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Biomedical subjects

D L Cohn

Publications and source records attributed to D L Cohn.

At least 19 recordsLinked to original sources

Comparison of intermittent ethambutol with rifampicin-based regimens in HIV-infected adults with PTB, Kampala.

BACKGROUND: The human immunodeficiency virus (HIV) is a key factor responsible for the high rates of tuberculosis (TB) in sub-Saharan Africa. Treatment of TB with rifampicin (R, RMP) containing short-course regimens is highly effective in HIV-infected adults. We conducted a study to compare the efficacy and safety of intermittent ethambutol (E, EMB) with two RMP-containing regimens to treat pulmonary TB in HIV-infected patients. SETTING: National Tuberculosis Treatment Centre, Mulago Hospital, Kampala, Uganda. DESIGN: This was a prospective cohort compared to two non-randomised control groups. The study group and the two control arms were treated with 2 months of isoniazid (H), RMP, pyrazinamide (Z) and EMB followed by 6 E3H3 for the study group and 4HR or 6HR for controls. RESULTS: Between April 1993 and March 2000, 136 patients were enrolled in the 2EHRZ/E3H3 arm, 147 in the 2EHRZ/4HR arm and 266 in the 2EHRZ/6HR arm. The relapse rate was 18.2 per 100 person-years observation (PYO) for the study regimen compared to 9.7/100 PYO (P = 0.0063) and 4.8/100 PYO (P = 0.0001) in patients treated with 2 EHRZ/4HR or 2EHRZ/6HR, respectively. CONCLUSION: The 2EHRZ/6E3H3 regimen is safe and effective but has a significant risk of relapse.

AIDS-Related Opportunistic Infections↗

The safety and efficacy of adefovir dipivoxil in patients with advanced HIV disease: a randomized, placebo-controlled trial.

OBJECTIVE: Efficacy and safety of adefovir dipivoxil (adefovir) added to background antiretroviral therapy in advanced HIV disease. DESIGN: Randomized, double-blind, placebo-controlled multicenter trial. SETTING: Fifteen clinical trial units providing HIV primary care. PARTICIPANTS: Adults with CD4 cell count < or = 100 x 10(6)/l, or 101-200 x 10(6)/l with prior nadir < or = 50 x 10(6)/l. INTERVENTIONS: Oral adefovir or placebo 120 mg once daily. MAIN OUTCOME MEASURES: Survival, cytomegalovirus (CMV) disease, plasma HIV-RNA, CD4 cell count, grade 4 drug toxicity, permanent drug discontinuation due to toxicity. RESULTS: Among the 253 patients assigned adefovir and the 252 assigned placebo, respectively, 17 and 16 died (P = 0.88), and four and eight experienced CMV disease (P = 0.25). Mean change in log(10) plasma HIV-RNA in the adefovir and placebo groups, respectively, was 0.09 and -0.03 copies/ml at 6 months (P = 0.22) and 0.06 and -0.02 at 12 months (P = 0.87). Changes in CD4 cell counts were not different between groups. At 12 months the cumulative percent with proximal renal tubular dysfunction (PRTD) was 17% in the adefovir group and 0.4% in the placebo group (P < 0.0001, log rank test). Median time to resolution of PRTD was 15 weeks among patients assigned adefovir, and 16% of patients did not resolve completely 41 weeks after onset. More drug discontinuations occurred in the adefovir group than in the placebo group. CONCLUSIONS: No virologic or immunologic benefit was observed when adefovir was added to background antiretroviral therapy in advanced HIV disease, and adefovir was associated with considerable nephrotoxicity. This study does not support the use of adefovir for treatment of advanced HIV disease in pretreated patients.

Adenine↗

A review of efficacy studies of 6-month short-course therapy for tuberculosis among patients infected with human immunodeficiency virus: differences in study outcomes.

Six-month regimens that include rifampin for the treatment of tuberculosis in patients without human immunodeficiency virus (HIV) infection are recommended because of low percentage of relapses. Whether a similar duration of therapy should be used to treat tuberculosis in HIV-infected patients is unclear. Six studies of patients with HIV-infection and 3 of patients without HIV infection were reviewed and compared. The studies differed in terms of design, eligibility criteria, site of disease, frequency of dosing, dose administration methods, and outcome definitions. Among HIV-infected patients, the following percentages were found: cure, 59.4%--97.1%; treatment success, 34.0%--100%; effective treatment, 29.4%--88.2%; and relapse, 0%--10%. In those without HIV infection, percentages were as follows: cure, 62.3%--88.0%; treatment success, 91.2%--98.8%; effective treatment, 70.6%--83.8%; and relapse, 0%--3.4%. Although the rate of relapse appeared to be higher in some studies of HIV-infected patients with tuberculosis, this review demonstrates the limitation in the use of relapse as the exclusive outcome of interest when comparing studies.

AIDS-Related Opportunistic Infections↗

Breaking the camel's back: multicenter clinical trials and local institutional review boards.

Clinical research has undergone remarkable and beneficial expansion in the past 25 years, but with this growth has come an unprecedented increase in workload for the human subjects protection system. Recently, a major change in federal oversight of local institutional review boards (IRBs) became evident. Although it was not announced publicly, in 1998 and 1999 federal regulatory actions against local IRBs increased threefold. Particularly notable was the marked increase in regulatory actions taken against the IRBs of academic medical centers (1 in 1997 compared with 14 in 1999). Ironically, this apparent federal crackdown began at the same time that two federal review panels called for major changes in the regulations governing local IRBs. A key factor in the current crisis in the function of local IRBs is the ascendance of multicenter clinical trials as the dominant form of clinical research. Local IRBs were not designed to handle the initial evaluation and ongoing review required by the rapidly increasing number of multicenter clinical trials. Furthermore, local IRB review of the thousands of safety reports from multicenter clinical trials monopolizes resources without promoting patient safety. Instead of rigid enforcement of outmoded regulations that do not contribute to patient safety, the responsibilities of the local IRB in the oversight of multicenter clinical trials must be systematically evaluated.

Academic Medical Centers↗

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.

Adult↗

Treatment of latent tuberculosis infection: renewed opportunity for tuberculosis control.

New recommendations for targeted tuberculin testing and treatment of latent tuberculosis (TB) infection have recently been published. Changes in nomenclature from screening to targeted tuberculin testing and from preventive therapy to treatment of latent TB infection (LTBI) are intended to promote more widespread implementation by programs and health care providers. Targeted tuberculin testing is designed to identify persons at high risk for TB and is discouraged for persons at low risk. New recommendations for treatment of LTBI in both human immunodeficiency virus (HIV)-infected and HIV-uninfected patients include isoniazid for 9 months as the preferred regimen: isoniazid for 6 months based on local program conditions, rifampin and pyrazinamide for 2 months, and rifampin for 4 months. Treatment monitoring now places greater emphasis on clinical, rather than routine, laboratory monitoring. More widespread implementation of targeted tuberculin testing and treatment of LTBI is an important control strategy that will enhance efforts to eliminate TB in the United States.

Antibiotics, Antitubercular↗

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).

AIDS-Related Opportunistic Infections↗

Coccidioidomycosis meningitis with massive dural and cerebral venous thrombosis and tissue arthroconidia.

To our knowledge we report the first case of meningitis from Coccidioides immitis associated with massive dural and cerebral venous thrombosis and with mycelial forms of the organism in brain tissue. The patient was a 43-year-old man with late-stage acquired immunodeficiency syndrome (AIDS) whose premortem and postmortem cultures confirmed C immitis as the only central nervous system pathogenic organism. Death was attributable to multiple hemorrhagic venous infarctions with cerebral edema and herniation. Although phlebitis has been noted parenthetically to occur in C immitis meningitis in the past, it has been overshadowed by the arteritic complications of the disease. This patient's severe C immitis ventriculitis with adjacent venulitis appeared to be the cause of the widespread venous thrombosis. AIDS-related coagulation defects may have contributed to his thrombotic tendency.

AIDS-Related Opportunistic Infections↗

A randomized, placebo-controlled study of rifabutin added to a regimen of clarithromycin and ethambutol for treatment of disseminated infection with Mycobacterium avium complex.

Current guidelines suggest that disseminated Mycobacterium avium complex (MAC) infection be treated with a macrolide plus ethambutol or rifabutin or both. From 1993 to 1996, 198 AIDS patients with MAC bacteremia participated in a prospective, placebo-controlled trial of clarithromycin (500 mg b.i.d.) plus ethambutol (1,200 mg/d), with or without rifabutin (300 mg/d). At 16 weeks, 63% of patients in the rifabutin group and 61% in the placebo group (P = .81) had responded bacteriologically. Changes in clinical symptoms and time to survival were similar in both groups. Development of clarithromycin resistance during therapy was similar in the two groups; of patients who had a bacteriologic response, however, only 1 of 44 (2%) receiving rifabutin developed clarithromycin resistance, vs. 6 of 42 (14%) in the placebo group (P = .055). Thus, rifabutin had no impact on bacteriologic response or survival but may protect against development of clarithromycin resistance in those who respond to therapy.

AIDS-Related Opportunistic Infections↗

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.

AIDS-Related Opportunistic Infections↗

Acupuncture and amitriptyline for pain due to HIV-related peripheral neuropathy: a randomized controlled trial. Terry Beirn Community Programs for Clinical Research on AIDS.

CONTEXT: Peripheral neuropathy is common in persons infected with the human immunodeficiency virus (HIV) but few data on symptomatic treatment are available. OBJECTIVE: To evaluate the efficacy of a standardized acupuncture regimen (SAR) and amitriptyline hydrochloride for the relief of pain due to HIV-related peripheral neuropathy in HIV-infected patients. DESIGN: Randomized, placebo-controlled, multicenter clinical trial. Each site enrolled patients into 1 of the following 3 options: (1) a modified double-blind 2 x 2 factorial design of SAR, amitriptyline, or the combination compared with placebo, (2) a modified double-blind design of an SAR vs control points, or (3) a double-blind design of amitriptyline vs placebo. SETTING: Terry Beirn Community Programs for Clinical Research on AIDS (HIV primary care providers) in 10 US cities. PATIENTS: Patients with HIV-associated, symptomatic, lower-extremity peripheral neuropathy. Of 250 patients enrolled, 239 were in the acupuncture comparison (125 in the factorial option and 114 in the SAR option vs control points option), and 136 patients were in the amitriptyline comparison (125 in the factorial option and 11 in amitriptyline option vs placebo option). INTERVENTIONS: Standardized acupuncture regimen vs control points, amitriptyline (75 mg/d) vs placebo, or both for 14 weeks. MAIN OUTCOME MEASURE: Changes in mean pain scores at 6 and 14 weeks, using a pain scale ranging from 0.0 (no pain) to 1.75 (extremely intense), recorded daily. RESULTS: Patients in all 4 groups showed reduction in mean pain scores at 6 and 14 weeks compared with baseline values. For both the acupuncture and amitriptyline comparisons, changes in pain score were not significantly different between the 2 groups. At 6 weeks, the estimated difference in pain reduction for patients in the SAR group compared with those in the control points group (a negative value indicates a greater reduction for the "active" treatment) was 0.01 (95% confidence interval [CI], -0.11 to 0.12; P=.88) and for patients in the amitriptyline group vs those in the placebo group was -0.07 (95% CI, -0.22 to 0.08; P=.38). At 14 weeks, the difference for those in the SAR group compared with those in the control points group was -0.08 (95% CI, -0.21 to 0.06; P=.26) and for amitriptyline compared with placebo was 0.00 (95% CI, -0.18 to 0.19; P=.99). CONCLUSIONS: In this study, neither acupuncture nor amitriptyline was more effective than placebo in relieving pain caused by HIV-related peripheral neuropathy.

Acupuncture Therapy↗

Long-term outcomes of treatment of Mycobacterium avium complex bacteremia using a clarithromycin-containing regimen.

OBJECTIVES: To describe the long-term outcomes of treatment of AIDS-related Mycobacterium avium complex (MAC) bacteremia using a standard clarithromycin-based regimen. DESIGN: Retrospective study of patients with MAC bacteremia diagnosed between April 1992 and April 1995. SETTING: An urban AIDS clinic SUBJECTS: One hundred seventy-six consecutive patients with MAC bacteremia. INTERVENTIONS: Clarithromycin 500 mg twice daily, ethambutol 800 or 1200 mg daily, and clofazimine 100 mg daily. MAIN OUTCOME MEASURES: Late treatment failure (defined as a positive blood culture more than 90 days after starting treatment), clarithromycin susceptibility of initial and treatment-failure isolates, DNA fingerprinting of isolates from treatment failures. RESULTS: Two out of 176 (1.1%) baseline isolates were resistant to clarithromycin. One hundred and fifty-one patients were treated for MAC bacteremia, 144 (95%) with the standard regimen. Of the 117 patients who survived > 90 days after starting therapy, 25 (21%) met the criteria for late treatment failure. Of the 22 treatment-failure isolates available for susceptibility testing, 19 (86%) were resistant to clarithromycin. Therefore, 13% of patients treated using the standard regimen (19 out of 144) had treatment failure associated with the emergence of clarithromycin resistance. Using logistic regression, non-compliance was associated with treatment failure (P = 0.02). Fourteen out of the 17 (82%) evaluable paired isolates had identical DNA fingerprint patterns, whereas three pairs showed that a different strain of MAC was present at the time of treatment failure. CONCLUSIONS: Initial resistance to clarithromycin was rare during this period. However, late treatment failure associated with the emergence of clarithromycin resistance was relatively common during long-term follow-up. Most late treatment failures represented emergence of clarithromycin resistance in the initial strain.

AIDS-Related Opportunistic Infections↗

Global surveillance for antituberculosis-drug resistance, 1994-1997. World Health Organization-International Union against Tuberculosis and Lung Disease Working Group on Anti-Tuberculosis Drug Resistance Surveillance.

BACKGROUND: Drug-resistant tuberculosis threatens efforts to control the disease. This report describes the prevalence of resistance to four first-line drugs in 35 countries participating in the World Health Organization-International Union against Tuberculosis and Lung Disease Global Project on Anti-Tuberculosis Drug Resistance Surveillance between 1994 and 1997. METHODS: The data are from cross-sectional surveys and surveillance reports. Participating countries followed guidelines to ensure the use of representative samples, accurate histories of treatment, standardized laboratory methods, and common definitions. A network of reference laboratories provided quality assurance. The median number of patients studied in each country or region was 555 (range, 59 to 14,344). RESULTS: Among patients with no prior treatment, a median of 9.9 percent of Mycobacterium tuberculosis strains were resistant to at least one drug (range, 2 to 41 percent); resistance to isoniazid (7.3 percent) or streptomycin (6.5 percent) was more common than resistance to rifampin (1.8 percent) or ethambutol (1.0 percent). The prevalence of primary multidrug resistance was 1.4 percent (range, 0 to 14.4 percent). Among patients with histories of treatment for one month or more [corrected], the prevalence of resistance to any of the four drugs was 36.0 percent (range, 5.3 to 100 percent), and the prevalence of multidrug resistance was 13 percent (range, 0 to 54 percent). The overall prevalences were 12.6 percent for resistance to any of the four drugs [corrected] (range, 2.3 to 42.4 percent) and 2.2 percent for multidrug resistance (range, 0 to 22.1 percent). Particularly high prevalences of multidrug resistance were found in the former Soviet Union, Asia, the Dominican Republic, and Argentina. CONCLUSIONS: Resistance to antituberculosis drugs was found in all 35 countries and regions surveyed, suggesting that it is a global problem.

Antitubercular Agents↗

Septic shock from Mycobacterium tuberculosis after therapy for Pneumocystis carinii.

Septic shock resulting from Mycobacterium tuberculosis (TB) occurs only rarely, even among patients infected with human immunodeficiency virus. We report a case of fulminant TB sepsis in the setting of human immunodeficiency virus infection. This case illustrates the hazards of corticosteroid use as a part of empirical treatment of Pneumocystis carinii pneumonia, as well as the unique appearance of TB on chest x-ray films.

AIDS-Related Opportunistic Infections↗

Size and duration of zidovudine benefit in 1003 HIV-infected patients: U.S. Army, Navy, and Air Force natural history data. Military Medical Consortium for Applied Retroviral Research.

OBJECTIVES: The study's objectives were to determine the size and duration of benefits of early versus delayed versus late treatment with zidovudine (ZDV) on disease progression and mortality in HIV-infected patients, and whether patients rapidly progressing before ZDV treatment had a different outcome from those not rapidly progressing before ZDV. DESIGN: The design was an inception cohort of 1003 HIV-infected patients. One hundred and seventy-four of the 1003 patients were treated before CD4 counts fell to <400 x 10(9)/L, ("early treatment"); 183 of 1003 patients were treated after CD4 counts fell to <400 x 10(9)/L but before clinical disease developed ("delayed treatment"); and 646 of the 1003 patients had either been treated after clinical disease developed or had not been treated at all by the end of follow-up ("late treatment"). Outcomes were progression to clinical HIV disease and mortality. RESULTS: The relative risk (RR) of progression for early versus delayed treatment was 0.58 (p < .03), and durability of ZDV benefits on progression was estimated at no more than 2.0 years; however, this estimate had wide confidence intervals. The RR of progression for delayed versus late treatment was 0.54 p < .0001, and durability of ZDV benefits was estimated at 1.74 years; this estimate had narrow confidence intervals. Survival was better for the early versus delayed treatment (RR = 0.55), but this difference was not statistically significant. In the subgroup of patients with more rapid CD4 decline prior to ZDV therapy, significant benefits on progression were observed for early versus delayed ZDV therapy (RR = 0.42, p = .02) and delayed versus late ZDV therapy (RR = 0.51; p = .0004). Duration of benefit was estimated to be 4.5 years (early versus delayed) and 1.7 years (delayed versus late). For patients with less rapid pre-ZDV decline in CD4 levels, a significant progression benefit was observed for delayed versus late therapy (RR = 0.50; p = .02). Duration of benefit in this subgroup was estimated to be 1.8 years. No significant benefit was found for early versus delayed treatment (RR = 1.12) in the less rapid pre-ZDV CD4 cell decline subgroup. CONCLUSIONS: Early treatment compared with delayed treatment was associated with a sizable reduction in HIV progression, but the duration of benefits was estimated to last only about 2 years. Delayed treatment compared with late treatment with ZDV was associated with substantial reduction of progression, but this reduction was also clearly limited in duration. Benefits on progression and mortality for the early treatment group were heavily dependent on the pre-ZDV CD4 slope. In the subgroup of patients with the most rapid pre-ZDV CD4 cell declines, the duration of benefit was much longer, possibly as long as 4 years.

Adult↗