There is a paucity of information on the safety and efficacy of lipid-lowering therapy for dyslipidemia associated with human immunodeficiency virus (HIV) and antiretroviral therapy. Our objective was to determine whether fenofibrate and pravastatin were equivalent for the treatment of combined dyslipidemia in HIV as measured by a composite of the National Cholesterol Education Project (NCEP) goals based on absolute values for low-density lipoprotein (LDL), triglycerides (TG), and high-density lipoprotein (HDL) and to compare the safety of these agents through 48 weeks. This was a randomized, open-label trial with subjects assigned to fenofibrate 200 mg (n = 88) or pravastatin 40 mg (n = 86) daily. Subjects who failed to reach the NCEP composite goal on monotherapy by week 12 received both drugs. The composite goal at week 12 was achieved in 1% of fenofibrate and 5% of pravastatin subjects. At week 16, 69/88 subjects on fenofibrate added pravastatin (FP) and 67/86 subjects on pravastatin added fenofibrate (PF). At week 48, 7% FP subjects and 3% PF subjects achieved the composite goal. Median changes in LDL/HDL/TG/non-HDL were -8/+5/-144/+50 and -14/+2/-66/+34 mg/dl in subjects receiving FP and PF, respectively. There were few adverse events and no rhabdomyolysis reported. Combination therapy with fenofibrate and pravastatin for HIV-related dyslipidemia provides substantial improvements in lipid parameters and appears safe, but is unlikely to achieve all NCEP targets for lipid levels.
Efavirenz (EFV) is associated with hyperlipidemia when used in combination with other antiretroviral drugs. EFV is a mixed inducer/inhibitor of cytochrome P450 (CYP) 3A4 isozyme and may interact with hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors that are primarily metabolized via CYP3A4. To assess the drug-drug interaction of EFV used in combination with simvastatin (SIM), atorvastatin (ATR), or pravastatin (PRA), an open-label trial was conducted in 52 healthy adult HIV-seronegative subjects across AIDS Clinical Trials Group sites in the United States. Subjects received 40 mg of SIM, 10 mg of ATR, or 40 mg of PRA daily on days 0 through 3 and days 15 through 18. EFV was administered daily at a dose of 600 mg on days 4 through 18. SIM, ATR, and PRA concentrations were determined before and after EFV, and EFV concentrations were determined before and after statins. EFV reduced SIM acid exposure (area under the curve at 0 to 24 hours [AUC0-24 h]) by 58% (Wilcoxon signed rank test, P=0.003) and active HMG-CoA reductase inhibitory activity by 60% (P<0.001). EFV reduced ATR exposure by 43% (P<0.001) and the total active ATR exposure by 34% (P=0.005). EFV administration resulted in a 40% decrease in PRA exposure (P=0.005). SIM, ATR, and PRA had no effect on non-steady-state EFV concentrations. In conclusion, EFV, when administered with SIM, ATR, or PRA, can result in significant induction of statin metabolism. The reduced inhibition of HMG-CoA reductase activity during coadministration of EFV may result in diminished antilipid efficacy at usual doses of SIM, ATR, and PRA.
The 1H- and 13C-nmr spectra of taxol [1], 7-epi-taxol [2], and cephalomannine [3] were assigned using modern 1D and 2D nmr methods. Preliminary conformational information was obtained by nOe spectroscopy.
The demand for taxol, a promising cancer chemotherapeutic agent, far exceeds supply. Presently, taxol is derived from the bark of the Pacific yew, Taxus brevifolia, a small, slow-growing evergreen tree native to the northwestern United States. Knowledge of the distribution and magnitude of genetic and non-genetic sources of variation in taxol content in the genus Taxus is necessary if supply issues are to be met through plant harvesting. Analytical determinations of taxol, cephalomannine, and baccatin III in more than 200 trees representing several populations of T. brevifolia and other yew taxa indicate that (1) significant variation in taxane content exists among and within populations and species, (2) taxol levels exceeding those reported for T. brevifolia bark were found in shoots of individual trees from most taxa studied, and (3) the season in which samples are collected and handling procedures can influence taxane content.
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