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Serious and Otherwise Important Adverse Reactions

The following serious and otherwise important adverse reactions are discussed in greater detail in the WARNINGS AND PRECAUTIONS section of the label:

• Tendinopathy and Tendon Rupture [see WARNINGS AND PRECAUTIONS]
• QT Prolongation [see WARNINGS AND PRECAUTIONS]
• Hypersensitivity Reactions [see WARNINGS AND PRECAUTIONS]
• Other Serious and Sometimes Fatal Reactions [see WARNINGS AND PRECAUTIONS]
• Central Nervous System Effects [see WARNINGS AND PRECAUTIONS]
• Clostridium difficile-Associated Diarrhea [see WARNINGS AND PRECAUTIONS]
• Peripheral Neuropathy [see WARNINGS AND PRECAUTIONS]
• Photosensitivity/Phototoxicity [see WARNINGS AND PRECAUTIONS]
• Development of Drug Resistant Bacteria [see WARNINGS AND PRECAUTIONS]

Clinical Trial Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

The data described below reflect exposure to AVELOX in 14981 patients in 71 active controlled Phase II- IV clinical trials in different indications [see INDICATIONS AND USAGE]. The population studied had a mean age of 50 years (approximately 73% of the population was < 65 years of age), 50% were male, 63% were Caucasian, 12% were Asian and 9% were Black. Patients received AVELOX 400 mg once daily PO, IV, or sequentially (IV followed by PO). Treatment duration was usually 6-10 days, and the mean number of days on therapy was 9 days.

Discontinuation of AVELOX due to adverse events occurred in 5.0% of patients overall, 4.1% of patients treated with 400 mg PO, 3.9% with 400 mg IV and 8.2% with sequential therapy 400 mg PO/IV. The most common adverse events leading to discontinuation with the 400 mg PO doses were nausea (0.8%), diarrhea (0.5%), dizziness (0.5%), and vomiting (0.4%). The most common adverse event leading to discontinuation with the 400 mg IV dose was rash (0.5%). The most common adverse events leading to discontinuation with the 400 mg IV/PO sequential dose were diarrhea (0.5%), pyrexia (0.4%).

Adverse reactions occurring in ≥ 1% of AVELOX-treated patients and less common adverse reactions, occurring in 0.1 to < 1% of AVELOX-treated patients, are shown in Tables 2 and Table 3, respectively. The most common adverse drug reactions ( ≥ 3%) are nausea, diarrhea, headache, and dizziness.

Table 2 : Common ( ≥ 1.0%) Adverse Reactions Reported in Active-Controlled Clinical Trials with AVELOX

Table 3 : Less Common (0.1 to < 1.0%) Adverse Reactions Reported in Active-Controlled Clinical Trials with AVELOX (N=14,981)

Laboratory Changes

Changes in laboratory parameters, without regard to drug relationship, which are not listed above and which occurred in ≥ 2% of patients and at an incidence greater than in controls included: increases in MCH, neutrophils, WBCs, PT ratio, ionized calcium, chloride, albumin, globulin, bilirubin; decreases in hemoglobin, RBCs, neutrophils, eosinophils, basophils, PT ratio, glucose, pO₂, bilirubin, and amylase. It cannot be determined if any of the above laboratory abnormalities were caused by the drug or the underlying condition being treated.

Postmarketing Experience

Table 4 lists adverse reactions that have been identified during post-approval use of AVELOX. Because these events are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Table 4: Postmarketing Reports of Adverse Drug Reactions

Antacids, Sucralfate, Multivitamins and other products containing Multivalent Cations

Quinolones form chelates with alkaline earth and transition metal cations. Oral administration of quinolones with antacids containing aluminum or magnesium, with sucralfate, with metal cations such as iron, or with multivitamins containing iron or zinc, or with formulations containing divalent and trivalent cations such as VIDEX® (didanosine) chewable/buffered tablets or the pediatric powder for oral solution, may substantially interfere with the absorption of quinolones, resulting in systemic concentrations considerably lower than desired. Therefore, AVELOX should be taken at least 4 hours before or 8 hours after these agents. [see DOSAGE AND ADMINISTRATION, Pharmacokinetics, and PATIENT INFORMATION.]

Warfarin

Quinolones, including AVELOX, have been reported to enhance the anticoagulant effects of warfarin or its derivatives in the patient population. In addition, infectious disease and its accompanying inflammatory process, age, and general status of the patient are risk factors for increased anticoagulant activity. Therefore the prothrombin time, International Normalized Ratio (INR), or other suitable anticoagulation tests should be closely monitored if a quinolone is administered concomitantly with warfarin or its derivatives. [see ADVERSE REACTIONS, Pharmacokinetics, and PATIENT INFORMATION.]

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)

Although not observed with AVELOX in preclinical and clinical trials, the concomitant administration of a nonsteroidal anti-inflammatory drug with a quinolone may increase the risks of CNS stimulation and convulsions [see WARNINGS AND PRECAUTIONS, and PATIENT INFORMATION].

Drugs that Prolong QT

There is limited information available on the potential for a pharmacodynamic interaction in humans between AVELOX and other drugs that prolong the QTc interval of the electrocardiogram. Sotalol, a Class III antiarrhythmic, has been shown to further increase the QTc interval when combined with high doses of intravenous (IV) AVELOX in dogs. Therefore, AVELOX should be avoided with Class IA and Class III antiarrhythmics. [see WARNINGS AND PRECAUTIONS, Nonclinical Toxicology, and PATIENT INFORMATION.]

Last reviewed on RxList: 10/27/2011
This monograph has been modified to include the generic and brand name in many instances.