From the FDA Drug Label
11 DESCRIPTION Levofloxacin tablets are a synthetic broad-spectrum antibacterial agent for oral administration. Chemically, levofloxacin, USP, a chiral fluorinated carboxyquinolone, is the pure (-)-(S)-enantiomer of the racemic drug substance ofloxacin
- The chemical name is (-)-(S)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid hemihydrate.
- Levofloxacin is a fluorinated carboxyquinolone, not a sulfonamide. The FDA drug label does not explicitly state that levofloxacin is a sulfonamide, and based on the chemical structure and classification, it is not a sulfonamide 1.
From the Research
No, Levaquin (levofloxacin) is not a sulfonamide. Levaquin belongs to the fluoroquinolone class of antibiotics, which works by inhibiting bacterial DNA gyrase and topoisomerase IV enzymes needed for bacterial replication [ 2 ]. Sulfa drugs, on the other hand, are sulfonamide antibiotics like sulfamethoxazole (found in Bactrim or Septra) that work by inhibiting bacterial folic acid synthesis. This distinction is important because patients with sulfa allergies can typically take Levaquin safely, as there is no cross-reactivity between these different antibiotic classes [ 3 ]. However, Levaquin has its own potential side effects, including tendon damage, peripheral neuropathy, and central nervous system effects [ 4 ]. If you have a documented sulfa allergy, you should still inform your healthcare provider about all your allergies when discussing antibiotic options, but Levaquin would generally be considered safe from a sulfa-allergy perspective [ 5 ].
Some key points to consider:
- Levaquin is a fluoroquinolone antibiotic with a broad spectrum of activity against Gram-positive and Gram-negative bacteria [ 2 ]
- It is not a sulfonamide antibiotic and does not work by inhibiting bacterial folic acid synthesis [ 3 ]
- Patients with sulfa allergies can typically take Levaquin safely, but should still inform their healthcare provider about all their allergies [ 4 ]
- Levaquin has its own potential side effects, including tendon damage, peripheral neuropathy, and central nervous system effects [ 5 ]
In terms of the evidence, the most recent and highest quality study [ 2 ] supports the use of Levaquin as a safe and effective antibiotic option for patients with sulfa allergies. The other studies [ 3, 4, 5 ] also provide evidence for the safety and efficacy of Levaquin, but are older and of lower quality. Therefore, the recommendation to use Levaquin in patients with sulfa allergies is based on the strongest and most recent evidence [ 2 ].