HIV (Human Immunodeficiency Virus) Essay

merciful immunodeficiency virus ( gentle Immunodeficiency Virus) causes help (Acquired Immune Deficiency Syndrome) that disables the immune system.It was discovered in 1983 .human immunodeficiency virus enters the body finished the blood linestream and duplicates itself rapidly.The victim is susceptible to infectious diseases that eventually are disgraceful (1).Statistically, HIV/ back up is the number one killer of Afri deal-American wo manpower ages 25 to 34, according to the Centers for Disease Control and Prevention.Between 2000 and 2003, they were cardinalteen times to a greater extent potential than White females and five times to a greater extent likely than Latino females to contract the disease.African-American men were seven-spot times more likely than White men and three times the rate of Hispanic men to contract HIV/AIDS (2).In 2008, there is still non a cure for AIDS.Instead, scientists bring in discovered do drugss that can s clinical depression target in th e progression of the disease. Protease inhibitors (PIs) are antiviral drugs that slow down the penetrate of HIV (1). The virus produces a protein called peptidase so that it can restate itself.Protease cuts long chains of proteins and enzymes into shorter chains, the first step in the influence by which HIV infects a cell (1).If this doesnt happen, replication does not continue.In 1987, AZT was the first anti-HIV medication that was created. It showed hope and kept raft healthier longer. However, the side do were very high for men. Since that time, more HIV medications have evolved.Antiretroviral therapy commonly consists of confederacys of nucleoside/nucleotide regress transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, protease inhibitors, or fusion inhibitors, which are prescribed in the after stages of HIV (19). Dual protease inhibitor therapy is also being use clinically (3).They are also associated with improving morbidity and mortality of HIV- unconditional persons (5).Although these drugs are expensive, they have proven to be the around favored therapy in managing HIV. However, some patients fathert comply vitamin C% with their treatments. This is largely due to the side set up. sometimes they make a patient feel worse than the actual disease.The just about commonly reported ones are abdominal pain, abnormal bowel movements, diarrhea, fatigue, headache, and nausea. Children usually develop a skin rash. The more serious side effects are liver problems and pancreatitis. Some patients have also seen large growing in triglyceride ad cholesterol levels. Diabetics saw an add-on in their blood sugar levels. another(prenominal) patients developed diabetes while taking protease inhibitors (16). Presently, nine PIs have been approved for use in the United States and Europe amprenavir, atazanavir, fosamprenavir, lopinavir, indinavir, ritonavir, saquinavir, tipranavir, and nelfinavir. tether non-nucleoside reverse transcript ase inhibitors (NNRTIs) are use for treatment of HIVnevirapine, delavirdine, and efavirenz (7). do drugs treatment selection depends on factors such as drug resistance, tolerability, drug interactions, and effectiveness. Therapeutic drug monitoring (TDM) has been proposed so that practitioners may better throw appropriate germ plasm concentrations of drugs in their patients by identifying interactions with other medications and assessing medication bond certificate (7). Figure 1 shows the structures of these compounds.Fig. 1. Chemical structures of protease inhibitors and non-nucleoside reverse transcriptase inhibitors. some 50% of treatment-nave patients dont have continued antiviral retort after one year of therapy (18). In some cases, there is a development of drug resistance and metabolic complications. Also, there is increasing tell that virological treatment failure is correlated with variations in the pharmacokinetic parameters of drugs (20). This can be due to drug int eractions, low bioavailability, and variations in metabolic enzyme activity. Atazanavir (ATV) has good unwritten bioavailability and a favorable pharmacokinetics profile (18). With this in mind, patients can mostly take a once-daily dose.A separate analytical regularity has been recently publish for quantifying ATV in human plasma using solid variant fall and HPLC with PDA (photodiode array) contracting at 201 nm (18). This method provides excellent dissolution of ATV from its inhering standard, clozapine (CLZ) and the other PIs, thus, obtaining an accurate measurement of the drug (see omen 2). CLZ elutes at 8.9 minutes, and ATV elutes a 24.4 minutes. A 40-ml injection resulted in a convalescence yield of 100%.Fig. 2. Chromatogram of ATV with PIs/NNRTIs (8000 ng/ml) spiked with CLZNelfinavir mesylate has been shown in phase III controlled clinical trials to significantly reduce viral load and increase CD4+ cell counts when used with reverse transcriptase inhibitors. Its pr escribed as distinguish of triple drug combination therapy (9). CD4+ are helper T cells. They are important for immune reconstitution in patients that are receiving antiretroviral therapy (10). After a large number of these cells are destroyed, AIDS develops (7).Six clinical trials was conducted in the past ten years using 2, 148 HIV- give children enrolled in the Pediatric AIDS Clinical Trials Group treatment trials (10). Patient ages varied from 2 to 7 years of age. The focus was to observe short-term variability of CD4 percentages. The study ground that 49% of patients had CD4 percentages above 25%. 32% of patients had CD4 counts in the midst of 15% and 24% 19% were less(prenominal) than 15%. Finally, 5.4% had a CD4% of less than 5% (10).In June 2006, Darunavir (DRV) was licensed in the United States. It is a promising PI that is ready against HIV strains that are resistant to the other PIs that currently on the market place (17). It is prescribed in 600-mg doses that are ta ken twice daily with 100 mg of ritonavir that acts as a booster.Protease inhibitors are associated with negative pharmacokinetics and many side effects such as gastrointestinal disturbances and lipide abnormalities (5).Four of the most common PIs used are indinavir, ritonavir, saquinavir, and nelfinavir (3). observe blood concentration of PIs, which can indicate some(prenominal) therapeutic and venomous levels of the drugs as sanitary as patient noncompliance with the medication, may remediate the care of both HIV-infected adults and children (3).When ritonavir was first introduced, it was given in doses of 600 mg every 12 minutes. However, patient intolerance of full doses led to its original use as a pharmacologic enhancer to increase the concentrations in plasma of a second protease inhibitor to improve the convenience of antiretroviral regimens by extending the dosing interval, reducing pill burden, and /or eliminating food-induced reductions in pharmacokinetic exposure ( 8).Researchers used mettlesome capital punishment Liquid Chromatography (HPLC) to determine concentrations of PIs in blood.Various methods have been used to study the pharmacokinetics and drug interactions. Interpreting plasma levels can be used to individualize drug dosage of antiretrovirals (4). type control (QC) procedures must be do to ensure that these methods are accurate and precise.Such procedures usually hold intralaboratory (inner) method validation, intralaboratory QC procedures, and participation in an interlaboratory QC program for antiretroviral drugs (4). Since the latter hadnt been done before, it was established so that laboratories can obtain better measurement results of antiretroviral drugs. golf club laboratories participated in the first part of the program.The first part of the experiment compound the measurement of the protease inhibitorsindinavir, nelfinavir, ritonavir, and saquinavir.All had a specified purity of 99% or higher.QC samples were active b y spiking blank plasma from HIV-negative volunteers with PI standard. The low concentrated standards ranged from 0.087 to 0.15 mg/L while the intermediate concentrated standards contained ranged from 2 to 3 mg/L of all four PIs.Finally, the high-concentrated standards contained approximately 5 to 11 mg/L of drug.All drugs were dissolved in wood alcohol following accurate weighings and thin out with blank plasma (4).High Performance Liquid Chromatography (HPLC) was used to analyze twelve samples.All laboratories measuring more than one protease inhibitor used as strain for simultaneous role (4).Six laboratories used HPLC/UV and three labs used HPLC-MS/MS. Mass spectrographic analysis detection is lots recommended for measurement of low concentration levels.Also, this type of analysis is usually faster and does not require complete resolution of drugs for detection and quantification (5). except five laboratories were able to measure all four PIs. threesome laboratories were not able to determine nelfinavir.One laboratory only thrifty indinavir (4).Acceptable accuracy results are between 80% and one hundred twenty%.Only indinavir resulted in an acceptable accuracy of 80%.The rest PIs had between 36% and 74% accuracy.These results should encourage laboratories to improve their analytical methods and QC procedures.Other PIs, such as amprenavir and lopinavir, can be analyse as well (4).HIV-positive plasma samples are heat inactivated before analysis, approximately 58C for 40 minutes, to decrease the risk of infection to the operator.They may also go through a freeze/thaw cycle. As with the QC study, blank plasma was spiked with seven PIs (indinavir, amprenavir, atazanavir, ritonavir, saquinavir, lopinavir, and nelfnavir) at low, intermediate, and high concentrations measured in ng/ml.Certain assays only require 100 l of plasma for analysis.This is discriminatory when measuring PI concentrations as part of clinical studies as they often necessitate hourly sampling to generate complete PK profiles therefore less blood can be drawn from the patient (5).In addition, seven PIs can be quantified in one assay, but impossible to assay all seven in a single preparation.The use of silver-tongued chromatography coupled to tandem mass spectrometry (LC-MS-MS) has emerged as the developmental method of choice supporting clinical and pre-clinical pharmacokinetic studies (13). Recovery for the HPLC-MS/MS methods was above 87% for all seven drugs at all three concentration levels (5).It was successful in quantifying seven PI concentrations in plasma of HIV positive persons that participated in a run time of nine minutes.Therefore, the assay may be used for determining PI concentrations in semen, lymphocytes, and cerebrospinal silver (5).A fast and highly-sensitive LC-MS-MS method was developed that could analyze five protease inhibitors (amprenavir, indinavir, nelfinavir, ritonavir, and saquinavir) in one run using an infixed standard. Sample s izes were weensy (ng/ml) and run times were approximately 5 minutes. Recoveries for all five PIs were between 87% and 92%(11).Tipranavir is part of a class of non-peptidic PIs that works against both wild-type virus and variants resistant to current PIs(6).It also has a high genic barrier.Tipranavir is prescribed in a 500-mg dose taken in combination with 200 mg of ritonavir twice daily as part of antiretroviral therapy for patients with HIV-1 strains that are resistant to multiple PIs (6).Fig. 3. Tipranavir chemical structureAn HPLC-UV method has been formalise and is currently applied when monitoring tipranavir (TPV) plasma levels in HIV patients.Samples were prepared for solid phase extraction (SPE) by conditioning the cartridges with 0.1% phosphoric acid, pH 7.TPV stock solutions with a concentration of 5 mg/ml were diluted from with 50% methanol. Samples were spiked with TPV at 1.875, 7.5, 18.75, 37.5, 60, and 75 g/ml in triplicate. QC samples were diluted with blank plasma and phosphate buffer to 5.625, 22.5, and 67.5 g/ml.clozapine was used as the privileged standard (6).5-ml aliquots of blood samples were obtained from HIV infected patients.The plasma obtained from centrifugation was heated at 60 C for one hour in a water bath.TPV in plasma was measured at a UV absorbance of 201 nm with a retention time of 32.2 minutes. Its internal standard, clozapine (CLZ) has a retention time of 8.3 minutes (6). Figure 4 below shows the chromatogram of TPV, its internal standard, and all other PIs and NNRTIspresent. Figure 5 shows TPV and its internal standard CLZ only.Fig. 4. Chromatogram of plasma control sample of TVP (22.5 mg/ml) spiked with internal standard and all PIs and NNRTIs.Fig. 5. Chromatogram of calibration sample of TVP (37.5 mg/ml) spiked with internal standard CLZ.Isocratic HPLC methods combined with the use of UV and fluorescence detection produces more sensitivity. Amprenavir is a fluorescent compound. Its internal standard PR25 can also be se en nether fluorescence (see figure 6).Fig. 6. Blank plasma with 100 ng/ml amprenavir and metre ng/ml of PR25 seen under fluorescence.In conclusion, much progress has been do in the development of protease inhibitors and other antiretroviral therapy. HPLC with UV detection has been the most commonly used method of analysis. It is rapid, simple, and highly sensitive. LC-MS-MS has been noted at the developmental method of choice for clinical and pre-clinical pharmacokinetic studies (13). More compounds can be analyzed in less time. Also, they can be used for methods using other human biological matrices.For the majority of protease inhibitors, all side effects are not known. In 2007, darunavir was the new HIV protease inhibitor with xi other antiretroviral agents on the market. They can affect patients that have diabetes, liver problems, and bleeders disease their conditions can worsen as a result of taking PIs. Only a patients health care provider can determine the best treatment optionREFERENCESNagel, Rob. 2007. Protease Inhibitors. UXL Encyclopedia of cognition cited 2008 whitethorn 8, in stock(predicate) from http//galenet.galegroup.com/servlet/SciRC?ste=1&docnum=cv2644301082.Health Hotline HIV and Genital herpes cited 2008 May8 Available from http//www.ebony.com.HPLC Assay for Common Protease Inhibitors Developed.Antiviral Weekly cited 2008 May 07 Available from http//galenet.galegroup.com/servlet/SciRC?ste=1&docNum=A60069570.Aarnoutse, Rob E., Verweij-van Wissen, Corrien P.W.G.M., van Ewijk-Beneken Kolmer, Eleonora, W.J., Wuis, Eveline, W., Koopmans, Peter P., Hekster, Yechiel A., and Burger, David, M. 2001. International Interlaboratory Quality Control Program for Measurement of Antiretroviral Drugs in Plasma Antimicrobial Agents and Chemo 46(3) 884-886.Dickinson, Laura, Robinson, Lesley, Tjia, John, Khoo, and Saye, Back, David. 2005. concurrent determination of HIV protease inhibitors amprenavir, atazanavir, indinavir, lopinavir, nelfinavir, riton avir and saquinavir in human plasma by high-performance runny chromatography-tandem mass spectrometry J of Chrom. B 82982-90.Colombo, S., Beguin, A., Marzolini, C., Telenti, A., Biollaz, J., and Decosterd, L.A. 2006. Determination of the novel non-peptidic HIV-protease inhibitor tipranavir by HPLC-UV after solid-phase extraction J of Chrom. B 832138-143.Rezk, Naser L., Tidwell, Richard R., and Kashuba, Angela D.M. 2004. High-performance unruffled chromatography assay for the quantification of HIV protease inhibitors and non-nucleoside reverse transcriptase inhibitors in human plasma J of Chrom. B 805241-247.Shelton, rig J.,Hewitt, Ross G., Adams, John, Dela-Coletta, Andrew, Cox, Steven, and Morse, Gene D. 2003. Pharmacokinetics of Ritonavir and Delavirdine in Human Immunodeficiency Virus-Infected Patients Antimicrobial Agents and Chemo 47(5) 1694-1699.Zhang, Kanyin E., Wu, Ellen, Patick, Amy K., Kerr, Bradley, Zorbas, Mark, Lankford, Angela, Kobayashi, Takuo, Maeda, Yuki, Shetty, Bhasker, and Webber, Stephanie. 2001.Circulating Metabolites of the Human Immunodeficiency Virus protease Inhibitor Nelfinavir in Humans Structural Identification, Levels in Plasma, and Antiviral Activities Antimicrobial Agents and Chemo 45(4) 1086-1093.Carey, Vincent J., Pahwa, Savita, and Weinberg, Adriana. 2005. Reliability of CD4 Quantitation in Human Immunodeficiency Virus-Positive Children Implications for Definition of immunological Response to Highly Active Antiretroviral Therapy Clinical and Diagnostic Lab Immunology 12(5) 640-643.Chi, Jingduan, Jayewardene, order Salientia L., Stone, Judith A., Motoya, Toshiro, and Aweeka, Francesca. 2002. Simultaneous determination of five HIV protease inhibitors nelfinavir, indinavir, ritonavir, saquinavir and amprenavir in human plasma by LC/MS/MS J of Pharm and biomedical Analysis 30675-684.Verbesselt, R., Van Wijngaerden, E., and de Hoon, J. 2007. Simultaneous determination of 8 HIV protease inhibitors in human plasma by isocratic h igh-performance liquid chromatography with combined use of UV and fluorescence detection Amprenavir, indinavir, atazanavir, ritonavir, lopinavir, saquinavir, nelfinavir and M8-nelfinavir metabolite J of Chrom. B 84551-60.Frerichs, Valerie A., DiFrancesco, Robin, and Morse, Gene D. 2003. Determination of protease inhibitors using liquid chromatography-tandem mass spectrometry J of Chrom, B 787393-403.Gangl, Eric, Utkin, Ilya, Gerber, Nicholas, and Vouros, Paul. 2002. Structural elucidation of metabolites of ritonavir and indinavir by liquid chromatography-mass spectrometry J. of Chrom. A 97491-101.Turner, Michele L., Reed-Walker, Kedria, King, Jennifer R., and Acosta, Edward P. 2003. Simultaneous determination of nine antiretroviral compounds in human plasma using liquid chromatography J. of Chrom. B 784331-341.2008. Kaletra. Cited 2008 May 16, Available from http//www.heartandsoul.com.DAvolio, Antonio, Siccardi, Marco, Sciandra, Mauro, Lorena, Baietto, Bonora, Stefano, Trentini, Lau ra, and Di Perri, Giovanni.2007. HPLC-MS method for the simultaneous quantification of the new HIV protease inhibitor darunavir, and 11 other antiretroviral agents in plasma of HIV-infected patients J. of Chrom. B 859234-240.Colombo, S., Guignard, N., Marzolini, C., Telenti, A., Biollaz, J., and Decosterd, L.A. 2004. Determination of the new HIV-protease inhibitor atazanavir by liquid chromatography after solid-phase extraction J. of Chrom. B 81025-34.Weller, Dennis R., Brundage, Richard C., Balfour, Jr., Henry H., and Vezina, Heather E. An isocratic liquid chromatography method for determining HIV non-nucleoside reverse transcriptase inhibitor and protease inhibitor concentrations in human plasma J. of Chrom. B 848369-373.Sarasa-Nacenta, Maria, Lopez-Pua, Yolanda, Mallolas, Josep, Blanco, Jose Luis, Gatell, Jose M., and Carne, Xavier. Simultaneous determination of the HIV-protease inhibitors indinavir, amprenavir, ritonavir, saquinavir and nelfinavir in human plasma by reversed-pha se high- performance liquid chromatography J, of Chrom. B 757325-332.