Successful Treatment of Tenofovir Alafenamide-Induced Lactic Acidosis: A Case Report.

Nucleoside or nucleotide analogues (NAs) have the potential to cause lactic acidosis by inhibiting DNA polymerase-γ of human mitochondria and impairing aerobic metabolism. Patients may be asymptomatic, have mild non-specific symptoms, or present in multisystem organ failure. There is a paucity of data to guide management of life-threatening lactic acidosis due to NA therapy. Here we describe a case of a 60-year old critically ill male with decompensated cirrhosis secondary to hepatitis B virus (HBV) infection who developed severe lactic acidosis (13.8 mmol/L) 2 days after initiation of tenofovir alafenamide (TAF). All other possible etiologies for the elevated lactate were ruled out. Lactic acidosis resolved rapidly with TAF discontinuation and supplementation with cofactors supporting mitochondrial oxidative phosphorylation, including coenzyme Q10, levocarnitine, riboflavin, and thiamine. This case highlights the ability of TAF to cause lactic acidosis early after therapy initiation, especially in susceptible hosts, and reviews the potential role for cofactor supplementation for drug-induced mitochondrial injury.

Real world prescribing practices of apixaban or rivaroxaban lead-in doses for the treatment of venous thromboembolism in hospitalized patients.

The oral factor Xa inhibitors (OFXAi) apixaban and rivaroxaban are increasingly utilized for the treatment of venous thromboembolism (VTE) with recommended initial higher dose 7- and 21-day lead-in regimens, respectively. In patients receiving initial parenteral anticoagulation, it remains unknown if the full recommended higher dose OFXAi lead-in regimens are warranted, or if days can be subtracted. We aimed to describe when clinicians may deviate from recommended lead-in durations and evaluate clinical outcomes in these scenarios. This is a retrospective, observational study of patients 18 years or older who were treated with rivaroxaban or apixaban for acute pulmonary embolism (PE) or symptomatic proximal deep vein thrombosis (DVT) that received parenteral anticoagulation for at least 24 h before transitioning to the OFXAi. Among our cohort of 171 patients with acute VTE who received parenteral anticoagulation for a median of 48 h, 134 (78%) were prescribed a full OFXAi lead-in and 37 (22%) were prescribed a reduced lead-in. Patients in the reduced lead-in group were older with more cardiac comorbidities and antiplatelet use. There were four recurrent thromboembolic events within 3 months, two in the reduced lead-in group and two in the full lead-in group (5% vs. 2%, p = 0.206). Bleeding within 3 months occurred in 9 (5%) patients, with 6 events occurring in the reduced lead-in group and 3 events in the full lead-in group (16% vs. 2%, p = 0.004). Prescribing patterns of OFXAi lead-in therapy duration are variable in patients receiving initial parenteral anticoagulation. Larger cohorts are needed to better define the safety and efficacy of lead-in reduction.