours); weekly intermittent zidovudine, 200 mg every 4 hours, or ddC, 0.03 mg/kg every 4 hours; and continuous zidovudine. MEASUREMENTS: Toxicity, CD4 cell counts, serum p24 antigen levels, and clinical end points. Data were analyzed for the first 48 weeks of therapy (median follow-up, 40 weeks). RESULTS: Hematologic toxicity was significantly less frequent in patients who received zidovudine therapy every other week (11% to 15%) or every other month (11% to 14%) than in those who received continuous zidovudine therapy (33%) (P < 0.02). Weekly alternating therapy with zidovudine and ddC, 0.03 mg/kg, or intermittent therapy with ddC, 0.03 mg/kg, produced high rates of peripheral neuropathy (41% and 50%, respectively). Neuropathy occurred in 10% to 21% of patients in the other three alternating-therapy limbs and in 17% of patients receiving zidovudine alone (intermittently or continuously). Initial increases in CD4 cell counts were sustained in three alternating-therapy limbs, but counts returned to baseline by week 28 in the remaining limbs. The median weight gain at week 48 was significantly greater in patients treated with alternating regimens (0.9 to 3.8 kg) compared with those treated with continuous zidovudine therapy (-0.7 kg) (P = 0.008). Patients treated with alternating regimens and those treated with continuous zidovudine had similarly sustained decreases in p24 antigen levels. CONCLUSIONS: These findings suggest that alternating therapy with zidovudine and ddC reduces the toxicity associated with each drug alone while maintaining strong antiretroviral activity.

Prevalence of neurosyphilis in human immunodeficiency virus-infected patients with latent syphilis.

PURPOSE: A prospective study was done to determine the prevalence of confirmed neurosyphilis (cerebrospinal fluid [CSF] Venereal Disease Research Laboratory [VDRL]-reactive) in human immunodeficiency virus (HIV)-infected patients with latent syphilis (reactive serum rapid plasma reagin [RPR] and microhemagglutination-Treponema pallidum [MHA-TP]). PATIENTS AND METHODS: All HIV-infected patients seen for their first visit at the Los Angeles County/University of Southern California Medical Center AIDS Clinic from June through December 1990 were screened for latent syphilis. Those with reactive serum RPRs and MHA-TPs who had not received recent (within 6 months) therapy for syphilis were offered diagnostic CSF sampling. RESULTS: A total of 312 patients were screened, of whom 71 (22.8%) had reactive serum RPRs and MHA-TPs. Thirty-three of these patients (47%) had diagnostic CSF sampling (26 refused lumbar puncture or were lost to follow-up; 12 had had recent therapy for syphilis and thus did not have CSF sampling). Among the 33 patients who had CSF sampling, 20 (60.6%) had normal CSF profiles (white blood cell count less than 8/mm3; protein less than 0.60 g/L; glucose greater than 2.8 mmol/L) and nonreactive CSF VDRLs. Ten of the 33 patients (30.3%) had abnormal CSF profiles and nonreactive CSF VDRLs, and three of 33 (9.1%) had reactive CSF VDRLs. CONCLUSIONS: Asymptomatic neurosyphilis was found in 9.1% of our patient population undergoing CSF sampling, giving a 1.0% prevalence of CSF VDRL-reactive neurosyphilis in the population we screened. The abnormal CSF findings may have been due to either nonreactive CSF VDRL neurosyphilis, central nervous system infection with HIV, or infection with some unrecognized agent.

Treatment of Mycobacterium avium complex bacteremia in AIDS with a four-drug oral regimen. Rifampin, ethambutol, clofazimine, and ciprofloxacin. The California Collaborative Treatment Group.

OBJECTIVE: To determine the quantitative microbiologic response and the clinical response of patients with Mycobacterium avium complex bacteremia and AIDS to an oral antimycobacterial regimen. DESIGN: A phase II, multicenter clinical trial. SETTING: Four university-affiliated medical centers. PATIENTS: Forty-one patients with HIV infection who had at least two consecutive blood cultures positive for M. avium complex and who had not received previous antimycobacterial therapy were enrolled in the study. Thirty-one patients were evaluable with regard to the efficacy of the oral regimen. INTERVENTIONS: Patients received a combination of orally administered rifampin (600 mg), ethambutol (15 mg/kg body weight), clofazimine (100 mg once daily), and ciprofloxacin (750 mg twice daily) for 12 weeks. Parenterally administered amikacin, 7.5 mg/kg daily for 4 weeks after the first 4 weeks of oral therapy, was used at the discretion of the individual investigator. MEASUREMENTS: Clinical symptoms, Karnofsky scores, and adverse events were monitored. Colony counts for M. avium complex were determined. MAIN RESULTS: The mean logarithmic (log) baseline colony count decreased from 2.1 to 0.7 after 4 weeks of oral therapy (P less than 0.001). Suppression of bacteremia was sustained throughout therapy. Thirteen patients (42%) became culture negative during therapy. The mean duration of treatment was 9.7 weeks. Nineteen evaluable patients (61%) completed 12 weeks of therapy. Adverse reactions to one or more agents were common. CONCLUSIONS: A rapid reduction in symptoms and bacteremia can be achieved as early as week 2 of therapy using an oral regimen of rifampin, ethambutol, clofazimine, and ciprofloxacin. Colony counts rose dramatically after therapy was discontinued, suggesting that more prolonged periods of therapy are necessary to eradicate systemic infection.