Efficacy of azithromycin in prevention of Pneumocystis carinii pneumonia: a randomised trial. California Collaborative Treatment Group

Pneumocystis Pneumonia Mimicking Atypical Pneumonia in a Patient With Human Immunodeficiency Virus Infection

We report a case of pneumocystis pneumonia (PCP) that mimicked atypical pneumonia in a patient with human immunodeficiency virus (HIV) infection. A 44-year-old Japanese man with persistent fever and dyspnea for a month was diagnosed with atypical pneumonia because of bilateral ground-glass opacities on chest computed tomography (CT). Ground-glass opacities on chest CT diminished with three days treatment of azithromycin; however, his symptoms were persistent. Final diagnosis of HIV and PCP infection was eventually confirmed. Physicians should consider the possibility of PCP even when pulmonary manifestations resolve with azithromycin in patients with HIV infection.

Effect of Mass Treatment with Azithromycin on Causes of Death in Children in Malawi: Secondary Analysis from the MORDOR Trial

Recent evidence indicates mass drug administration with azithromycin may reduce child mortality. This study uses verbal autopsy (VA) to investigate the causes of individual deaths during the Macrolides Oraux pour Réduire les Décès avec un Oeil sur la Résistance (MORDOR) trial in Malawi. Cluster randomization was performed as part of MORDOR. Biannual household visits were conducted to distribute azithromycin or placebo to children aged 1–59 months and update the census to identify deaths for VA. MORDOR was not powered to investigate mortality effects at individual sites, but the available evidence is presented here for hypothesis generation regarding the mechanism through which azithromycin may reduce child mortality. Automated VA analysis was performed to infer the likely cause of death using two major analysis programs, InterVA and SmartVA. A total of 334 communities were randomized to azithromycin or placebo, with more than 130,000 person-years of follow-up. During the study, there were 1,184 deaths, of which 1,131 were followed up with VA. Mortality was 9% lower in azithromycin-treated communities than in placebo communities (rate ratio 0.91 [95% CI: 0.79–1.05]; P = 0.20). The intention-to-treat analysis by cause using InterVA suggested fewer HIV/AIDS deaths in azithromycin-treated communities (rate ratio 0.70 [95% CI: 0.50–0.97]; P = 0.03) and fewer pneumonia deaths (rate ratio 0.82 [95% CI: 0.60–1.12]; P = 0.22). The use of the SmartVA algorithm suggested fewer diarrhea deaths (rate ratio 0.71 [95% CI: 0.51–1.00]; P = 0.05) and fewer pneumonia deaths (rate ratio 0.58 [95% CI: 0.33–1.00]; P = 0.05). Although this study is not able to provide strong evidence, the data suggest that the mortality reduction during MORDOR in Malawi may have been due to effects on pneumonia and diarrhea or HIV/AIDS mortality.

Effect of Macrolide Prophylactic Therapy on AIDS-Defining Conditions and HIV-Associated Mortality

BACKGROUND

Mycobacterium avium complex prophylaxis is recommended for patients with advanced HIV infection. With the decrease in incidence of disseminated Mycobacterium avium complex infection and the availability of antiretroviral therapy (ART), the benefits of macrolide prophylaxis were investigated. This study examined the impact of macrolide prophylaxis on AIDS-defining conditions and HIV-associated mortality in a cohort of HIV-infected patients on ART.

METHODS

Patients from TREAT Asia HIV Observational Database (September 2015 data transfer) aged 18 years and older with a CD4 count <50 cells/mm at ART initiation were included. The effect of macrolide prophylaxis on HIV-associated mortality or AIDS-defining conditions (as a combined outcome) and HIV-associated mortality alone were evaluated using competing risk regression. Sensitivity analysis was conducted in patients with a CD4 <100 cells/mm at ART initiation.

RESULTS

Of 1345 eligible patients, 10.6% received macrolide prophylaxis. The rate of the combined outcome was 7.35 [95% confidence interval (CI): 6.04 to 8.95] per 100 patient-years, whereas the rate of HIV-associated mortality was 3.14 (95% CI: 2.35 to 4.19) per 100 patient-years. Macrolide use was associated with a significantly decreased risk of HIV-associated mortality (hazard ratio 0.10, 95% CI: 0.01 to 0.80, P = 0.031) but not with the combined outcome (hazard ratio 0.86, 95% CI: 0.32 to 2.229, P = 0.764). Sensitivity analyses showed consistent results among patients with a CD4 <100 cells/mm at ART initiation.

CONCLUSIONS

Macrolide prophylaxis is associated with improved survival among Asian HIV-infected patients with low CD4 cell counts and on ART. This study suggests the increased usage and coverage of macrolide prophylaxis among people living with HIV in Asia.

[Pneumocystis jirovecii pneumonia-an opportunistic infection undergoing change]

Pneumocystis jirovecii pneumonia (PcP) has for many years been reported mostly in human immunodeficiency virus-infected patients. Increasingly, it also affects other immunocompromised patients, e.g. after organ or allogeneic stem cell/bone marrow transplantation, patients with hematologic malignancies or autoimmune diseases. The diagnosis of PcP relies on a critical evaluation of clinical symptoms, risk factors, radiologic features and microbiological tests. High dose cotrimoxazole is the most effective therapeutic option. Rapid initiation is essential, since mortality is especially high in patients admitted to intensive care with respiratory failure. This article reviews the current epidemiology of PcP and highlights the diagnostic and therapeutic options. Recommendations for primary and secondary prophylaxis are summarized.

Increased prevalence of Pneumocystis jirovecii colonisation in acute pulmonary exacerbations of cystic fibrosis

OBJECTIVES

This study examined the prevalence of Pneumocystis jirovecii in the sputum of adults with cystic fibrosis during clinical stability and acute pulmonary exacerbation.

METHODS

This was a prospective, longitudinal observational study of patients attending the Manchester Adult Cystic Fibrosis Centre. Sputum samples were analysed for P. jirovecii DNA using PCR at enrolment and up to 5 follow-up visits. Patients were classified as stable or exacerbating using a modified Fuch's pulmonary exacerbation score.

RESULTS

226 samples were tested from 111 patients. P. jirovecii was more likely to be detected in samples at acute pulmonary exacerbation (7/76 (9.2%)) compared with stable visits (3/150 (2%)), p = 0.03. P. jirovecii was detected less frequently if patients had received co-trimoxazole within 3 months of sample collection (0% versus 29.7%, p = 0.03).

CONCLUSIONS

Prevalence of P. jirovecii in stable patients is low, but P. jirovecii is detected in approximately 1 in 10 patients experiencing an acute pulmonary exacerbation.

[Medicinal prophylaxis during intensified immunosuppression in children and adolescents : part 2]

The goal of modern antirheumatic therapy is to achieve an optimized disease control. This is individually achieved by an intensified immunosuppression (IS) frequently combining different immunosuppressive agents. Intensified IS should be accompanied by a standardized protocol to monitor immunological changes in the patient. This should include checklists (see Part 1 Screening during intensified IS in children and adolescents). An individual risk stratification according to the planned IS allows a prediction of infectious disease risks for the patient and, thus, individual infection prophylaxis. In addition, standardized management of patients with fever while receiving intensified IS may prevent further complications.

Dapsone-induced methemoglobinemia in renal transplant recipients: more prevalent than previously thought

BACKGROUND

After an outbreak of Pneumocystis pneumonia (PCP) in our nephrology unit, dapsone was used as the second-line chemoprophylactic agent. Dapsone is the most common cause of drug-induced methemoglobinemia (MHb). Its prevalence is poorly described in the renal transplant population. Because dapsone is excreted by the kidneys, we hypothesized that the rate of MHb in these patients would be higher than previously reported. We aimed to describe the demographics, risk factors, and presenting features of MHb in these renal transplant patients.

METHODS

Twenty-six transplant recipients commenced on dapsone for chemoprophylaxis against PCP from February to September 2011. All patients had normal glucose-6-phosphate dehydrogenase levels before treatment. Characteristics of patients with MHb were compared with those of the rest of the cohort to determine potential risk factors.

RESULTS

Twelve (46%) patients developed MHb (levels 6.4 ± 4.1%). Six (50%) of the patients with MHb were asymptomatic on presentation. Cases had a mean drop in hemoglobin of 19 ± 7%. MHb led to five admissions (median length of stay 5 days, range 1-10 days). MHb level showed a strong correlation with the length of stay (correlation coefficient 0.762, P = 0.002).

CONCLUSION

This is the highest reported prevalence of MHb, to our knowledge, in patients receiving dapsone, and its use led to significant hospitalization in this population. This study raises concerns about the use of dapsone as chemoprophylaxis in renal transplant recipients.

Inhaled azithromycin therapy

The treatment of pulmonary infectious diseases with pharmaceutical aerosols is an attractive option considering the accessibility of the lungs for topical drug delivery. Aerosols have been targeted to the lungs for the treatment of asthma with great success. Current therapies for other diseases, including Pseudomonas aeruginosa, Pneumocystis jirovecii (formerly Pneumocystis carinii), and mycobacterial infections, remain suboptimal due to the efficacy/safety profile. This may be improved by aerosol targeted pulmonary drug delivery. Azithromycin is a broad spectrum antibiotic that acts by inhibiting protein synthesis. It is associated with side effects that might be avoided by aerosol delivery to the lungs. In the present study three concentrations of azithromycin (10, 50, and 100 mg/mL) were delivered from three nebulizers (Acorn II, Updraft, and LC Plus) operated at 8 L/min. Particles size analyses were conducted by inertial impaction and laser diffraction. In addition, emitted doses were determined. A linear proportionality existed across the concentration range between nominal dose and both fine particle dose/fraction and emitted dose, with R2 > 0.999 in all cases. The mass median aerodynamic diameter increased from 1.4 to 1.9 microm between 10 and 100 mg/mL of azithromycin solution concentration for the Acorn II. The particle size distributions were not all log-normally distributed. The median particle size delivered from the devices was largest for the Updraft (2.8 microm) and smallest for the Acorn II (1.9 microm) for 100 mg/mL azithromycin solution concentrations. The efficiencies of small particle delivery (%<4.7 microm) were as follows, LC Plus = Acorn II (85%) > UpDraft (75%). However, the emitted dose from the LC Plus (55 mg/min) was higher than the Acorn II (31 mg/min) to maximize lung exposure to the aerosol, small median diameters and broad particle size distributions would be most effective. This study demonstrates that the dose delivered to the lungs will be maximized, under the current operating conditions by adopting the LC Plus, and high (100 mg/mL) azithromycin concentrations.

Prevalence of colonisation and genotypic characterisation of Pneumocystis jirovecii among cystic fibrosis patients in Spain

Pneumocystis jirovecii colonisation may occur among cystic fibrosis (CF) patients because of their underlying pulmonary disease. A wide epidemiological analysis was performed among CF patients from Spain to assess the prevalence of P. jirovecii colonisation and the distribution of different genotypes. P. jirovecii was identified by nested PCR targeting the mitochondrial large-subunit rRNA gene from sputum samples or oropharyngeal washes. The genotype was determined by direct sequencing. The prevalence of P. jirovecii colonisation among 88 consecutive CF patients was 21.5%. The polymorphisms identified were 85C/248C (45.4%), 85T/248C (27.2%) and 85A/248C (18.1%); in one case, a mix of genotypes was found. Colonisation was more frequent in subjects aged < 18 years (25.5% vs. 15.1%). Among the patients studied, 20.8% received treatment with azithromycin; all of these patients were colonised with P. jirovecii, but none developed Pneumocystis pneumonia (PcP) during a 1-year follow-up period. Concordance in the colonisation status of siblings suggested a common source of infection or person-to-person transmission.

Mycobacterium avium complex in patients with HIV infection in the era of highly active antiretroviral therapy

Disseminated Mycobacterium avium complex (MAC) infection is a common complication of late-stage HIV-1 infection. Since the advent of highly active antiretroviral therapy (HAART), the rate of MAC infection has declined substantially, but patients with low CD4 cell counts remain at risk. Among patients in the Johns Hopkins cohort with advanced HIV disease, the proportion developing MAC has fallen from 16% before 1996 to 4% after 1996, with a current rate of less than 1% per year. Factors associated with developing MAC include younger age, no use of HAART, and enrollment before 1996. Prophylaxis with azithromycin or clarithromycin is recommended for all patients with CD4 counts less than 50 cells/mL. Optimum treatment for disseminated MAC includes clarithromycin and ethambutol, and another investigation suggests that the addition of rifabutin might reduce mortality. Both prophylaxis and treatment of disseminated MAC can be discontinued in patients who have responded to HAART, and specific guidelines for withdrawing treatment have been published. Although HAART has altered the frequency and outcome of MAC infection, it remains an important complication of AIDS.

Disseminated mycobacterium avium-intracellulare complex (MAC) infection in the era of effective antiretroviral therapy: is prophylaxis still indicated?

Before highly active antiretroviral therapies (HAART) were available for the treatment of persons with HIV infection, disseminated Mycobacterium avium-intracellulare complex (MAC) infection was one of the most common opportunistic infections that affected people living with AIDS. Routine use of chemoprophylaxis with a macrolide has been advocated in guidelines for the treatment of HIV-infected individuals if they have a circulating CD4+ cell count of < or =50 cells/microL. In addition, lifelong prophylaxis for disease recurrence has been recommended for those with a history of disseminated MAC infection. The introduction of HAART has resulted in a remarkable decline in the incidence of opportunistic infections and death among persons living with AIDS. Considerable reconstitution of functional immune responses against opportunistic infections can be achieved with HAART. In the case of infection with MAC, there has been a substantial reduction in the incidence of disseminated infections in the HAART era, even in countries where the use of MAC prophylaxis was never widely accepted. Moreover, the clinical picture of MAC infections in patients treated with potent antiretroviral therapies has shifted from a disseminated disease with bacteraemia to a localised infection, presenting most often with lymphadenopathy and osteomyelitis. Data from several recently conducted randomised, double-blind, placebo-controlled trials led to the current practice of discontinuing primary and secondary prophylaxis against disseminated MAC infections at stable CD4+ cell counts >100 cells/microL. These recommendations are still conservative as primary or secondary disseminated MAC infections are only rarely seen in patients who respond to HAART, despite treatment initiation at very low CD4+ cell counts. Potential adverse effects of macrolide therapy and drug interactions with antiretrovirals also metabolised via the cytochrome P450 enzyme system must be critically weighed against the marginal benefit that MAC prophylaxis may provide in addition to treatment with HAART. These authors feel that, unless patients who initiate HAART at low CD4+ cell counts do not respond to HIV-treatment, routine MAC prophylaxis should not be recommended. Nevertheless, the patient population for whom MAC prophylaxis may still be indicated in the era of HAART needs to be identified in prospectively designed clinical trials.

Influence of daily low-dose 14-membered-ring macrolide therapy on Helicobacter pylori infection in patients with chronic inflammatory disease of the airway

Our aim was to evaluate the effects of eradication and the incidence of secondary resistance by long-term low-dose daily 14-membered-ring macrolide therapy on Helicobacter pylori ( H. pylori) infection in patients with chronic lower respiratory tract inflammatory disease. In a retrospective analysis, we studied the seroprevalence of H. pylori IgG in 90 patients with inflammation of the lower respiratory tract (68 had been treated with macrolide and 22 served as controls). Then, in a prospective analysis, we evaluated the eradication effect of macrolide therapy by the decline of IgG values and the (13)C-urea breath test. Only long-term macrolide use significantly affected the seroprevalence of H. pylori IgG. However, macrolide therapy did not reduce the H. pylori IgG values in 24 patients and did not eradicate H. pylori in (13)C-urea breath tests. Chemosensitivity testing was performed on three H. pylori strains obtained by gastric biopsy from patients in whom the disease could not be eradicated. Only one strain demonstrated a resistant character. Daily long-term low-dose 14-membered-ring macrolide therapy for patients with lower respiratory inflammatory disease may not be sufficient to eradicate H. pylori, but some strains do not acquire a resistant nature.

Pharmacokinetic and pharmacodynamic issues in the treatment of mycobacterial infections

The therapy of mycobacterial infections is challenging for a number of reasons. Because mycobacteria are not susceptible to many classes of antibacterial agents, treatment typically requires the use of antimicrobial drugs that are not commonly used and may have small therapeutic windows. For many species, procedures for drug susceptibility testing and optimal treatment regimens have yet to be defined. Finally, because mycobacteria are generally slow to succumb to antimicrobial agents, therapy must be given with multiple drugs for prolonged periods of time, making it necessary to monitor for drug toxicity, drug interactions, and patient nonadherence. Better understanding of the pharmacokinetics and pharmacodynamics of antimycobacterial agents should improve the therapy of mycobacterial infections. Using current treatment strategies for tuberculosis and Mycobacterium avium complex infections as examples, this review highlights basic pharmacokinetic and pharmacodynamic principles and the rationale for combination chemotherapy that should also be applicable to other mycobacterial infections.

Pneumocystis jiroveci Pneumonia in Adult Patients with AIDS

Pneumocystis jiroveci (P. carinii) is an opportunistic pathogen that has gained particular prominence since the onset of the AIDS epidemic. Among several important advances in diagnosis and management, appropriately targeting chemoprophylaxis to HIV-infected patients at high clinical risk for P. jiroveci pneumonia and the introduction of effective combination anti-retroviral therapy (including highly active antiretroviral therapy [HAART]) have contributed to the reduced incidence of P. jiroveci pneumonia. Despite the success of these clinical interventions, P. jiroveci pneumonia remains the most common opportunistic pneumonia and the most common life-threatening infectious complication in HIV-infected patients. Trimethoprim/sulfamethoxazole (cotrimoxazole) remains the first-line agent for effective therapy and chemoprophylaxis, and corticosteroids represent an important adjunctive agent in the treatment of moderate-to-severe P. jiroveci pneumonia. However, problems of chemoprophylaxis and treatment failures, high rates of adverse drug reactions and drug intolerance to first-line antimicrobials, high rates of relapse or recurrence with second-line agents, and newer concerns about the development of P. jiroveci drug resistance represent formidable challenges to the management and treatment of AIDS-related P. jiroveci pneumonia. With the expanding global problem of HIV infection, the intolerance or unavailability of HAART to many individuals and limited access to healthcare for HIV-infected patients, P. jiroveci pneumonia will remain a major worldwide problem in the HIV-infected population. New drugs under development as anti-Pneumocystis agents such as echinocandins and pneumocandins, which inhibit beta-glucan synthesis, or sordarins, which inhibit fungal protein synthesis, show promise as effective agents. Continued basic research into the biology and genetics of P. jiroveci and host defense response to P. jiroveci will allow the development of newer antimicrobials and immunomodulatory therapeutic agents to more effectively treat life-threatening pneumonia caused by this organism.

Azithromycin prophylaxis for Mycobacterium avium complex during the era of highly active antiretroviral therapy: evaluation of a provincial program

Mycobacterium avium complex (MAC) disease was evaluated in a provincial program of azithromycin prophylaxis. Highly active antiretroviral therapy (HAART) was prescribed to 383 (65%) of 587 patients eligible for MAC prophylaxis (CD4 <75 cells/mm3). By use of an intent-to-treat analysis, MAC disease was observed in 21 of 271 patients who did not receive prophylaxis (incidence rate, 8 events per 100 person-years). MAC events occurred in 10 of 316 patients who received azithromycin (2.37 events per 100 person-years). Localized lymphadenitis compatible with immune reconstitution disease accounted for 23% of all MAC events, in contrast to studies in the pre-HAART era, where almost all cases were disseminated. None of the MAC isolates from the 10 prophylaxis failures were resistant to azithromycin. Azithromycin appeared to be protective against disseminated MAC in patients who were either unresponsive or nonadherent to HAART, but it did not prevent the development of immune reconstitution disease due to MAC.

Erythromycin and common cold in COPD

STUDY OBJECTIVES

To investigate whether erythromycin therapy lowers the frequency of the common cold and subsequent exacerbation in patients with COPD.

DESIGN

Prospective, randomized, controlled, but not blinded, trial.

PATIENTS

One hundred nine patients with COPD were enrolled into the study. Patients were randomly assigned to erythromycin therapy or to no active treatment in September 1997. Patients then were observed for 12 months, starting in October, during which time the risk and frequency of catching common colds and COPD exacerbations were investigated. Fifty-five patients received erythromycin at study entry (erythromycin group). The remaining 54 patients received no active treatment (control group).

MEASUREMENTS AND RESULTS

The mean (+/- SE) number of common colds for 12 months was significantly lower in the erythromycin group than in the control group (1.24 +/- 0.07 vs 4.54 +/- 0.02, respectively, per person; p = 0.0002). Forty-one patients (76%) in the control group experienced common colds more than once, compared to 7 patients (13%) in the erythromycin group. The relative risk of developing two or more common colds in the control group compared with that in the erythromycin group was 9.26 (95% confidence interval [CI], 3.92 to 31.74; p = 0.0001). Thirty patients (56%) in the control group and 6 patients (11%) in the erythromycin group had one or more exacerbations. The relative risk of experiencing an exacerbation in the control group compared with that in the erythromycin group was 4.71 (95% CI, 1.53 to 14.5; p = 0.007). Significantly more patients were hospitalized due to exacerbations in the control group than in the erythromycin group (p = 0.0007).

CONCLUSION

Erythromycin therapy has beneficial effects on the prevention of exacerbations in COPD patients.

Impact of prophylaxis for Mycobacterium avium complex on bacterial infections in patients with advanced human immunodeficiency virus disease

The epidemiology and natural history of bacterial infections among ambulatory patients with advanced human immunodeficiency virus (HIV) disease has not been well described. In this prospective study, 394 subjects were enrolled and followed at 8-week intervals for a median of 21 months. During follow-up, 164 (42%) of 394 patients developed at least 1 bacterial infection. The most common infections were sinusitis, bacterial pneumonia, skin and soft tissue infection, and bronchitis. Serious bacterial infections (defined as bacterial pneumonia, bacteremia, or deep visceral abscess) were reported by 56 subjects (14%). Female sex, age of <40 years, and Karnofsky score of < or =80 were independent risk factors for bacterial infections. Prophylaxis with clarithromycin, trimethoprim and sulfamethoxazole, or both had significant protective effect. The occurrence of any confirmed bacterial infection was associated with a significantly increased risk of mortality. This study documents that bacterial infections are common among patients with advanced HIV disease, especially among women.

Lack of an effect of azithromycin on the disposition of zidovudine and dideoxyinosine in HIV-infected patients

Two studies were conducted in HIV-infected subjects to assess the potential for azithromycin to interact with zidovudine and dideoxyinosine. Both studies used 12 subjects. The zidovudine study dosed subjects with 1200 mg/day of azithromycin (n = 7) (later changed to 600 mg/day [n = 5]) for Days 8 to 21 of a 21-day course of 100 mg, five times/day of zidovudine. Subjects treated with 200 mg of dideoxyinosine twice daily for 21 days received 1200 mg of azithromycin or an equivalent amount of placebo/day for Days 8 to 21. Antiretroviral plasma and urine sampling were conducted on Days 1, 7, and 21 for zidovudine and on Days 7 and 21 for dideoxyinosine. Peripheral mononuclear cells were also collected for quantitation of phosphorylated zidovudine. Azithromycin had no significant impact on the Cmax and AUC of zidovudine, although it significantly decreased the zidovudine tmax by 44% and increased the intracellular exposure to phosphorylated zidovudine by 110%. Azithromycin had no significant effect on dideoxyinosine pharmacokinetics. Based on the results of these studies, it is concluded that azithromycin may be safely coadministered with both zidovudine and dideoxyinosine.

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.