The reduced dose to tenofovir (Viread) of 150mg per day appears to be a safe and effective treatment for people with HIV who have moderate renal impairment, according to researchers in Thailand in a report in the online edition of Clínica Infectious diseases. The daily dose of 150mg provided similar drug exposure to the recommended dose of 300mg every 48 hours. In addition, treatment with the reduced dose maintains viral suppression.
“This is the first alternative assessment report to measure TDF [tenofovir] in HIV-infected adults with moderate renal dysfunction. Our data demonstrate that reducing the approved TDF dose to 300 mg every 48 hours in adults with a creatinine clearance between 30% at <50 ml / min to 150mg once daily provides comparable exposures over a 48 hour period after receiving an NNRTI [non-nucleoside analog reverse transcriptase inhibitors] - or lopinavir / ritonavir - therapy ”, comment the authors. "The preservation of virological suppression and the lack of adverse events was reassuring."
Tenofovir is a widely used antiretroviral. The standard dose is 300 mg once a day, in combination with other antiretroviral drugs. The drug is secreted through the kidneys. A pharmacokinetic study in HIV-negative patients with people with renal impairment showed that individuals with creatinine clearance below 50 ml / min were significantly higher in blood tenofovir levels. Therefore, it was calculated that tenofovir 300 mg dose every 48 hours for people with moderate renal impairment - creatinine clearance between 30-49ml / min - who offer exposure to drugs similar to what is seen in people with normal kidney function receiving the standard 300mg daily dose.
But many people feel that administering this dosage every 48 hours is confusing and inconvenient.
Tablets (150, 200, 250mg) have recently been approved for people with less resistance to tenofovir. The hypothesis formulated by the researchers is that the treatment with 150 mg once a day, offers the same exposure to the drug with the recommended dose of 300 mg for each period of 48 hours for adults with moderate renal impairment,
In phase I, open, the pharmacokinetic study involving 40 people living with HIV who had creatinine clearance between 30 and 50 ml / min, who were taking a tenofovir dose of 300 mg every 48 hours. All had their viral loads taken to the undetectable point; half of them were taking a combination based on an NRTI and the other 50% on a regimen containing lopinavir / ritonavir.
Tenofovir's blood levels were intensely scanned over a 48-hour period, and exposure to intracellular tenofovir was also monitored in peripheral blood mononuclear cells. The study participants were then linked to a dose of 150mg / day of tenofovir. After two weeks, the pharmacokinetic analysis was repeated.
Participants had an average age of 56 years and an average weight of 51kg. Mean creatinine clearance was 43,9 min / ml, serum creatinine and the median was 1,3 mg / dl. All had an undetectable viral load and the average CD4 count was 502 cells / mm3.
The mean plasma concentrations of tenofovir were essentially similar for the groups that received 300 and the groups that received 150mg, regardless of whether the participants were taking the drug in combination with an NRTI or ritonavir and lopinavir.
In general, people taking lopinavir / ritonavir had a tenofovir convent at higher levels in the plasma than people taking an NRTI. This was observed with both the groups of 300 and the 150mg groups of tenofovir.
The intracellular concentrations of tenofovir were comparable between the two groups; those of 300mg and those of 150mg.
“The data demonstrate that changing TDF to 150mg once daily in HIV-infected adults with moderate impairment of kidney function leads to exposure comparable to the current recommended 300mg, every 48 hours,” conclude the authors. “This daily dose is an option for this subpopulation of patients and may be preferable to simplify their antiretroviral regimens and facilitate adherence. However, kidney functions must continue to be closely monitored in these patients. ”
Published: May 22, 2015
Translated from the original in English in Lower daily dose of tenofovir 150mg safe and effective in people with moderate renal impairment by Cláudio Santos de Souza: “Yesterday, we hid to survive! Today, we show ourselves to live!
Cressey TR et al. Intracellular plasma and the pharmacokinetics of tenofovir disoproxil fumarate (TDF) 300mg every 48 hours versus 150mg / day in HIV-infected adults with moderate renal function impairment . Clin infect Dis, online edition, by 2015.
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