Delafloxacin

Oral:
ESRD, including patients undergoing haemodialysis: Not recommended.

eGFR (mL/min/1.73 m2)	Dosage
<15	Not recommended.

Intravenous:
ESRD, including patients undergoing haemodialysis: Not recommended.

eGFR (mL/min/1.73 m2)	Dosage
<15	Not recommended.
15-29	200 mg 12 hourly. Alternatively, initiate with 200 mg 12 hourly, then may consider switching to oral doses (no oral dose adjustments needed). Administer all IV doses via IV infusion over 60 minutes. Total treatment duration: 5-10 days (for community-acquired pneumonia) or 5-14 days (for skin and skin structure infections).

Delafloxacin May be taken with or without food. Administer at least 2 hr before or 6 hr after polyvalent cation-containing products.

Powder for solution for IV infusion: Reconstitute the vial labelled as containing 300 mg with 10.5 mL of dextrose 5% in water or NaCl 0.9% solution to make a 25 mg/mL concentration. Shake vigorously until the contents are completely dissolved. Further dilute the reconstituted solution using dextrose 5% in water or NaCl 0.9% solution to make a total volume of 250 mL with a final concentration of 1.2 mg/mL.

IV: Incompatible with any solutions containing polyvalent cations (e.g. calcium, magnesium) in the same IV line.

Hypersensitivity to delafloxacin or other fluoroquinolones. History of tendon disorders associated with fluoroquinolone use.

Patient with family history of aneurysm or congenital heart valve disease, pre-existing aortic aneurysm and/or dissection or other risk factors or conditions predisposing to aortic aneurysm and dissection (e.g. Takayasu arteritis, giant cell arteritis, Sjogren's syndrome, known atherosclerosis), heart valve disease or conditions predisposing to heart valve regurgitation/incompetence (e.g. infective endocarditis), risk factors for both aortic aneurysm and heart valve regurgitation/incompetence (e.g. Marfan syndrome, Ehlers-Danlos syndrome, Turner syndrome, Behcet's disease, rheumatoid arthritis, hypertension); known or suspected CNS disorder (e.g. epilepsy, severe cerebral arteriosclerosis), risk factors predisposing to seizures or lower seizure threshold, history of or risk factors for depression; diabetes, G6PD deficiency. Solid organ transplant recipients. Avoid use in patients with a known history of myasthenia gravis and those who have experienced any serious adverse reactions using fluoroquinolones. Renal impairment. Elderly. Pregnancy and lactation.

Significant: Disabling, prolonged and potentially irreversible serious effects, including tendinitis or tendon rupture (particularly Achilles tendon), CNS effects (e.g. dizziness, seizures, tremors, increased intracranial pressure, pseudotumour cerebri), psychiatric reactions (e.g. toxic psychosis, paranoia, hallucination), and peripheral neuropathy; glucose regulation disturbances (e.g. hypoglycaemia, hyperglycaemia); bacterial or fungal superinfection (prolonged use), including Clostridioides difficile-associated diarrhoea (CDAD) and pseudomembranous colitis. Rarely, haemolytic reactions (in G6PD-deficient patients).
Blood and lymphatic system disorders: Anaemia, leucopenia.
Cardiac disorders: Palpitation.
Ear and labyrinth disorders: Tinnitus, vertigo.
Eye disorders: Blurred vision.
Gastrointestinal disorders: Nausea, vomiting, diarrhoea, dysgeusia.
General disorders and administration site conditions: Infusion site reactions (IV).
Hepatobiliary disorders: Hypertransaminasaemia.
Musculoskeletal and connective tissue disorders: Myalgia, arthralgia.
Nervous system disorders: Headache.
Psychiatric disorders: Insomnia, confusion, abnormal dreams, anxiety.
Renal and urinary disorders: Renal impairment.
Respiratory, thoracic and mediastinal disorders: Dyspnoea.
Skin and subcutaneous tissue disorders: Pruritus, rash, urticaria.
Vascular disorders: Flushing, hypertension, hypotension.
Potentially Fatal: Aortic aneurysm rupture and dissection (sometimes complicated by rupture); severe exacerbation of myasthenia gravis; severe hypoglycaemia; severe hypersensitivity reactions, including anaphylaxis.

This drug may cause dizziness, lightheadedness or visual disorders, if affected, do not drive or operate machinery.

Perform culture and susceptibility tests; consult local institutional recommendations before treatment initiation due to antibiotic resistance risks. Monitor WBC and serum creatinine. Assess for signs and symptoms of hypersensitivity reactions, infection, tendinopathy, neuropathy, altered mental status, severe or bloody diarrhoea, and glucose regulation disturbances (particularly for diabetic patients).

Increased risk of tendinitis and tendon rupture with corticosteroids. Antacids containing magnesium or aluminium, sucralfate, multivitamins or drugs containing polyvalent cations (e.g. calcium, iron, zinc), and formulations with divalent or trivalent cations (e.g. didanosine buffered tab) may decrease the absorption and serum concentrations of oral delafloxacin.

Description:
Overview: Delafloxacin is a fluoroquinolone antibacterial agent. It exhibits concentration-dependent bactericidal activity in vitro against some Gram-positive and Gram-negative bacteria.
Mechanism of Action: Delafloxacin inhibits the topoisomerase IV and DNA gyrase (topoisomerase II) bacterial enzymes, which are necessary for bacterial DNA replication, transcription, repair and recombination.
Pharmacodynamics: Resistance to delafloxacin can occur due to mutations in the target bacterial enzymes topoisomerase IV and DNA gyrase, known as quinolone-resistance determining regions (QRDRs). It can also occur through altered efflux. Delafloxacin in vitro resistance develops by multiple step mutations in QRDRs of Gram-positive and Gram-negative bacteria (e.g. double mutations in gyrA and parC).
Pharmacokinetics:
Absorption: Bioavailability: 58.8%. Time to peak plasma concentration: Approx 1 hour.
Distribution: Plasma protein binding: Approx 84%, mainly to albumin.
Metabolism: Metabolised via glucuronidation by UGT1A1, UGT1A3, and UGT2B15.
Excretion: Oral: Via urine (50% as unchanged drug); faeces (48% as unchanged drug). IV: Via urine (65% as unchanged drug); faeces (28% as unchanged drug). Elimination half-life: 4.2-8.5 hours (after multiple oral doses); 3.7 hours (after single IV dose).

Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 487101, Delafloxacin. https://pubchem.ncbi.nlm.nih.gov/compound/Delafloxacin. Accessed Nov. 25, 2025.

Oral:
Tab: Store between 15-30°C.

Intravenous:
Intact vial: Store between 15-30°C. Reconstituted vial or diluted solution for IV infusion: May be stored between 20-25°C or under refrigeration (2-8°C) for up to 24 hours. Do not freeze.

Quinolones

J01MA23 - delafloxacin ; Belongs to the class of fluoroquinolones. Used in the systemic treatment of infections.

Baxdela Tablet and Injection Powder, Lyophilized, for Solution (Melinta Therapeutics, LLC). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 10/11/2025.

Brayfield A, Cadart C (eds). Delafloxacin. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 10/11/2025.

Delafloxacin Meglumine. UpToDate Lexidrug, AHFS DI (Adult and Pediatric) Online. American Society of Health-System Pharmacists, Inc. Waltham, MA. UpToDate, Inc. https://online.lexi.com. Accessed 10/11/2025.

Delafloxacin. Gold Standard Drug Database in ClinicalKey [online]. Elsevier Inc. https://www.clinicalkey.com. Accessed 10/11/2025.

Delafloxacin. UpToDate Lexidrug, Lexi-Drugs Multinational Online. Waltham, MA. UpToDate, Inc. https://online.lexi.com. Accessed 10/11/2025.

Joint Formulary Committee. Delafloxacin. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 10/11/2025.

Quofenix 300 mg Powder for Concentrate for Solution for Infusion (A. Menarini - Industrie Farmaceutiche Riunite - s.r.l). MHRA. https://products.mhra.gov.uk. Accessed 10/11/2025.

Quofenix 450 mg Tablets (A. Menarini - Industrie Farmaceutiche Riunite - s.r.l). MHRA. https://products.mhra.gov.uk. Accessed 10/11/2025.