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Biomedical subjects

M A Jacobson

Publications and source records attributed to M A Jacobson.

At least 91 records · Page 5Linked to original sources

Pharmacokinetics of concomitantly administered foscarnet and zidovudine for treatment of human immunodeficiency virus infection (AIDS Clinical Trials Group protocol 053).

Foscarnet and zidovudine (ZDV) pharmacokinetic parameters were not altered in five patients receiving 14 days of concomitant therapy. Foscarnet clearance in plasma averaged (+/- standard deviation) 0.16 +/- 0.03 and 0.13 +/- 0.05 liter/h/kg of body weight in the absence and presence of ZDV. ZDV parameters were also not significantly altered, with a mean (+/- standard deviation) oral clearance of 2.7 +/- 1.0 and 2.6 +/- 0.8 liter/h/kg for the 2 study days, respectively.

Acquired Immunodeficiency Syndrome↗

Drug hypersensitivity reactions and human immunodeficiency virus disease.

Drug hypersensitivity reactions are often observed by clinicians treating patients infected with the human immunodeficiency virus (HIV). For certain drugs, the incidence of these reactions appears to be higher than previously reported in the general population. The best example is trimethoprim-sulfamethoxazole, associated with rash, fever, hematologic disturbances, transaminase elevation, and, less frequently, more severe reactions, including Stevens-Johnson syndrome, toxic epidermal necrolysis, and anaphylactic-like reactions. Other sulfa congeners, pentamidine, antituberculosis regimens containing isoniazid and rifampin, amoxicillin-clavulanate, clindamycin, and thalidomide also have been associated with an increased incidence of adverse reactions, some of which could involve allergic mechanisms. Effective dosage and management strategies are needed to prevent or ameliorate hypersensitivity reactions when they occur.

Drug Hypersensitivity↗

Review of the toxicities of foscarnet.

The primary dose-limiting adverse effects associated with foscarnet treatment of cytomegalovirus retinitis in patients with AIDS are renal impairment and ionized hypocalcemia. Dose-limiting renal impairment, consisting of significant alterations in serum creatinine levels or creatinine clearance or acute renal failure, has been observed in 10-20% of AIDS patients receiving foscarnet via intermittent i.v. infusion. Nephrotoxicity can be minimized by adjusting dosage according to creatinine clearance and by ensuring that adequate hydration is provided throughout foscarnet therapy. Transient decreases in serum or plasma ionized calcium levels appear to occur in all patients during foscarnet infusion, with these decreases being observed in the absence of changes in total calcium levels. Hypocalcemia produces mild symptoms in some patients and may play a role in unexplained cases of arrhythmia or seizure. Careful attention should be given to levels of total calcium and other minerals during foscarnet treatment, and the occurrence of symptomatic hypocalcemia should prompt evaluation of ionized calcium concentrations and foscarnet dose reduction. Another potentially treatment-limiting effect attributed to foscarnet is penile ulceration, which appears to result from exposure of the glans penis to unchanged foscarnet in the urine.

Antiviral Agents↗

Early predictors of survival in symptomatic HIV-infected persons treated with high-dose zidovudine.

The survival times of 246 patients treated with high-dose zidovudine beginning in 1986 were obtained through November 1988. We analyzed clinical and laboratory predictors of survival as measured before initiation of therapy and during the first 32 weeks of therapy. In a multivariate proportional-hazards model, we found significant independent predictive abilities for four pretherapy measurements (AIDS versus ARC diagnosis, Karnofsky performance score, age, and hemoglobin) and four measurements made during therapy (change in log CD4 lymphocyte count from pretherapy to week 24, CD8 lymphocyte count at week 24, rate of decline of hemoglobin over the first 3 months of therapy, and rate of decline in white blood count over the first 6 months of therapy). The presence of three predictors measured during therapy that are statistically significant when controlled for changes in CD4 count suggests that the use of other measures in addition to CD4 counts may substantially improve the prediction of long-term survival based on early response of surrogate markers to therapy.

Drug Administration Schedule↗

Surrogate markers for survival in patients with AIDS and AIDS related complex treated with zidovudine.

OBJECTIVE: To determine whether early effects of zidovudine treatment on CD4+ lymphocyte count and concentrations of beta 2 microglobulin, neopterin, or HIV p24 antigen or antibody are correlated with survival in patients with AIDS or AIDS related complex. DESIGN: Retrospective study of changes in laboratory markers and survival. SETTING: Multicentre trial at university hospital clinics. SUBJECTS: 90 Patients with AIDS or AIDS related complex. INTERVENTION: Patients started zidovudine 200 mg orally every four hours. Fifty six of the patients died a median 17 months after starting zidovudine; the remaining 34 patients were followed up for a median 25.5 months. MAIN OUTCOME MEASURES: Changes in CD4+ lymphocyte count and serum concentrations of p24 antigen and antibody, beta 2 microglobulin, and neopterin; survival of the patient. RESULTS: The pretreatment characteristics that independently predicted poor survival were determined using a multivariate proportional hazards model: a diagnosis of AIDS (v AIDS related complex), age over 45 years, and the logarithm of serum neopterin concentration. When these baseline characteristics were controlled for the logarithm of CD4+ lymphocyte count at weeks 8-12 of treatment (p = 0.007) and an increase in serum beta 2 microglobulin concentration at weeks 8-12 (p = 0.05) also independently correlated with survival. In the 38 patients with a better pretreatment prognosis, 24 month survival estimated by the product-limit method was 88% for those with a good response on both surrogate markers during early treatment compared with only 50% for those with a poor response on either marker. In the 38 with a worse pretreatment prognosis, 24 month survival was estimated to be 49% for those with a good response on both surrogate markers compared with only 18% for those with a poor response on either. CONCLUSION: These data suggest that CD4+ lymphocyte count at 8-12 weeks and, perhaps, change in serum beta 2 microglobulin concentration could be surrogate end points for clinical outcome in trials of antiretroviral drugs for patients with HIV disease.

AIDS-Related Complex↗

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.

Acquired Immunodeficiency Syndrome↗

Foscarnet therapy for ganciclovir-resistant cytomegalovirus retinitis in patients with AIDS.

Infections caused by cytomegalovirus (CMV) resistant in vitro to ganciclovir, defined as requiring greater than 6 mumols of ganciclovir for ED50 have developed in some AIDS patients with progressive CMV retinitis despite chronic ganciclovir therapy. Two such patients (CMV isolates ED50, 9.5-14.5 mumols) were treated with foscarnet, an antiviral pyrophosphate analogue to which both patients' isolates demonstrated in vitro susceptibility (ED50, less than or equal to 300 mumols). Each patient had documented retinitis progression, at 2- and 1- to 5-week intervals, respectively, despite high-dose intravenous ganciclovir therapy. Both patients responded to foscarnet therapy with cessation of viral shedding in urine and blood. After foscarnet therapy was started, retinitis stabilized in the two patients for 12 and 25 weeks, respectively, before progression recurred. Therefore, foscarnet may be effective in immunocompromised patients with rapidly progressive CMV retinitis whose CMV isolates have developed in vitro resistance to ganciclovir.

Acquired Immunodeficiency Syndrome↗

Decreased serum dehydroepiandrosterone is associated with an increased progression of human immunodeficiency virus infection in men with CD4 cell counts of 200-499.

Dehydroepiandrosterone (DHEA) and its interconvertible sulfate derivative (DHEA-S) are human androgenic steroids that have been reported to inhibit viral expression and have been associated with a decreased risk of cancer. The relationship between serum DHEA and DHEA-S levels and subsequent progression to AIDS was investigated in a sample of human immunodeficiency virus (HIV)-infected men from the San Francisco Men's Health Study followed prospectively since 1984. Among 108 men seropositive for HIV at study entry and with CD4 lymphocyte counts of 200-499 microliters 24 months later, serum DHEA levels below the lower limit of normal (less than 180 ng/dl) at this later date were predictive of subsequent progression to AIDS (relative hazard = 2.34; 95% confidence interval = 1.18-4.63; P = .01) after controlling for hematocrit, age, and log absolute CD4 cell number in a Cox proportional hazards model. This is the first large prospective cohort in which an endocrinologic variable has been observed to independently predict progression to AIDS. These observations, in addition to recent in vitro data, suggest that DHEA might have a protective effect in HIV infection.

Adult↗

Natural history of disseminated Mycobacterium avium complex infection in AIDS.

This study sought to better characterize the natural history of AIDS-associated disseminated Mycobacterium avium complex (MAC) infection. Towards that end two retrospective studies were done: a case-control survival study and a MAC respiratory colonization study. Among 137 consecutive patients who had a sterile body site cultured for mycobacteria within 3 months of their first AIDS-defining episode of Pneumocystis carinii pneumonia, median survival was significantly shorter in those with disseminated MAC infection (107 days; 95% confidence interval [CI] 55-179) than those with negative cultures (275 days; 95% CI 230-318; P less than .01), even after controlling for age, absolute lymphocyte count, and hemoglobin concentration. Among 34 patients with AIDS and respiratory MAC colonization, 22 later developed disseminated infection (65% predictive value for subsequent MAC dissemination). Disseminated MAC infection was associated with significantly shorter survival for patients with AIDS, and the presence of MAC in respiratory specimens has substantial predictive value for subsequent disseminated infection.

Acquired Immunodeficiency Syndrome↗

Survival of patients with AIDS and cytomegalovirus disease treated with ganciclovir or foscarnet.

We reviewed the hospital charts of 168 patients with AIDS and cytomegalovirus (CMV) disease diagnosed at San Francisco General Hospital between July 1985 and October 1989. One hundred and thirty-three patients had CMV retinitis, 33 had CMV gastrointestinal disease, and two had CMV lung disease. We found a trend towards longer survival from time of CMV disease diagnosis in patients with more recent dates of diagnosis. The median survival of patients diagnosed with CMV disease prior to 30 September 1987 was 4 months, compared with 9 months for patients diagnosed after 30 September 1987 (P = 0.001). The relative hazard of death for patients with CMV retinitis who were initially treated with foscarnet was not significantly reduced compared to those initially treated with ganciclovir. Even after controlling for age at time of CMV diagnosis, time from index AIDS diagnosis, hemoglobin, absolute lymphocyte count, absolute neutrophil count and concurrent zidovudine therapy, the relative hazard for foscarnet-treated patients compared with ganciclovir-treated patients was 1.0 (95% confidence interval, 0.5-1.8).

Acquired Immunodeficiency Syndrome↗

Morbidity and mortality of patients with AIDS and first-episode Pneumocystis carinii pneumonia unaffected by concomitant pulmonary cytomegalovirus infection.

To determine the significance of cytomegalovirus (CMV) pulmonary coinfection with Pneumocystis carinii pneumonia in AIDS, we examined the association of long- and short-term survival and morbidity (as defined by length of hospital stay) with recovery of CMV from bronchoscopy specimens and an indirect measure of virus titer in bronchoalveolar lavage fluid (the time to develop CMV cytopathology in culture) in 111 patients diagnosed with a first episode of P. carinii pneumonia. Compared with 57 individuals from whom CMV was not isolated, the 54 individuals from whom CMV were isolated did not differ in baseline characteristics, long-term survival (213 versus 275 days, p = 0.97), acute death rate (19% in both, p = 1.0), or length of hospital stay (19.7 versus 21.1 days, p = 0.68). Also, the time to develop CMV cytopathology in culture did not correlate with acute or long-term survival. Our observations thus do not support the use of CMV-specific antiviral therapy in AIDS patients with P. carinii pneumonia who also have evidence of pulmonary CMV infection.

Acquired Immunodeficiency Syndrome↗

Foscarnet-induced hypocalcemia and effects of foscarnet on calcium metabolism.

Foscarnet (trisodium phosphonoformate), an investigational pyrophosphate analog increasingly used to treat refractory cytomegalovirus retinitis and mucocutaneous herpes simplex virus infections in immunocompromised patients, has been reported to cause abnormalities in serum calcium and phosphate, including cases of fatal hypocalcemia. To further elucidate the magnitude and mechanism of these abnormalities in humans treated with foscarnet for opportunistic herpes virus infections, we analyzed anaerobic serum specimens and 24-h urine samples before and after single and multiple doses of iv foscarnet and performed a series of in vitro experiments with normal human serum and plasma. Plasma ionized calcium concentrations acutely decreased by a mean 0.17 mmol/L in the 6 individuals who received a 90 mg/kg dose of foscarnet and by a mean 0.28 mmol/L in the 11 individuals who received a 120 mg/kg dose (P = 0.016, 90 vs. 120 mg/kg dose). Results of in vitro experiments showed a highly significant inverse linear relationship between foscarnet and ionized calcium concentrations, but no correlation between foscarnet and total calcium or phosphate concentration. Dialysis experiments suggested that the complexing of foscarnet with ionized calcium could be a cause of this ionized hypocalcemia. Physicians must be aware of this phenomenon and should measure serum ionized calcium during foscarnet therapy (preferably at the end of a foscarnet infusion) whenever neurological or cardiological abnormalities occur.

Antiviral Agents↗

Approaches to the treatment of cytomegalovirus retinitis: ganciclovir and foscarnet.

Both ganciclovir, a nucleoside analogue, and foscarnet, a pyrophosphate analogue, specifically bind cytomegalovirus (CMV) DNA polymerase and inhibit CMV replication at plasma concentrations achievable with intravenous administration. The agents have similar plasma half-lives, and both are cleared solely by the kidneys. Foscarnet has a low solubility and a high degree of ionization at physiologic pH, requiring it to be administered in higher doses and larger volumes. Both drugs are administered as an initial induction regimen followed by a long-term maintenance regimen. Among patients with the acquired immune deficiency syndrome (AIDS) who have CMV retinitis, the efficacy of long-term maintenance therapy, as measured by median time to retinitis progression, appears to be similar for the two drugs. The major toxicity of ganciclovir is myelosuppression, with dose-limiting neutropenia occurring in approximately 16% and thrombocytopenia in 5% of AIDS patients. The major toxicity of foscarnet is nephrotoxicity, with dose-limiting toxicity occurring in approximately 10-23% of patients; other effects of foscarnet include hypocalcemia, which may be associated with seizure and arrhythmia. Studies in vitro indicate an additive or synergistic inhibitory effect on CMV when these two drugs are combined, suggesting that lower-dose combination regimens or higher-dose alternating regimens may result in greater efficacy with less toxicity than with either drug alone.

Antiviral Agents↗

Cytomegalovirus esophagitis in patients with AIDS. A clinical, endoscopic, and pathologic correlation.

OBJECTIVE: To examine the clinical presentation, endoscopic features, laboratory diagnosis, and outcome of cytomegalovirus esophagitis in patients with the acquired immunodeficiency syndrome (AIDS). DESIGN: Retrospective review of endoscopy records and esophageal biopsy material from patients with AIDS during the 24-month period from 1986 to 1988. SETTING: Urban medical center, central receiving county hospital. PARTICIPANTS: Sixteen inpatients or outpatients seen by gastroenterology consultants at a single hospital. INTERVENTIONS: Endoscopy with multiple mucosal biopsies and viral culture of all esophageal mucosal lesions. Proven or suspected cyclomegalovirus disease was verified in patients using immunohistochemical antibody staining of mucosal biopsy specimens. MEASUREMENTS AND MAIN RESULTS: Odynophagia was the most prominent esophageal symptom, seen in 14 of 16 patients with cytomegalovirus esophagitis confirmed by immunohistochemical staining. Ulcerations of the esophagus were identified in all but 1 patient and typically appeared as large, solitary, shallow lesions. Routine hematoxylin and eosin staining of esophageal mucosal and submucosal specimens showed intranuclear inclusions in all patients, whereas cytomegalovirus culture was positive in only 8 of 14 patients. Cytomegalovirus esophagitis was associated with a poor long-term prognosis. CONCLUSION: Cytomegalovirus esophagitis in patients with AIDS is a well-defined entity with characteristic clinical symptoms and endoscopic findings, as well as histopathologic abnormalities.

Acquired Immunodeficiency Syndrome↗

Aerosolized pentamidine for prophylaxis against Pneumocystis carinii pneumonia. The San Francisco community prophylaxis trial.

BACKGROUND AND METHODS: Pneumocystis carinii pneumonia (PCP) is the most frequent life-threatening opportunistic infection associated with human immunodeficiency virus (HIV) infection. To assess the possible value of aerosolized-pentamidine prophylaxis in different doses, a controlled clinical trial was begun in 1987 with 408 subjects at 12 treatment centers. The participants were randomly assigned to receive 30 mg of pentamidine every two weeks, 150 mg every two weeks, or 300 mg every four weeks. RESULTS: Eighteen months after randomization, the subjects in the 300-mg arm had had 8 confirmed episodes of PCP while receiving treatment, as compared with 22 in the 30-mg arm (P = 0.0008). The 150-mg arm had intermediate results but ones not significantly different from those of the 300-mg arm. Participants with previous episodes of PCP and CD4-cell counts less than 200 per cubic millimeter were at the highest risk for PCP. CONCLUSIONS: Aerosolized pentamidine was effective for prophylaxis against PCP in patients infected with HIV, according to the dose and schedule of administration. It and zidovudine were well tolerated together and had independent prophylactic benefits.

Adult↗