Levofloxacin - Adverse Effects

Adverse Effects

See also: Adverse effects of fluoroquinolones

Most adverse reactions are mild to moderate; however, on occasion, serious adverse effects occur. Regulatory actions taken as a result of such adverse reactions included published warnings, additional warnings and safety information added to the package inserts, which includes Black Box Warnings together with the issuance of "Dear Doctor Letters" concerning the recent addition of the Black Box Warnings.

In 2004, the FDA requested new warning labels to be added to all of the Fluoroquinolones, including levofloxacin, regarding peripheral neuropathy (irreversible nerve damage), tendon damage, Heart Problems (prolonged QT Interval / Torsades de pointes), Pseudomembranous colitis, Rhabdomyolysis (muscle wasting), Stevens-Johnson Syndrome, as well as concurrent usage of NSAIDs contributing to the severity of these reactions.

Subsequent to this, on 25 June 2007, the FDA required the manufacturer to add an additional warning to the package inserts that stated that "Other serious and sometimes fatal events, some due to hypersensitivity, and some due to uncertain etiology, have been reported in patients receiving therapy with quinolones, including levofloxacin."

The serious adverse effects that may occur as a result of levofloxacin therapy include irreversible peripheral neuropathy, spontaneous tendon rupture and tendonitis, QTc prolongation/torsades de pointes, toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome, erythema multiforme, severe central nervous system disorders (CNS), including seizures and clostridium difficile associated disease (CDAD: Pseudomembranous colitis) photosensitivity/phototoxicity reactions, fatal hypoglycemia, kidney damage, rhabdomyolysis (muscle wasting), as well as anaphylactoid reactions and myasthenia crisis.

Additional serious adverse reactions include acute pancreatitis, temporary as well as permanent loss of vision, irreversible double vision, impaired color vision, exanthema, abdominal pain, malaise, drug fever, dysaesthesia and eosinophilia. Pseudotumor cerebri, commonly known as idiopathic intracranial hypertension (IIH), (also referred to as increased intracranial pressure), has been reported to occur as a serious adverse reaction to levofloxacin. Another serious adverse effect is autoimmune hemolytic anemia.

Older patients may have an increased risk of tendinopathy (including rupture), especially with concomitant corticosteroid use, and such patients may also be more susceptible to prolongation of the QT interval. Patients with known prolongation, those with hypokalemia, or being treated with other drugs that prolong the QT interval should avoid the use of Levaquin. Hematologic reactions (including agranulocytosis, thrombocytopenia), and renal toxicities may occur after multiple doses.

Children and the elderly are at a much greater risk of experiencing such adverse reactions. Such reactions may manifest during, as well as long after fluoroquinolone therapy had been discontinued.

Serious visual complications have also been reported to occur with ophthalmic fluoroquinolone therapy, which may also occur with levofloxacin eye drops, especially corneal perforation, but also evisceration and enucleation. This increased incidents of corneal perforation may be due to fluoroquinolones causing alterations in stromal collagen, leading to a reduction in tectonic strength. As noted previously permanent double vision (diplopia) has also been reported.

Some groups refer to these adverse events as "fluoroquinolone toxicity". These groups of people claim to have suffered serious long term harm to their health from using fluoroquinolones. This has led to a class action lawsuit by people harmed by the use of fluoroquinolones as well as legal action by the consumer advocate group Public Citizen. Partly as a result of the efforts of The State of Illinois and Public Citizen the FDA ordered a black box warnings on all fluoroquinolones advising consumers of the possible toxic effects of fluoroquinolones on tendons.