A pharmacist's role in the individualization of treatment of HIV patients.

The pharmacological treatment of HIV is complex and varies considerably among patients, as does the response of patients to therapy, requiring treatment plans that are closely tailored to individual needs. Pharmacists can take an active role in individualizing care by employing their knowledge of pharmacokinetics and pharmacogenetics and by interacting directly with patients in counseling sessions. These strategies promote the following: maintenance of plasma concentrations of antiretroviral agents within therapeutic ranges, prediction of pharmacological response of patients with certain genetic characteristics, and clinical control of HIV through the correct use of antiretroviral treatments. Together, these strategies can be used to tailor antiretroviral therapy to individual patients, thus improving treatment efficacy and safety.

Toxicogenetics of lopinavir/ritonavir in HIV-infected European patients.

AIMS: We present a genetic association study in 106 European HIV-infected individuals aimed at identifying and confirming polymorphisms that have a significant influence on toxicity derived from treatment with lopinavir/ritonavir (LPV/r). PATIENTS & METHODS: Genotyping was performed by matrix-assisted laser desorption/ionization-time of flight and KASPar® (KBiosciences, Hoddesdon, UK); LPV/r plasma concentrations were quantified using HPLC with an UV detection system and the pharmacokinetic parameters were estimated using Bayesian algorithms. Genetic association analysis was performed with PASW Statistics 18 (SPSS Inc., IL, USA) and R for Windows (Microsoft, WA, USA). RESULTS: Suggestive relationships have been established between lipid plasma levels and total bilirubin and SNPs in CETP, MCP1, ABCC2, LEP and SLCO1B3 genes and between diarrhea and SNPs in IL6 gene. CONCLUSION: Replication analysis should confirm the novel results obtained in this study prior to its application in the clinical practice to achieve a safer LPV/r-based combined antiretroviral therapy.

Impact of pharmacogenetics on CNS side effects related to efavirenz.

AIM: This article evaluates which genetic factors are involved in CNS toxicity related to long-term treatment with efavirenz (EFV) standard doses and their relationship with plasma concentrations. PATIENTS & METHODS: A total of 119 HIV-positive patients, in which 1350 EFV plasma concentrations, 68 SNPs and 14 EFV-related adverse effects (AEs) were analyzed. RESULTS: Overall, 32.77% of patients reported CNS toxicity and 8.40% had concentrations above the therapeutic range. A correlation was mainly found between patients with global CNS AEs and high EFV maximum steady-state plasma concentration (p = 1.47 × 10(-6)). A preliminary analysis confirmed that CYP2B6*6 (516G>T and 785A>G) was the most highly correlated (p = 0.005) with AEs and high plasma concentrations. In a second analysis adjusting for maximum steady-state plasma concentration, suggestive genetic associations were found between BCRP 421C>A, MRP1 816G>A, 5-HT2A 102C>T and different AEs. CONCLUSION: The finding of the involvement of these SNPs in EFV toxicity opens the door for further studies to confirm their validity and for their application in the future clinical practice. Original submitted 18 February 2013; Revision submitted 17 May 2013.

Disposition of linezolid in the isolated rat lung after systemic and pulmonary drug delivery.

OBJECTIVES: To characterize the distribution of linezolid in lung when it accesses this organ from the systemic circulation and when administered through the pulmonary route and to evaluate the influence of the 'respiratory mode' in the pulmonary distribution for both routes. METHODS: The study was conducted with 24 Wistar rats divided into four groups treated with linezolid under different experimental conditions. After the animals had been subjected to a tracheotomy followed by mechanical ventilation, the lungs were isolated. After a 5 min stabilization period, the antibiotic was administered through the systemic or the pulmonary route and samples of efferent fluid (EF) were collected using a previously programmed fraction collector. Samples of bronchoalveolar fluid (BALF) and of lung tissue were also taken at the end of each experiment. The concentrations of linezolid in the samples were determined using an HPLC technique with UV detection. RESULTS: The administration of linezolid through the inhalatory route significantly increased the levels of the drug in lung tissue and BALF with lung tissue/EF partition coefficients of 8.33 +/- 2.51 as compared with 1.90 +/- 0.78 for systemic administration. Also, the decrease in respiratory rate together with the increase in tidal volume favoured the process of linezolid distribution in pulmonary tissues and fluids. CONCLUSIONS: Administration through the pulmonary route affords and excellent method for passively vectoring linezolid to the pulmonary fluids and tissues and the respiratory mode seems to affect the disposition of the antibiotic in this tissue for both administration routes.

Pulmonary versus systemic delivery of antibiotics: comparison of vancomycin dispositions in the isolated rat lung.

Vancomycin dispositions in the respiratory system were compared after systemic and inhalatory administration under two respiratory conditions using the isolated-lung model. Inhalatory delivery led to much higher drug levels in pulmonary tissue and fluids. The respiratory pattern affects vancomycin disposition in the pulmonary system regardless of the administration route.