Sustained viral suppression with co-administration of oxcarbazepine and dolutegravir

Clinically Relevant Interactions Between Ritonavir-Boosted Nirmatrelvir and Concomitant Antiseizure Medications: Implications for the Management of COVID-19 in Patients with Epilepsy

Ritonavir-boosted nirmatrelvir (RBN) has been authorized recently in several countries as an orally active anti-SARS-CoV-2 treatment for patients at high risk of progressing to severe COVID-19 disease. Nirmatrelvir is the active component against the SARS-CoV-2 virus, whereas ritonavir, a potent CYP3A inhibitor, is intended to boost the activity of nirmatrelvir by increasing its concentration in plasma to ensure persistence of antiviral concentrations during the 12-hour dosing interval. RBN is involved in many clinically important drug–drug interactions both as perpetrator and as victim, which can complicate its use in patients treated with antiseizure medications (ASMs). Interactions between RBN and ASMs are bidirectional. As perpetrator, RBN may increase the plasma concentration of a number of ASMs that are CYP3A4 substrates, possibly leading to toxicity. As victims, both nirmatrelvir and ritonavir are subject to metabolic induction by concomitant treatment with potent enzyme-inducing ASMs (carbamazepine, phenytoin, phenobarbital and primidone). According to US and European prescribing information, treatment with these ASMs is a contraindication to the use of RBN. Although remdesivir is a valuable alternative to RBN, it may not be readily accessible in some settings due to cost and/or need for intravenous administration. If remdesivir is not an appropriate option, either bebtelovimab or molnupiravir may be considered. However, evidence about the clinical efficacy of bebtelovimab is still limited, and molnupiravir, the only orally active alternative, is deemed to have appreciably lower efficacy than RBN and remdesivir.

Doing More With Less: Review of Dolutegravir-Lamivudine, a Novel Single-Tablet Regimen for Antiretroviral-Naïve Adults With HIV-1 Infection

OBJECTIVE

To review data on efficacy and safety of dolutegravir (DTG) and lamivudine (3TC) in treatment-naïve adults with HIV-1 infection.

DATA SOURCES

Phase III clinical trials and review articles were identified through PubMed (1996 to March 2020) and ClinicalTrials.gov (2000 to May 2020) using the keywords dolutegravir, lamivudine, and HIV.

STUDY SELECTION AND DATA EXTRACTION

Relevant clinical trials and review articles available in English evaluating efficacy and safety of DTG and 3TC were included.

DATA SYNTHESIS

The once-daily, single-tablet regimen of DTG/3TC is the first dual antiretroviral therapy (ART) recommended for initial therapy in treatment-naïve adults with HIV-1 infection. DTG and 3TC were compared with a regimen of DTG and tenofovir disoproxil fumarate/emtricitabine in the GEMINI studies and demonstrated noninferiority for the primary end point of virological suppression at up to 96 weeks. No treatment-emergent resistance mutations were identified in a small group of participants who did not reach virological suppression. The regimen is well tolerated, and the most common adverse events reported in trials include headache, diarrhea, nausea, insomnia, and fatigue.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This dual-ART regimen is a favorable treatment option for ART-naïve patients with HIV-1 RNA <500 000 copies/mL, absence of hepatitis B virus, and no resistance to DTG or 3TC. Benefits of dual ART include reduction in treatment-related adverse events and toxicities, drug interactions, and cost. In addition, the once-daily, single-tablet formulation promotes adherence.

CONCLUSIONS

DTG/3TC has demonstrated efficacy in maintaining virological suppression in ART-naïve patients at up to 96 weeks while minimizing treatment-related adverse events and toxicities.

Drug-drug interactions of a two-drug regimen of dolutegravir and lamivudine for HIV treatment

INTRODUCTION

The GEMINI trials have recently shown that a two-drug regimen of dolutegravir plus lamivudine was non-inferior to a three-drug regimen in HIV-infected naïve patients. Accordingly, it is important that physicians be aware and confident about the drug-drug interactions (DDIs) involving dolutegravir, lamivudine, and other medications. Areas covered: Here, we firstly update the available information on the pharmacokinetic features of dolutegravir and lamivudine; subsequently, the articles mainly deals with the predictable DDIs for both antiretroviral drugs, attempting to underline their clinical implications. This review focuses on the DDIs of dolutegravir/lamivudine combined regimen and, therefore, does not provide an exhaustive list of all the potential DDIs involving the two single agents. A MEDLINE Pubmed search for articles published from January 2000 to December 2018 was completed matching the terms dolutegravir or lamivudine with pharmacokinetics, DDIs, and pharmacology. Moreover, additional studies were identified from the reference list of retrieved articles. Expert opinion: The antiretroviral dual regimen of dolutegravir and lamivudine represents an attractive therapeutic option for HIV in terms of DDIs. This is particularly relevant considering that the population with HIV is aging and is increasingly experience age-related comorbidities, increasing pill burden, polypharmacy and the risk of DDIs.