General Information

Baxdela (delafloxacin) is a fluoroquinolone antibacterial.

Baxdela is specifically indicated for use in adults for the treatment of acute bacterial skin and skin structure infections (ABSSSI) caused by susceptible isolates of the following:

Gram-positive organisms: Staphylococcus aureus (including methicillin-resistant [MRSA] and methicillinsusceptible [MSSA] isolates), Staphylococcus haemolyticus, Staphylococcus lugdunensis, Streptococcus agalactiae, Streptococcus anginosus Group (including Streptococcus anginosus, Streptococcus intermedius, and Streptococcus constellatus), Streptococcus pyogenes, and Enterococcus faecalis.

Gram-negative organisms: Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, and Pseudomonas aeruginosa

Baxdela is supplied as a tablet for oral administration and a solution for intravenous infusion. The recommended dosing is as follows: Administer Baxdela for injection 300 mg by intravenous infusion over 60 minutes, every 12 hours. Administer Baxdela tablet 450-mg orally every 12 hours for 5 to 14 days total duration. The dosage for patients with renal impairment is based on the estimated glomerular filtration rate (eGFR). Please see drug label.

Clinical Results

FDA Approval

The FDA approval of Baxdela was based on two phase III trials. A total of 1,510 adults with acute bacterial skin and skin structure infections (ABSSSI) were randomized in two multicenter, multinational, double-blind, double-dummy, non-inferiority trials. Trial 1 compared Baxdela 300 mg via intravenous infusion every 12 hours to comparator. In Trial 2, patients received Baxdela 300 mg via intravenous infusion every 12 hours for 6 doses then made a mandatory switch to oral Baxdela 450 mg every 12 hours. In both studies, the comparator was the intravenous combination of vancomycin 15 mg/kg actual body weight and aztreonam. Both IV and oral Baxdela monotherapy was statistically non-inferior to the combination of vancomycin plus aztreonam at the FDA primary endpoint of early clinical response at 48-72 hours.

Side Effects

Adverse effects associated with the use of Baxdela may include, but are not limited to, the following:

nausea

diarrhea

headache

transaminase elevations

vomiting

The Baxdela drug label comes with the following Black Box Warning:

Fluoroquinolones have been associated with disabling and potentially irreversible serious adverse reactions that have occurred together, including: Tendinitis and tendon rupture, Peripheral neuropathy, Central nervous system effects. Discontinue Baxdela immediately and avoid the use of fluoroquinolones, including Baxdela, in patients who experience any of these serious adverse reactions. Fluoroquinolones may exacerbate muscle weakness in patients with myasthenia gravis. Avoid Baxdela in patients with known history of myasthenia gravis.

Mechanism of Action

Baxdela (delafloxacin) is a fluoroquinolone antibacterial. The antibacterial activity of delafloxacin is due to the inhibition of both bacterial topoisomerase IV and DNA gyrase (topoisomerase II) enzymes which are required for bacterial DNA replication, transcription, repair, and recombination. Delafloxacin exhibits a concentration-dependent bactericidal activity against gram-positive and gram-negative bacteria in vitro.