Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0030305 (pancreatitis)
 16,014 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Didanosine is a dideoxynucleoside analogue which undergoes intracellular conversion to the putative active triphosphate metabolite. The active metabolite appears to inhibit viral reverse transcriptase and terminate the proviral DNA, and produces virustatic inhibition of actively replicating human immunodeficiency virus (HIV) at clinically relevant concentrations. In phase I studies didanosine had beneficial effects on various surrogate markers of clinical efficacy and also improved clinical manifestations of HIV infection, with a 21-month survival rate of 80% in patients with acquired immune deficiency syndrome (AIDS) and 93% in patients with AIDS-related complex (ARC) in 1 study. Didanosine also improved CD4+ cell counts in a phase II/III trial in patients previously treated with zidovudine, whereas cell counts declined in patients continuing zidovudine therapy. However, the effects of didanosine on clinical end-points (disease progression, survival, HIV encephalopathy) remain to be established. Peripheral neuropathy and pancreatitis are the predominant dose-limiting adverse events and didanosine therapy should be withdrawn in patients developing signs or symptoms of pancreatitis and during acute treatment of Pneumocystis carinii pneumonia. However, at currently recommended clinical dosages didanosine is generally well tolerated with minimal haematological toxicity. Thus, in a therapeutic area with few treatment options, didanosine offers a welcome alternative for patients intolerant of, or resistant to, zidovudine. There are a number of clinical trials in progress evaluating didanosine alone or in combination with other antiviral agents, and these results are awaited with considerable interest.
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PMID:Didanosine. A review of its antiviral activity, pharmacokinetic properties and therapeutic potential in human immunodeficiency virus infection. 137 14

Great strides have been made in the therapy of human immunodeficiency virus (HIV) infection. Currently approved drugs include zidovudine and didanosine. A third drug, dideoxycytidine (zalcitibine), has recently been filed for approval with the Food and Drug Administration. All these drugs work through inhibition of the reverse transcriptase enzyme. Zidovudine is the only drug that has shown clinical efficacy against HIV. Treatment of patients with advanced HIV disease (i.e., acquired immune deficiency syndrome [AIDS] or symptomatic infection with < 200 CD4+ lymphocytes per mm3), results in a prolongation and improved quality of life. Zidovudine is the only antiretroviral agent approved for the treatment of asymptomatic patients. Early intervention with zidovudine has been shown to delay progression to AIDS when patients' CD4+ lymphocyte counts decline to less than 500/mm3, irrespective of clinical signs or symptoms of HIV infection. Didanosine is currently indicated for the treatment of patients with advanced HIV disease who are intolerant to or failing zidovudine therapy. The major toxicity of zidovudine is bone marrow suppression with anemia and granulocytopenia (which occurs in from 1% to 45% of patients, depending on the clinical stage of disease and the dose of the drug). Didanosine and zalcitibine have both been associated with a severe peripheral neuropathy, which is generally reversible on cessation of the drug. In addition, didanosine has been implicated as a cause of pancreatitis that has been fatal in a small percentage of cases. The toxicities of didanosine and zalcitibine range from 1% to 10%, depending on dose, duration of therapy, and the presence of underlying HIV-related peripheral neuropathy or a previous history of pancreatitis. The clinical hallmark of HIV infection is the development of opportunistic infections and malignancies, which are a consequence of the profound immunodeficiency. The risk of an opportunistic infection increases significantly as the T-helper lymphocyte count declines to less than 20%, or 200 to 250/mm3. The spectrum of opportunistic infections ranges from viruses to protozoa. Patients with advanced HIV disease are also at increased risk of infection with nonopportunistic, community-acquired pathogens. Primary and secondary prophylaxis against the most common AIDS-defining opportunistic infection, Pneumocystis carinii pneumonia, is now recommended. Studies are currently underway to determine the efficacy of prophylaxis against other opportunistic pathogens. Treatment of opportunistic infections associated with AIDS has improved significantly over the past 5 years as new drugs and combination regimens of antimicrobials have been developed.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:AIDS: Part II. 139 36

In this article the literature about didanosine, an antiretroviral drug, is reviewed. The mechanism of action, biochemical pharmacology, pharmacokinetics, and clinical results of phase-I trials are discussed. Serious adverse effects such as pancreatitis and peripheral neuropathy have occurred in these trials. An antiretroviral effect was observed in terms of an increase in CD4+ lymphocytes and a decrease in p24 antigen levels in HIV-infected individuals. Didanosine seems to be a promising drug against HIV infection, but knowledge about its clinical efficacy is scanty.
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PMID:Didanosine, a new antiretroviral drug. A review. 143 13

There have been reports in the medical community of hesitation regarding the administration of didanosine to adult HIV patients because of the fear of the documented toxicities associated with didanosine. The most worrisome toxicities include pancreatitis and peripheral neuropathy. With close observation and follow-up, these toxicities can almost always be avoided or easily reversed. This article attempts to allay these fears so that the practitioner can administer this effective antiretroviral confidently and safely. The development of nucleoside and the pharmacology of didanosine are discussed. Drug administration information is provided, including a description of the different forms of didanosine currently available. Guidelines for assessing toxicities associated with didanosine, as well as suggestions for patient education, are also provided. Data gathered at the National Cancer Institute in the phase I didanosine trial indicate that early detection and discontinuation of didanosine, in nearly all cases, can limit or lessen the extent of morbidity.
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PMID:Didanosine use in the adult HIV patient. 146 32

Myelosuppression is associated with human immunodeficiency virus (HIV) infection and may also be produced by agents used for the treatment of the disease or the treatment of its complications. Didanosine (ddl; 2',3'-dideoxyinosine) is a newer purine nucleoside that has recently become available for therapy for HIV infection. The effects of didanosine on peripheral blood counts have been retrospectively evaluated in the first 170 patients treated with this new agent in four phase I trials. Patients treated with didanosine showed statistically significant improvements in hemoglobin levels, white cell counts, and granulocyte and platelet numbers as compared with baseline values. These changes were seen with or without prior therapy with zidovudine, were somewhat more pronounced at higher doses of didanosine, and persisted for up to 1 year. Reported adverse events included peripheral neuropathy, diarrhea, and most notably, pancreatitis. It is concluded that, while some toxic side effects occur, didanosine therapy in HIV infection is associated with an amelioration of HIV-induced myelosuppression.
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PMID:Effects of therapy with didanosine on hematologic parameters in patients with advanced human immunodeficiency virus disease. 146 12

2',3'-Dideoxyinosine (didanosine; ddI) was administered to 37 adults with AIDS or AIDS-related complex in an escalating-dose phase I study. Groups of three or four patients received intravenous dosages of 0.4 mg/(kg.d) to 25.6 mg/(kg.d) divided into two or three daily doses for 2 weeks, followed by oral ddI at twice the intravenous dosages. When given with antacids, ddI was well absorbed by the oral route and penetrated into the cerebrospinal fluid. The patients had an increase in mean number of CD4+ cells from 114/mm3 at entry to 161/mm3 at week 6 (P = .00004). They also had an increase in the CD4+/CD8+ ratio and in total number of lymphocytes. Sixteen of 18 evaluable patients had a decrease in levels of human immunodeficiency virus p24 antigen by week 6 (P = .0034). Many patients reported increased energy and appetite and gained weight. Dose-limiting toxicities at high dosages were painful peripheral neuropathy and sporadic pancreatitis. However, dosages up to 9.6 mg/(kg.d) have been tolerated in patients for 11-14 months. Thus, ddI has activity against human immunodeficiency virus at dosages that can be tolerated for approximately 1 year. However, life-threatening pancreatitis is a possible complication even at low dosages, and the best ways to manage and avoid adverse effects are still under study.
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PMID:The National Cancer Institute phase I study of 2',3'-dideoxyinosine administration in adults with AIDS or AIDS-related complex: analysis of activity and toxicity profiles. 197 24

Twenty-one patients with AIDS or AIDS-related complex (ARC) received 2',3'-dideoxyinosine (didanosine; ddI) intravenously and then orally (initial dosages of 0.4 mg/kg and 0.8 mg/kg every 12 hours, respectively) for 6-44 weeks in an escalating-dose study. The major dose-limiting effects were peripheral neuropathy (three patients) and pancreatitis (two patients), which were observed at dosages greater than or equal to 20 mg/(kg.d). Hyperuricemia occurred at greater than or equal to 30 mg/(kg.d). No hematologic toxicity developed except for possible sporadic thrombocytopenia (two patients). Significant decreases in serum levels of p24 antigen and increases in CD4+ and CD8+ lymphocytes were noted at 2, 6, and 10-20 weeks and over a wide range of dosages, including the lowest given. Most patients had an increased feeling of well-being and/or a weight gain of greater than or equal to 2 kg at 6 weeks. For this population, ddI has promise as a therapeutic agent, thus warranting further study of this agent in controlled clinical trials.
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PMID:2',3'-Dideoxyinosine in patients with AIDS or AIDS-related complex. 197 26

In a phase I dosage-finding trial, 2',3'-dideoxyinosine (didanosine; ddI) was administered once daily to 36 patients with AIDS or AIDS-related complex for up to 65 weeks (mean, 32.1 weeks) at six dosage levels. Thirteen of 18 patients previously treated with zidovudine had developed hematologic intolerance. The maximal tolerated dosage of ddI was 12 mg/(kg.d); dose-limiting toxicities were pancreatitis and peripheral neuropathy. Other toxicities included elevation in hepatic transaminase levels, rash, cardiac conduction abnormality, and asymptomatic hyperuricemia. Eighty-six percent of patients who completed 6 weeks of treatment showed improvement in constitutional symptoms and significant weight gain. In patients treated with ddI, the mean number of CD4+ lymphocytes increased from 124/mm3 at baseline to 199/mm3 at 24 weeks (P = .0027) and the mean leukocyte count, total lymphocyte count, and hemoglobin level showed increases (all P less than .01) after 12 weeks. Serum levels of viral p24 antigen decreased greater than or equal to 50% in 14 of 19 assessable patients. No differences between the responses of patients previously treated with zidovudine and those of zidovudine-naive patients were observed. These results indicate that ddI has significant antiretroviral activity in vivo and a toxicity profile different from that of zidovudine.
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PMID:Treatment of AIDS and AIDS-related complex with 2',3'-dideoxyinosine given once daily. 197 27

To evaluate the long-term toxicity and activity profile of 2',3'-dideoxyinosine (ddI), a potent inhibitor of human immunodeficiency virus (HIV) replication, in vitro. 58 patients with AIDS or AIDS-related complex were studied with additional reference to the effect of previous treatment with zidovudine, and the effect of ddI on HIV-induced cognitive dysfunction. Doses above 9.6 mg/kg per day of ddI were frequently associated with toxicity (peripheral neuropathy, pancreatitis, or hepatitis). Doses of 9.6 mg/kg per day or below were well tolerated for up to 21 months. A subset of patients receiving 3.2-9.6 mg/kg per day of ddI had long-term immunological improvement and reduction of serum HIV p24 antigen. Immunological changes were especially seen in patients who had little previous zidovudine therapy. 5 patients with HIV-induced cognitive impairment improved with ddI. Thus, ddI may have anti-HIV activity at doses which are tolerated for long-term therapy, although pancreatitis could be a life-threatening complication.
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PMID:Long-term toxicity/activity profile of 2',3'-dideoxyinosine in AIDS or AIDS-related complex. 197 29

Several dideoxynucleosides, including 3'-azido-2',3'-dideoxythymidine (zidovudine, azidothymidine, AZT), 2',3'-dideoxycytidine (ddC), and 2',3'-dideoxyinosine (ddI), have been shown to be potent inhibitors of human immunodeficiency virus (HIV) replication in human T cells and macrophages. These compounds undergo anabolic phosphorylation within target cells to a 3'-triphosphate moiety; as triphosphates, they act at the level of HIV DNA polymerase (reverse transcriptase). AZT has been shown to reduce the morbidity and mortality of patients with severe HIV infection and to at least temporarily ameliorate certain cases of HIV-induced dementia. In phase 1 studies, ddC and ddI have been shown to induce immunologic and virologic improvements in patients with AIDS or related disorders; phase 2 studies of ddC and ddI are underway. The use of these drugs can be associated with toxicity. AZT can cause bone marrow toxicity or myositis with prolonged use, ddC can cause peripheral neuropathy at high doses, and ddI can cause sporadic pancreatitis and peripheral neuropathy at high doses. For each compound, however, a therapeutic window exists in which an anti-HIV effect can be attained without short-term toxicity in most patients. Dose-intensity appears to be an important determinant of the toxicity of dideoxynucleosides. Studies are underway to explore how the therapeutic profiles of these compounds may be enhanced by attention to scheduling or through the use of combination therapy.
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PMID:Initial clinical experience with dideoxynucleosides as single agents and in combination therapy. 207 27


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