This study was designed to assess the safety, acceptability, pharmacokinetic (PK), and pharmacodynamic (PD) responses to rectal administration of tenofovir (TFV) 1% vaginally formulated gel and oral tenofovir disoproxil fumarate (TDF). This study was designed as a phase 1, randomized, two-site (United States), double-blind, placebo-controlled study of sexually abstinent men and women. Eighteen participants received a single 300-mg exposure of oral TDF and were then randomized 2:1 to receive a single and then seven daily exposures of rectal TFV or hydroxyethyl cellulose (HEC) placebo gel. Safety endpoints included clinical adverse events (AEs) and mucosal safety parameters. Blood and colonic biopsies were collected for PK analyses and ex vivo HIV-1 challenge. No serious AEs were reported. However, AEs were significantly increased with 7-day TFV gel use, most prominently with gastrointestinal AEs (p=0.002). Only 25% of participants liked the TFV gel. Likelihood of use "if somewhat protective" was ∼75% in both groups. Indices of mucosal damage showed minimal changes. Tissue TFV diphosphate (TFV-DP) C(max) 30 min after single rectal exposure was 6-10 times greater than single oral exposure; tissue TFV-DP was 5.7 times greater following 7-day versus single rectal exposure. In vivo exposure correlated with significant ex vivo tissue infectibility suppression [single-rectal: p=0.12, analysis of covariance (ANCOVA) p=0.006; 7-day rectal: p=0.02, ANCOVA p=0.005]. Tissue PK-PD was significantly correlated (p=0.002). We conclude that rectal dosing with TFV 1% gel resulted in greater TFV-DP tissue detection than oral dosing with reduced ex vivo biopsy infectibility, enabling PK-PD correlations. On the basis of increased gastrointestinal AEs, rectally applied, vaginally formulated TFV was not entirely safe or acceptable, suggesting the need for alternative rectal-specific formulations.
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http://dx.doi.org/10.1089/aid.2012.0262 | DOI Listing |
J Int AIDS Soc
March 2024
Division of Clinical Pharmacology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Nanoscale Adv
January 2024
Department of Chemistry, COMSATS University Islamabad, Abbottabad Campus Abbottabad Pakistan
Tenofovir (TFV) is an antiviral drug used to treat the co-infections of HIV/HBV viruses. Accurate monitoring of TFV drug levels is essential for evaluating patient adherence, optimizing dosage, and assessing treatment efficacy. Herein, we propose an innovative electrochemical sensing approach by using the alkaline phosphatase (ALP) enzyme with the support of BaTiO nanoparticles.
View Article and Find Full Text PDFFront Reprod Health
August 2023
Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA, United States.
Tenofovir (TFV) is an adenosine nucleotide analog with activity against HIV and HSV-2. Secondary analyses of clinical trials evaluating TFV gel as pre-exposure prophylaxis (PrEP) for HIV have shown that gel formulations of TFV provide significant protection against both HIV and HSV-2 acquisition in women who had evidence of use. An alternate quick-dissolving polymeric thin film, to deliver TFV (20 and 40 mg) has been developed as a potential multipurpose technology (MPT) platform.
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