In clinical trials, the following events occurred in 1 to 3% of patients, regardless of drug relationship: dizziness 2.7%, abdominal pain 2.5%, dyspepsia 2.4%, vomiting 2.3%, vaginitis 1.8%, injection site pain 1.7%, flatulence 1.5%, pain 1.4%, pruritus 1.3%, sinusitis 1.3%, chest pain 1.2%, fatigue 1.2%, rash 1.2%, back pain 1.1%, injection site inflammation 1.1%, rhinitis 1.0%, taste perversion 1.0%.
In clinical trials, the following events, of potential medical importance, occurred at a rate of less than 1.0%, regardless of drug relationship: (See Table 6.)

In clinical trials using multiple-dose therapy, ophthalmologic abnormalities, including cataracts and multiple punctate lenticular opacities, have been noted in patients undergoing treatment with quinolones, including Levofloxacin. The relationship of the drugs to these events is not presently established.
Heart rate and Rhythm Disorders: Not known: ventricular arrhythmia and torsades de pointes (reported predominantly in patients with risk factor for QT prolongation), ECGQT prolonged Crystalluria and cylindruria have been reported with other quinolones.
The following laboratory abnormalities appeared in 2.2% of patients receiving Levofloxacin. It is not known whether these abnormalities were caused by the drug or the underlying condition being treated.
Blood Chemistry: decreased glucose.
Hematology: decreased lymphocytes.
Postmarketing Adverse Reactions: Additional adverse events reported from worldwide postmarketing experience with levofloxacin include: allergic pneumonitis, anaphylactic shock, anaphylactoid reaction, dysphonia, abnormal EEG, encephalopathy, eosinophilia, erythema multiforme, haemolytic anaemia, multi system organ failure, increased international normalised ratio (INR)/Prothrombin time, stevens-johnson syndrome, tendon rupture, torsades de pointes, vasodilation, Exacerbation of myasthenia gravis. Nervous system disorders (frequency not known): peripheral neuropathy (that may be irreversible) and polyneuropathy.