Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027947 (neutropenia)
 17,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Zidovudine (ZDV) is the only approved antiviral for the treatment of human immunodeficiency virus infection (HIV) in the U.S. Although newer antivirals have reached Phase II testing, ZDV is now the accepted therapy against which all other agents will be compared. Zidovudine 1500 mg/d was previously prescribed only to adult HIV-infected patients who had developed AIDS or AIDS-related complex (ARC). However, results obtained from recently completed studies indicate that a lower daily dose (500 mg) appears to be equivalent. In addition, ZDV therapy appears to be beneficial to asymptomatic HIV-infected patients with CD4+ counts less than 500/mm3. The toxicity profile of ZDV, previously obtained from patients receiving 1500 mg/d, consisted of either acute (e.g., fever, rash, headache) or chronic (e.g., anemia, neutropenia, myopathy) adverse effects. ZDV pharmacokinetics are variable within and between the different subpopulations of HIV-infected patients who have been studied. Bioavailability ranges from 50 to 70 percent, and values for half-life, total body clearance, and volume of distribution are 1-2 h, 20-40 mL/min/kg, and 1-2 L/kg, respectively. Drug interactions occur primarily between ZDV and other agents that undergo hepatic glucuronidation (e.g., probenecid, sulfamethoxazole) resulting in decreased ZDV clearance. ZDV is currently measured by HPLC, radioimmunoassay and FPIA; however, the role of therapeutic monitoring is currently under investigation. Studies of ZDV therapy in neonates, pediatric patients, patients with resistant isolates of HIV, and HIV-infected patients receiving combined treatment with other reverse transcriptase inhibitors or immunomodulators are ongoing.
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PMID:Zidovudine update: 1990. 219 18

Although many experimental treatments are being evaluated for the treatment of acquired immunodeficiency syndrome (AIDS) and symptomatic HIV infection (ARC), only zidovudine (AZT) has been shown to prolong the lives of such patients. This article reviews the authors' experience with 101 patients with AIDS (73) or ARC (28) treated with AZT at a public hospital clinic in Los Angeles County. The patients were seen at least monthly for five to 87 weeks (means = 27.6) by nurse practitioners and physicians. Initiation of AZT therapy required a CDC-defined diagnosis of AIDS or an absolute CD4 lymphocyte cell count of 200/mm3 or less. The demographic distribution of the patient population was as follows: Caucasian, 59; Hispanic, 22; and black, 20. The mean age of the population was 37.4 years, and the predominant risk factor was homosexual contact (76 percent). Forty-one patients required modification of their AZT doses secondary to anemia, neutropenia, a combination of anemia and neutropenia, or for personal reasons. Thirty-four of the 41 patients (83 percent) never returned to full dose after reductions. The majority of these patients (81 percent) had AIDS and/or CD4 lymphocyte counts less than 150/mm3. Hematologic toxicity was common; 27 percent required blood transfusions. Of the 101 patients followed from five to 87 weeks, 87 percent were surviving after a mean of 45 weeks of AZT therapy. The article underscores the effectiveness of AZT in prolonging the lives of AIDS and ARC patients.
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PMID:Outcomes of treatment with AZT of patients with AIDS and symptomatic HIV infection. 234 66

Studies were done on 53 cats with community-acquired infection with the feline immunodeficiency virus (FIV) to determine if hematologic abnormalities were comparable with those observed in patients seropositive for the human immunodeficiency virus (HIV). Nine cats were asymptomatic, 24 had clinical symptoms equivalent to AIDS-related complex (ARC), and 20 had AIDS-like disease. Hematologic abnormalities were detected in 75% (40 of 53) of FIV-seropositive cats, and multiple concurrent cytopenias were common. Anemia, lymphopenia, neutropenia, and thrombocytopenia occurred in 36%, 53%, 34%, and 8% of FIV-seropositive cats, respectively. Cytopenias were seen only in symptomatic (ARC or AIDS) cats. The occurrence of cytopenias and the distribution of clinical stages were similar in cats with concurrent feline leukemia virus (FeLV) infection and those with FIV alone, suggesting that these abnormalities were a direct consequence of FIV infection. In addition, abnormalities were noted in 72% of marrows from symptomatic cats and included hyperplasia of individual cell lineages and dysmorphic features. Our results demonstrate that the hematologic manifestations of FIV infection are strikingly similar to those reported in HIV-seropositive patients. Thus, FIV infection in cats is an excellent animal model to study the pathogenesis of blood and marrow abnormalities in AIDS, as well as to evaluate the hematologic toxicities of drug therapies.
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PMID:Hematologic manifestations of feline immunodeficiency virus infection. 240 Aug 6

Zidovudine was used in an open uncontrolled study for treatment of 145 human immunodeficiency virus (HIV) patients, 102 with acquired immune deficiency syndrome (AIDS) and 43 with symptomatic HIV disease (acquired immune deficiency syndrome related-complex, ARC). The mean period of follow-up was 6 +/- 2.5 months. The median survival time of AIDS patients on zidovudine was 4.5 times longer when compared to a historical zidovudine untreated AIDS group (1657 vs. 370 days). This should be interpreted with reserve regarding improvements in treatment of all aspects of HIV infection and heightened awareness of AIDS which may have led to earlier diagnosis in the zidovudine treated groups. Pneumocystis carinii pneumonia (PCP) was very rarely a cause of death in zidovudine-treated patients (4.8%), while it was responsible for the death in 46.2% of historical controls (P less than 0.001). Extensive Kaposi's sarcoma was equally the cause of death in treated as well as in historical patients. Median T4 cell counts increased on zidovudine reaching a peak at the end of the fourth month of therapy in the ARC group and at the end of the first month in the AIDS group with a subsequent fall. Sixty per cent (53 of 87) patients were p24 viral antigen positive at the start of treatment and 19% of them had a fall of more than 50% in antigen level in three months while 32% became antigen negative within 2.5 months. Survival in patients where the antigen disappeared or in whom there was a major (greater than 50%) fall in antigen level was significantly higher than in those for whom there was no change in antigen level or in whom the antigen was negative at the start of the study (P less than 0.05). Forty-seven of the 145 zidovudine treated patients needed to be transfused because of anaemia. The mortality was significantly higher in this group of patients, particularly in those transfused prior to zidovudine therapy. Neutropenia occurred in four subjects. Platelets rose after the start of zidovudine but subsequently fell to thrombocytopenic levels in eight patients.
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PMID:Zidovudine treatment of patients with acquired immune deficiency syndrome and acquired immune deficiency syndrome-related complex: St Stephen's Hospital experience. 249 85

The efficacy and toxicity of oral azidothymidine has been studied in 145 patients with the acquired immunodeficiency syndrome (AIDS) or AIDS-related complex (ARC). The median survival time of AIDS patients on azidothymidine was 4.5 times higher when compared to a historical AIDS group who had not received the drug. This result must be interpreted with caution because of changes in treatment of HIV infection and growing awareness of AIDS which may have led to earlier diagnosis in the group treated with azidothymidine. The mortality was significantly higher in those patients who received transfusions and was particularly high in those who were transfused before azidothymidine. There was a significant difference in the occurrence of opportunistic infections in the patients who received transfusions compared with those who did not. AIDS patients treated immediately after an episode of Pneumocystis carinii pneumonia survived significantly longer than those in whom treatment was delayed for three months or more, and longer than those who were treated with azidothymidine because of another opportunistic infection or Kaposi's sarcoma. The T4 cell median counts increased in patients treated with azidothymidine reaching a peak at the end of the fourth month of treatment in the ARC group and at the end of the first month in the AIDS group with a subsequent fall in both groups. Sixty per cent of patients were p24 viral antigen positive at the start of treatment and 19 per cent of these patients had a fall of more than 50 per cent in antigen level while 32 per cent became antigen negative following treatment with azidothymidine. The mortality in the patients where the antigen disappeared or in whom there was a major fall of more than 50 per cent in antigen level was significantly less than in those where there was no change in antigen level. Twenty-nine patients were treated with azidothymidine because of skin Kaposi's sarcoma and in 17 tumour regressed or was stable. Thirty-two per cent of patients treated with azidothymidine became anaemic. Neutropenia occurred in 3 per cent of patients. Platelets increased initially after treatment but subsequently fell to thrombocytopenic levels in eight patients. Nine of 12 patients with thrombocytopenia before azidothymidine was commenced responded with an increased platelet count.
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PMID:The efficacy and toxicity of azidothymidine (AZT) in the treatment of patients with AIDS and AIDS-related complex (ARC): an open uncontrolled treatment study. 251 92

AZT is now the standard of care for all persons with AIDS, ARC or T4 helper cell levels less than 200/mm3. Some authorities are cautiously recommending it with full informed consent for patients who have fewer than 400 mm3 T4 cells or who have sustained a rapid fall in helper cells coupled with new symptoms. The optimum dosage remains to be determined. Although the package insert recommends 200mg p.o. q. 4 hours, b.i.d. and Q6 hour dosage regimes have been reported as being as effective with less toxicity. Folate and B12 levels should be measured and replaced when appropriate to avoid undue hematologic toxicity and therapy should be interrupted for hemoglobin less than 7.5 or neutropenia consisting of fewer than 750 leukocytes/cc. For progressive, less severe marrow toxicity the dose may be decreased to avoid a prolonged nadir. A CBC should be obtained every two weeks for at least the first eight weeks and monthly thereafter if counts are stable. Other toxicities to be monitored include elevated transaminases and co-administration with medications that affect hepatic glucuronidation such as probenecid, NSAID's and acetaminophen. In the eight years since this epidemic appeared on the medical horizon much has been learned about the disease and its treatment. More and more physicians are willing and eager to assume primary care responsibilities for their patients with AIDS and it is hoped AZT and other effective therapies will assist them in this process.
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PMID:AIDS in Arkansas. Zidovudine: an overview and rationale for use. 252 34

Therapy of patients with the acquired immunodeficiency syndrome (AIDS) or AIDS-related complex (ARC) with azidothymidine (AZT) and 2'-3'-dideoxycytidine (ddC) is complicated by severe anemia, neutropenia, and thrombocytopenia, the cause of which is unknown. We therefore tested the effect of AZT, ddC, and an additional 2'-3'-dideoxynucleoside analogue, 2'-3'-dideoxyadenosine (ddA), on the hematopoietic progenitor cells derived from the bone marrow of normal persons and patients with AIDS/ARC. All three substances dose-dependently inhibited the in vitro colony formation of the pluripotent (CFU-GEMM), as well as the erythroid (BFU-E) and granulocyte-macrophage progenitor cells (CFU-GM). The 50% inhibition of normal progenitors by AZT occurred at 0.13 microM for CFU-GEMM, 0.32 microM for BFU-E, and 1.9 microM for CFU-GM, by ddA at 15 microM for CFU-GEMM, 40 microM for BFU-E, and 140 microM for CFU-GM. ddC was the most toxic agent and already inhibited 71% +/- 16% (mean +/- standard error of the mean [SEM]) of CFU-GEMM and 52% +/- 22% of BFU-E at 0.1 microM, whereas the 50% inhibition of CFU-GM was reached at 0.3 microM. Hematotoxicity occurred at concentrations lower than necessary to inhibit the human immunodeficiency virus (HIV), except for ddA, which is 100 times less toxic than AZT whereas its antiviral effect is only 10 times less. The inhibition of progenitor cells from AIDS patients by the 2'-3'-dideoxynucleosides was comparable to normal progenitors, except for a higher sensitivity of AIDS-derived CFU-GEMM and BFU-E to AZT.
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PMID:Inhibitory effect of azidothymidine, 2'-3'-dideoxyadenosine, and 2'-3'-dideoxycytidine on in vitro growth of hematopoietic progenitor cells from normal persons and from patients with AIDS. 254 17

The first placebo-controlled trial of zidovudine in the management of HIV infection involved patients with the acquired immune deficiency syndrome (AIDS) following their first episode of Pneumocystis carinii pneumonia and patients with severe AIDS-related complex (ARC). Zidovudine was shown to increase survival, and the trial was terminated early at the request of an independent review board. In order to obtain more information on the long-term efficacy and tolerance of the drug the study was continued on an open-label basis where all patients were offered zidovudine. Data from this ongoing open-label study are reviewed on a regular basis. Side-effects associated with zidovudine include anaemia and neutropenia both of which are more predominant in patients with more advanced disease. Two basic strategies have been adopted with the aim of improving the therapeutic index of the drug involving (i) dose modification and (ii) combination with other antiviral or immunomodulatory compounds. Although several phase I and II studies are proceeding it is likely that research in this area will continue to expand. AIDS patients with Kaposi's sarcoma (but without a history of AIDS-defining opportunistic infection) were precluded from the original phase II trial described above. The value of zidovudine in the treatment of the sarcoma per se has yet to be established. Trials are currently in progress in this indication evaluating the potential of zidovudine administered either alone or in combination with interferon. Possibly the largest area of research is concerned with defining the role of zidovudine earlier in the course of HIV infection.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Current and future trials with zidovudine. 264 66

Zidovudine (azidothymidine) is a thymidine analogue antiretroviral drug active against human immunodeficiency virus (HIV). In acquired immunodeficiency syndrome (AIDS) and AIDS-related complex (ARC) patients, orally and intravenously administered zidovudine is effective in reducing the incidence of opportunistic infections and neoplasms, increasing helper T lymphocyte numbers, and improving survival rates and quality of life. Adverse effects include serious haematological abnormalities and severe headache, abdominal discomfort, nausea, myalgia and insomnia. In addition, neutropenia and other anaemias frequently limit zidovudine therapy and may result in a need for multiple blood transfusions, dose reductions or withdrawal of the drug. However, despite these problems and the lack of information about some aspects of zidovudine use, zidovudine provides a major hope for HIV-infected patients, and it has rapidly become the standard therapy for improving the quality and duration of the lives of AIDS and ARC patients.
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PMID:Zidovudine. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic efficacy. 266 Nov 94

Azidothymidine is a new antiviral drug that acts by competitive inhibition of reverse transcriptase of retroviruses. Azidothymidine is now widely used in treatment of patients with AIDS or ARC; the most important side effects of this drug are anaemia and neutropenia. Recently pigmentary changes of the nails (diffuse pigmentation and longitudinal or transverse bands) provoked by azidothymidine-treatment have also been reported. We describe a such case.
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PMID:[Nail pigmentation caused by azidothymidine]. 280 86


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