Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Delavirdine (bisheteroarylpiperazine, U-90152), a nonnucleoside reverse transcriptase inhibitor of human immunodeficiency virus type 1 (HIV-1), was evaluated in a two-drug combination with recombinant human interferon-alpha (IFN-alpha) or the peptidomimetic protease inhibitor U-75875 against HIV-1 replication in vitro. Viral growth was assayed in a CD4+ T cell line (H9) infected with HIVIIIB and in human peripheral blood mononuclear cells infected with the clinical isolate HIVJRCSF. Drug synergy, estimated by the combination index method and the method of Pritchard and Shipman, was observed when delavirdine was combined with U-75875 or IFN-alpha over a range of drug concentrations (delavirdine: 0.001, 0.003, 0.01, 0.03 microM; U-75875: 0.01, 0.03, 0.1, 0.3, 1.0 microM; IFN-alpha: 2, 6, 17, and 50 or 10, 30, 100, and 300 IU/mL). The combinations showed no detectable drug antagonism or cytotoxicity. These in vitro synergy data support the potential use of delavirdine with either a protease inhibitor or IFN-alpha in patients with AIDS.
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PMID:In vitro inhibition of human immunodeficiency virus type 1 by a combination of delavirdine (U-90152) with protease inhibitor U-75875 or interferon-alpha. 752 53

Monotherapy with (-)2',3'-dideoxy-3'-thiacytidine (3TC) leads to the appearance of a drug-resistant variant of human immunodeficiency virus-type 1 (HIV-1) with the methionine-184 --> valine (M184V) substitution in the reverse transcriptase (RT). Despite resulting drug resistance, treatment for more than 48 weeks is associated with a lower plasma viral burden than that at baseline. Studies to investigate this apparent contradiction revealed the following. (i) Titers of HIV-neutralizing antibodies remained stable in 3TC-treated individuals in contrast to rapid declines in those treated with azidothymidine (AZT). (ii) Unlike wild-type HIV, growth of M184V HIV in cell culture in the presence of d4T, AZT, Nevirapine, Delavirdine, or Saquinavir did not select for variants displaying drug resistance. (iii) There was an increase in fidelity of nucleotide insertion by the M184V mutant compared with wild-type enzyme.
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PMID:Enhanced fidelity of 3TC-selected mutant HIV-1 reverse transcriptase. 899 51

Delavirdine is a nonnucleoside reverse transcriptase inhibitor with in vitro activity against human immunodeficiency virus type 1 (HIV-1) that is currently being evaluated in combination regimens with various nucleoside analogs, including didanosine. Due to the pH-dependent solubility of delavirdine, the buffering agents in didanosine formulations may reduce delavirdine absorption. To evaluate the potential interaction between these agents, 12 HIV-infected patients (mean [+/- standard deviation] CD4+ cell count, 304 +/- 213/mm3) were enrolled in a three-way crossover single-dose study. Didanosine (125 to 200 mg given as buffered tablets) and delavirdine mesylate (400 mg) pharmacokinetics were evaluated when each drug was given alone (treatments A and B, respectively), when the two drugs were given concurrently (treatment C), and when didanosine was given 1 h after delavirdine (treatment D). Delavirdine exposure was reduced by concurrent administration of didanosine. The maximum drug concentration in serum (Cmax) was reduced from 7.22 +/- 4.0 to 3.51 +/- 1.9 microM, and the area under the concentration-time curve from 0 h to infinity (AUC0-->infinity) was reduced from 22.5 +/- 14 to 14 +/- 5.7 microM.h. The extent of N-dealkylation, as indicated by the ratio of the N-dealkylated delavirdine AUC0-->infinity to the delavirdine AUC0-->infinity, was unchanged across study treatments (P = 0.708). Reductions in didanosine exposure were observed during concurrent administration with delavirdine with a Cmax reduction from 4.65 +/- 2.0 to 3.22 +/- 0.59 microM and an AUC0-->infinity reduction from 7.93 +/- 3.9 to 6.54 +/- 2.3 microM.h. Thus, concurrent administration of delavirdine and didanosine may reduce the AUC0-->infinity of both drugs, although the clinical significance of this reduction is unknown. Administration of delavirdine 1 h before didanosine avoided the interaction. Due to the single-dose nature of this study, these findings require further evaluation at steady state.
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PMID:Single-dose pharmacokinetics of delavirdine mesylate and didanosine in patients with human immunodeficiency virus infection. 898 Jul 74

Delavirdine (DLV), a non-nucleoside reverse transcriptase inhibitor (RTI) of human immunodeficiency virus type 1 (HIV-1), was evaluated in two and three-drug combinations against acute and co-culture infections of HIV-1JRCSF in human peripheral blood mononuclear cells. DLV combined with didanosine (DDI) at 1:10 and 1:30 ratios were statistically synergistic (combination indices (CI) < 1) at > 75% inhibition levels. However, at 1:100 ratio, the interaction appeared to be additive. Three-drug combinations of zidovudine (ZDV), DLV, and DDI (at a ratio of 1:2:333) were synergistic at 50-99% inhibition levels. The three-drug group also showed significantly (P < 0.01) lower p24 levels in acute cultures than two-drug combination groups (DLV + ZDV, DLV + DDI, ZDV + DDI). In co-culture studies, the extent of viral inhibition was dependent on drug dose and the duration of treatment. Combination of DLV, ZDV, and DDI at IC95 concentration of the individual drugs showed complete inhibition of viral growth in co-culture after 19 days, but not after 7 or 12 days of treatment. The combinations studied did not show additive or synergistic drug toxicity. These data provide an in vitro basis for beneficial use of DLV in combinations with DDI and ZDV in HIV-1 infected patients.
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PMID:Inhibition of human immunodeficiency virus type 1 infection in vitro by combination of delavirdine, zidovudine and didanosine. 910 85

ACTG 260 was an open-label, four-arm trial designed to study the safety and anti-human immunodeficiency virus (anti-HIV) activity of delavirdine monotherapy at three ranges of concentrations in plasma compared to those of control therapy with zidovudine or didanosine. Delavirdine doses were adjusted weekly until subjects were within their target trough concentration range (3 to 10, 11 to 30, or 31 to 50 microM). A total of 113 subjects were analyzed. At week 2, the mean HIV type 1 (HIV-1) RNA level declines among the subjects in the three delavirdine arms were similar (0.87, 1.08, and 1.02 log10 for the low, middle, and high target arms, respectively), but by week 8, the subjects in the pooled delavirdine arms showed only a 0.10 log10 reduction. In the subjects in the nucleoside arm, mean HIV-1 RNA level reductions at weeks 2 and 8 were 0.67 and 0.55 log10, respectively. Because viral suppression by delavirdine was not maintained, the trial was stopped early. Rash, which was usually self-limited, developed in 36% of subjects who received delavirdine. Delavirdine monotherapy has potent anti-HIV activity at 2 weeks, but its activity is time limited due to the rapid emergence of drug resistance.
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PMID:ACTG 260: a randomized, phase I-II, dose-ranging trial of the anti-human immunodeficiency virus activity of delavirdine monotherapy. The AIDS Clinical Trials Group Protocol 260 Team. 1034 55

To evaluate the pharmacokinetic effect of adding delavirdine mesylate to the antiretroviral regimens of human immunodeficiency virus (HIV)-infected patients stabilized on a full dosage of ritonavir (600 mg every 12 h), 12 HIV-1-infected subjects had delavirdine mesylate (400 mg every 8 h) added to their current antiretroviral regimens for 21 days. Ritonavir pharmacokinetics were evaluated before (day 7) and after (day 28) the addition of delavirdine, and delavirdine pharmacokinetics were evaluated on day 28. The mean values (+/- standard deviations) for the maximum concentration in serum (C(max)) of ritonavir, the area under the concentration-time curve from 0 to 12 h (AUC(0-12)), and the minimum concentration in serum (C(min)) of ritonavir before the addition of delavirdine were 14.8 +/- 6.7 micro M, 94 +/- 36 micro M. h, and 3.6 +/- 2.1 micro M, respectively. These same parameters were increased to 24.6 +/- 13.9 micro M, 154 +/- 83 micro M. h, and 6.52 +/- 4.85 micro M, respectively, after the addition of delavirdine (P is <0.05 for all comparisons). Delavirdine pharmacokinetic parameters in the presence of ritonavir included a C(max) of 23 +/- 16 micro M, an AUC(0-8) of 114 +/- 75 micro M. h, and a C(min) of 9.1 +/- 7.5 micro M. Therefore, delavirdine increases systemic exposure to ritonavir by 50 to 80% when the drugs are coadministered.
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PMID:Pharmacokinetics of ritonavir and delavirdine in human immunodeficiency virus-infected patients. 1270 42