洛匹那韦/利托那韦在冠状病毒治疗中的应用

目的：近20年来全球多次发生冠状病毒导致的严重危害公众健康的公共卫生事件，其高的传播效率、严重的感染后果以及捉摸不定的流行时间对人类健康构成严重威胁，而针对冠状病毒的治疗目前暂缺乏特效药物。HIV蛋白酶抑制剂复合制剂洛匹那韦/利托那韦广泛用于HIV的治疗，而用于治疗冠状病毒感染则相对少见。本文着重介绍洛匹那韦/利托那韦的药理作用、药动学特点及在冠状病毒感染治疗中的应用。     

Characterization of resistant HIV variants generated by in vitro passage with lopinavir/ritonavir

Lopinavir (LPV, formerly ABT-378) is an HIV protease inhibitor (PI) that is co-administered with a small amount of ritonavir (RTV), which greatly increases and sustains the plasma levels of LPV. Lopinavir/ritonavir (LPV/r) has shown potent antiviral activity in both therapy-nai;ve and PI-experienced patients. To assess the effect of pharmacologically relevant ratios of LPV/RTV (LPV/r) on the emergence of resistant HIV in vitro, HIV-1 pNL4-3 was passaged in the presence of increasing concentrations of LPV alone and LPV/r. Passages with fixed 5/1 and 15/1 concentration ratios of LPV/r initially selected I84V and I50V/M46I mutants, respectively. Selection with LPV alone also generated the same initial mutants (I50V/M46I) as the 15/1 LPV/r passage. Further passage produced other mutations previously found to be associated with PI-resistance. Phenotypic susceptibility to both LPV and RTV decreased with successive passages, irrespective of whether RTV was present in the selection experiment. Furthermore, in the two selection experiments that included RTV (at either 5/1 or 15/1 LPV/r ratio), the IC(50) of RTV at each passage evaluated was at least five-fold higher than the concentration of RTV employed at that passage, while the IC(50) of LPV toward the passaged virus was similar to the concentration of LPV used at that passage, indicating that the selective pressure was attributable to LPV and not RTV.     

Oxycodone concentrations are greatly increased by the concomitant use of ritonavir or lopinavir/ritonavir

Purpose  

This study aimed to investigate the effect of antivirals ritonavir and lopinavir/ritonavir on the pharmacokinetics and pharmacodynamics of oral oxycodone, a widely used opioid receptor agonist used in the treatment of moderate to severe pain.     

Pharmacokinetics of lopinavir/ritonavir in HIV/hepatitis C virus-coinfected subjects with hepatic impairment

The effect of hepatic impairment on lopinavir/ritonavir pharmacokinetics was investigated. Twenty-four HIV-1-infected subjects received lopinavir 400 mg/ritonavir 100 mg twice daily prior to and during the study: 6 each with mild or moderate hepatic impairment (and hepatitis C virus coinfected) and 12 with normal hepatic function. Mild and moderate hepatic impairment showed similar effects on lopinavir pharmacokinetics. When the 2 hepatic impairment groups were combined, lopinavir Cmax and AUC12 were increased 20% to 30% compared to the controls. Hepatic impairment increased unbound lopinavir AUC12 by 68% and Cmax by 56%. The effect of hepatic impairment on low-dose ritonavir pharmacokinetics was more pronounced in the moderate impairment group (181% and 221% increase in AUC12 and Cmax, respectively) than in the mild impairment group (39% and 61% increase in AUC12 and Cmax, respectively). While lopinavir/ritonavir dose reduction is not recommended in subjects with mild or moderate hepatic impairment, caution should be exercised in this population.     

Cost effectiveness of lopinavir/ritonavir tablets compared with atazanavir plus ritonavir in antiretroviral-experienced patients in the UK, France, Italy and Spain

BACKGROUND AND OBJECTIVE: Selection of antiretroviral therapy (ART) for antiretroviral-experienced patients should involve balancing multiple factors, including clinical efficacy, adverse-event risk, resistance concerns, cost effectiveness and expected budget impact. The efficacy of a regimen and its durability, as demonstrated in controlled clinical trials, must be considered in the light of short- and long-term economic impacts on the healthcare system. These impacts may vary based on drug costs, costs of reported adverse effects, the regimen's likelihood of contributing to viral resistance to second-line therapies and the marginal cost differences between other healthcare resources used over a patient's lifetime. Risk of coronary heart disease (CHD) may be of concern in the selection of ART, because differences in CHD risk factors have been reported for different regimens, and heart disease is both a deadly and costly condition. This study set out to estimate the long-term combined effects of HIV disease and antiretroviral-related risk for CHD on quality-adjusted survival and healthcare costs for antiretroviral-experienced patients in the UK, Spain, Italy and France. METHODS: A previously validated Markov model was updated with 2006 cost estimates for each of the four countries and supplemented with the Framingham CHD risk equation. In the model, the average patient was male, aged 37 years, with a baseline 10-year CHD risk of 4.6%. Patients started with either lopinavir/ritonavir (LPV/r) or ritonavir-boosted atazanavir (ATV+RTV) as the protease inhibitor (PI). Clinical trial results, local drug costs and AIDS and CHD cost estimates were used to estimate the differences between these two therapies. RESULTS: There was a significant advantage using LPV/r over ATV+RTV, which varied depending on the country's cost structure and assumptions related to drug efficacy. There was a comparative benefit for experienced patients in quality-adjusted life-months (QALM) of 4.6 (the net gain after subtracting quality-adjusted life-years [QALYs] lost owing to CHD risk). In addition, there were 5- and 10-year overall cost savings of between euro947 and euro6594 per patient after 5 years, and an impact ranging from a cost increase of euro308 (for France) to a cost saving of euro7388 (for Spain) at year 10. The lifetime incremental cost-effectiveness ratios ranged from dominant for Spain to euro11 856/QALY for Italy. CONCLUSION: LPV/r was a highly cost-effective regimen relative to ATV+RTV for the treatment of HIV for each of the four countries examined in this study. The effect of LPV/r on long-term CHD risk was minimal compared with the increased risk of AIDS/death projected for a less efficacious PI-based regimen. The cost of lipid-lowering drugs and treatment for CHD was insignificant compared with the overall cost savings from LPV/r therapy. The choice of regimen for antiretroviral-experienced patients should be based on a regimen's expected efficacy and durability for countries with similar cost structure to those examined here.     

Simplification of therapeutic drug monitoring for twice-daily regimens of lopinavir/ritonavir for HIV infection

Cost and inconvenience limit the application of full 12-hour pharmacokinetic (PK) analysis for routine therapeutic drug monitoring of antiretroviral medications. We explore whether lopinavir (LPV) and ritonavir (RTV) exposures can be estimated with limited sampling for patients taking twice-daily LPV/RTV. One hundred and one PK profiles from 81 patients, most receiving salvage therapies including twice-daily LPV/RTV, were obtained for the analysis. After a minimum of 2 weeks on a stable regimen, blood was drawn immediately before and at 1, 2, 4, 6, 8, 10, and 12 hours after a timed medication dose. Plasma drug concentrations were determined by a validated HPLC-MS-MS assay. Peak concentrations, evening troughs, and AUC0-12 h were entered into linear and log10-log10 linear regression models to determine the best correlation with LPV and RTV plasma concentrations using a maximum of 2 time points. The accuracy and precision of PK parameter estimates of the resultant models were tested on data collected for an additional 25 patients. Twelve models using various combinations of 2 timed LPV concentrations afforded accurate (maximum % bias = -6.45) and precise (relative standard deviation < 15%) estimates for the LPV peak concentration or AUC0-12h. Four sets of 2 concentrations provided simultaneous estimates of both PK parameters, with the best estimates derived from data collected at 2 and 6 hours postdose. Evening trough concentrations were the best estimators of the daily nadir; however, no adequate substitute for collecting blood 12 hours postdose emerged from this analysis.     

Avascular necrosis of the femoral head in a HIV-1 infected patient receiving lopinavir/ritonavir

The wide use of protease inhibitors (PI) as part of a highly active antiretroviral (HAART) regimen is associated with the development of several side effects. Among these, the development of avascular necrosis (AVN) of the bone is being reported more frequently and it has been related both to the use of PI and to HIV-1 infection itself. We report here a case of AVN of the bone in a patient taking the new PI lopinavir (LPV)/ritonavir (RTV) as part of a HAART regimen.     

CYP3A4-mediated lopinavir bioactivation and its inhibition by ritonavir

The combination of lopinavir (LPV) and ritonavir (RTV) is one of the preferred regimens for the treatment of HIV infection with confirmed efficacy and relatively low toxicity. LPV alone suffers the poor bioavailability due to its rapid and extensive metabolism. RTV boosts the plasma concentration of LPV by suppressing its metabolism and thus increasing LPV efficacy. In the current study, we found that RTV also inhibits LPV bioactivation. LPV bioactivation was investigated in human liver microsomes and cDNA-expressed human cytochromes P450. Twelve GSH-trapped reactive metabolites of LPV were identified by using a metabolomic approach. Semicarbazide-trapped reactive metabolites of LPV were also detected. RTV effectively suppressed all pathways of LPV bioactivation via CYP3A4 inhibition. Our data together with previous reports suggest that LPV plus RTV is an ideal combination because RTV not only boosts LPV plasma concentration, but it decreases LPV bioactivation.     

Lopinavir/ritonavir: appraisal of its use in HIV therapy

Recommendations for a highly active antiretroviral therapy in either pretreated patients or symptomatic patients with an AIDS-defining event include at least one protease inhibitor. The majority of currently available protease inhibitors are coadministrated with low-dose ritonavir, a pharmacoenhancer that significantly increases protease inhibitor plasma concentrations. In the class of protease inhibitors lopinavir plus ritonavir is the only coformulation. This coformulation was designed to overcome the problems of earlier agents of this class of drugs concerning unfavorable pharmacokinetics with a higher frequency of dosing and therapy failure. The pharmacoenhancing effect of ritonavir on lopinavir resulted in a highly potent, clinically effective antiretroviral drug with a high genetic barrier to viral resistance. Safety concerns have taken a backseat, focusing instead on the favorable efficacy of lopinavir, which recently led to the evaluation of its use in boosted double-protease-inhibitor regimens, as a once-daily application and even in HIV monotherapy. Nevertheless, since HIV infection became a chronic but controllable disease, side effects like metabolic disorders and cardiovascular disease have begun to draw increased attention in the long-term treatment with protease inhibitors. Coformulated lopinavir/ritonavir is available as a soft gelatin capsule (133.33/33.33 mg), liquid formulation (80/20 mg/ml) and recently approved melt-extrusion tablet (200/50 mg). Lopinavir/ritonavir is recommended for first- and second-line therapy in HIV-1 infection, in children as well as adolescents and adults.     

吡喹酮片致脱发

患者女,38岁。2000年3月18日因间断癫痫发作5年余就诊。5年前患者大便曾有绦虫节片史。查体:体重61Kg,精神尚可,反应稍迟钝,毛发正常,无头癣等其他皮肤病,心、肺听诊正常,腹软,肝肋下未及,脾肋下4cm可及,病理反射未引出。囊虫补体结合试验阳性,脑CT提示:多发囊虫结节并囊虫钙化灶。给予患者吡喹酮片400mg口服3次/d,10d为1个疗程,在1个疗程后停20d,再进行第2个疗程,依次类推共进行5个疗程,时间持续5个月。在每一个疗程的前7d给予甘露醇250ml+地塞米松10mg静脉滴注,1次/d。第一个疗程的第5天时患者洗落约70%;10d后停服吡喹酮,患者头发又逐渐…     

Evidence for time-dependent interactions between ritonavir and lopinavir/ritonavir plasma levels following P-glycoprotein inhibition in Sprague-Dawley rats

The interaction between verapamil, a P-glycoprotein (P-gp) inhibitor, with ritonavir and lopinavir/ritonavir (LPV/r) after acute and chronic treatment was investigated in rats. Rats were divided into 4 groups, viz. Group 1: ritonavir, 20 mg/kg/d (n=18), group 2: ritonavir, 20 mg/kg/d plus verapamil 5 mg/kg/d (n=18), group 3: LPV/r, 80 and 20 mg/kg/d (n=17) and group 4: LPV/r, 80 and 20 mg/kg/d plus verapamil 5 mg/kg/d (n=18). Blood samples were collected after decapitation on days 1, 7 and 21. Lopinavir and ritonavir plasma levels were simultaneous determined by a validated LC/MS/MS method. The lower limit of quantification for both ritonavir and lopinavir was 0.078 μg/ml. Verapamil significantly increased ritonavir plasma levels, administered as monotherapy, following acute (p<0.005) and chronic treatment (day 21) (p<0.005). During acute (but not chronic) LPV/r treatment, verapamil also increased the lopinavir levels (p<0.05). A time or exposure dependent pharmacokinetic interaction was thus observed between verapamil and ritonavir whether administered alone or after the lopinavir-ritonavir combination (LPV/r). This interaction occurred most prominently after acute treatment, and became less pronounced over time. This study indicates the importance of a longer time frame to investigate enzyme based drug interactions in rat models.