moxifloxacin (Rx)

Brand and Other Names:Avelox, Moxifloxacin Systemic
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Dosing & Uses


Dosage Forms & Strengths

injectable solution

  • 400mg/250mL


  • 400mg

Acute Bacterial Sinusitis

400 mg PO/IV qDay for 5-10 days

Limitations-of-use: Reserve fluoroquinolones for patients who do not have other available treatment options for acute sinusitis

Community-Acquired Pneumonia

400 mg PO/IV qDay for 7-14 days

Acute Exacerbation of Chronic Bronchitis

Indicated for acute exacerbations of chronic bronchitis caused by bacterial infections

400 mg PO/IV qDay for 5 days

Limitations-of-use: Reserve fluoroquinolones for patients who do not have other available treatment options for acute bacterial exacerbation of chronic bronchitis

Skin & Skin Structure Infections

Uncomplicated: 400 mg PO/IV qDay for 7 days

Complicated: 400 mg PO/IV qDay for 7-21 days

Intra-abdominal Infections

Complicated: 400 mg PO/IV qDay for 5-14 days

Pneumonic & Septicemic Plague

Indicated in adults for the treatment of plague, including pneumonic and septicemic plague, caused by susceptible isolates of Yersinia pestis; it is also indicated for prophylaxis of plague in adults

400 mg PO/IV qDay x10-14 days

Begin administration as soon as possible after suspected or confirmed exposure to Yersinia pestis

Dosing Considerations

Initial IV administration may be changed to PO administration at same dosage to complete therapy, depending on patient's clinical status

Susceptible organisms

  • Aeromonas hydrophila, Bacillus anthracis, Bacteroides fragilis, Bacteroides thetaiotaomicron, Campylobacter jejuni, Citrobacter diversus, Citrobacter freundii, Clostridium perfringens, Escherichia coli, Enterobacter spp, Haemophilus influenzae, Hafnia alvei, Klebsiella pneumoniae, Legionella pneumophila, Morganella morganii, Moraxella catarrhalis, Mycobacterium pneumoniae, Mycobacterium tuberculosis, Neisseria gonorrhoeae, Peptostreptococcus spp, Proteus mirabilis, Proteus vulgaris, Providencia spp, Pseudomonas aeruginosa, Salmonella typhi, Shigella spp, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus anginosus, Streptococcus constellatus, Streptococcus pneumoniae, Vibrio cholerae, Yersinia pestis
  • First-line therapy: C jejuni; no unanimity on others (eg, L pneumophila, M morganii)

<18 years: Safety and efficacy not established



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            Adverse Effects


            Nausea (7%)

            Diarrhea (6%)

            Dizziness (3%)

            Decreased amylase (2%)

            Decreased basophils, eosinophils, hemoglobin, prothrombin time, red blood cells, neutrophils (2%)

            Decreased serum glucose (2%)

            Increased serum chloride (2%)

            Increased serum ionized calcium (2%)

            Immune hypersensitivity reaction (0.1-2%)

            Prolonged QT interval (0.1-2%)


            Acute renal failure


            Anaphylactoid reaction

            Aplastic anemia

            Extrinsic allergic alveolitis

            Hemolytic anemia

            Hepatic failure

            Hepatic necrosis




            Serum sickness due to drug

            Stevens-Johnson syndrome

            Tendon rupture, tendinitis


            Torsades de pointes

            Toxic epidermal necrolysis

            Postmarketing Reports

            Blood and lymphatic disorders: Agranulocytosis, pancytopenia

            Cardiovascular disorders: Ventricular tachyarrhythmias (including in very rare cases cardiac arrest and torsade de pointes)

            Ear and labyrinth disorders: Hearing impairment, including deafness (reversible in most cases)

            Eye disorders: Vision loss (especially in the course of CNS reactions, transient in majority of cases)

            Hepatobiliary disorders: Hepatitis, hepatic failure, jaundice, acute hepatic necrosis

            Immune system disorders: Anaphylactic reactions including shock, angioedema (including laryngeal edema)

            Musculoskeletal/connective tissue disorders: Tendon rupture, arthralgia, myalgia

            Nervous system disorders: Exacerbation of myasthenia gravis symptoms, altered coordination, abnormal gait, muscle weakness, peripheral neuropathy, polyneuropathy

            Central nervous system effects: Hallucinations, anxiety, depression, insomnia, severe headaches, and confusion

            Psychiatric disorders: Psychotic reaction (very rarely culminating in self-injurious behavior, such as suicidal ideation/thoughts or suicide attempts)

            Renal and urinary disorders: Renal dysfunction, interstitial nephritis

            Respiratory disorders: Allergic pneumonitis

            Skin and tissue disorders: Photosensitivity/phototoxicity reaction, Stevens-Johnson syndrome, Toxic epidermal necrolysis



            Black Box Warnings

            Fluoroquinolones have been associated with disabling and potentially irreversible serious adverse reactions that have occurred together including: tendinitis and tendon rupture, peripheral neuropathy, and CNS effects

            Discontinue the drug immediately and avoid use of systemic fluoroquinolones in patients who experience any of these serious adverse reactions

            May exacerbate muscle weakness in patients with myasthenia gravis; fluoroquinolones should be avoided in patients with known history of myasthenia gravis

            Serious adverse effects and limitations-of-use

            • Both oral and injectable fluoroquinolones are associated with disabling side effects involving tendons, muscles, joints, nerves and the central nervous system
            • These side effects can occur hours to weeks after exposure to fluoroquinolones and may potentially be permanent
            • Because the risk of these serious side effects generally outweighs the benefits for patients with acute bacterial sinusitis, acute exacerbation of chronic bronchitis, and uncomplicated UTIs, that fluoroquinolones should be reserved for use in patients with these conditions who have no alternative treatment options
            • For some serious bacterial infections, including anthrax, plague, and bacterial pneumonia among others, the benefits of fluoroquinolones outweigh the risks and it is appropriate for them to remain available as a therapeutic option


            Hyersensitivity to drug or component


            In prolonged therapy, perform periodic evaluations of organ system function (eg, renal, hepatic, hematopoietic); superinfections may occur with prolonged or repeated antibiotic therapy

            Phototoxicity reactions may occur; avoid excessive sunlight

            Use caution in cardiovascular disease especially significant bradycardia or acute myocardial ischemia

            Peripheral neuropathy: Sensory or sensorimotor axonal polyneuropathy affecting small and/or large axons resulting in paresthesias, hypoesthesias, dysesthesias, and weakness reported; peripheral neuropathy may occur rapidly after initiating and may potentially become permanent

            Serious, sometimes fatal hypogycemia reported including in patients without a history of hypoglycemia (common with gatifloxacin, which is no longer marketed); monitor glucose levels closely in patients with diabetes; if hypoglycemic reaction occurs, discontinue therapy and initiate appropriate therapy immediately

            Fulminant hepatitis, potentially leading to liver failure reported; discontinue treatment if hepatitis symptoms occur

            Commonly seen adverse reactions include tendinitis, tendon rupture, arthralgia, myalgia, peripheral neuropathy, and central nervous system effects (hallucinations, anxiety, depression, insomnia, severe headaches, and confusion); these reactions can occur within hours to weeks after starting therapy, including in patients of any age or without pre-existing risk factors; discontinue therapy immediately at first signs or symptoms of any serious adverse reaction; in addition, avoid use of fluoroquinolones, in patients who have experienced any serious adverse reactions associated with fluoroquinolones

            Risk of developing fluoroquinolone-associated tendinitis and tendon rupture is increased in patients over 60 years of age, in patients taking corticosteroid drugs, and in patients with kidney, heart or lung transplants; other factors that may independently increase risk of tendon rupture include strenuous physical activity, renal failure, and previous tendon disorders such as rheumatoid arthritis

            Avoid use in presence of drugs or conditions that prolong QT interval, uncorrected hypomagnesemia or hypokalemia

            Hallucinations, convulsions, and increased intracranial pressure (including pseudotumor cerebri) and toxic psychosis reported

            Acute onset of retinal detachment increased 4.5-fold with oral fluoroquinolones in a single case-controlled study - JAMA 2012;307(13):1414-1419; another study disputes these findings (relative risk, 1.29) - JAMA 2013;310(20):2184-2190

            Use caution in patients with a history of diabetes, hepatic impairment, renal impairment, or rheumatoid arthrtitis

            As with all fluoroquinolones, disturbances in blood glucose, including both hypoglycemia and hyperglycemia have been reported in diabetic patients; monitor blood glucose

            Prescribing antibiotics in absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to patient and increases risk of development of drug-resistant bacteria

            Clostridium difficile-associated diarrhea (CDAD) has been reported; if CDAD suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued; appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated


            Pregnancy & Lactation


            There are no available human data establishing a drug associated risk; however, when moxifloxacin was administered to rats during pregnancy and throughout lactation at doses associated with maternal toxicity, decreased neonatal body weights, increased incidence of skeletal variations (rib and vertebra combined), and increased fetal loss were observed

            Advise pregnant women of potential risk to fetus


            Not known if moxifloxacin is present in human milk

            Based on animal studies in rats, moxifloxacin may be excreted in human milk

            Developmental and health benefits of breastfeeding should be considered along with mother’s clinical need for therapy and any potential adverse effects on the breastfed child from drug or from the underlying maternal condition

            Pregnancy Categories

            A:Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

            B:May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

            C:Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

            D:Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

            X:Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

            NA:Information not available.



            Mechanism of Action

            Inhibits A subunits of DNA gyrase, resulting in inhibition of bacterial DNA replication and transcription


            Well absorbed; absorption is not affected by high-fat meal or yogurt

            Bioavailability: 90%


            Protein bound: 50%

            Vd: 1.7-2.7 L/kg; tissue concentrations often exceed plasma concentrations in respiratory tissues, alveolar macrophages, and sinus tissues


            Metabolized in liver via glucuronide (14%) and sulfate (38%) conjugation


            Half-life: PO, 12 hr; IV, 15 hr

            Excretion: Feces (25%), urine (20% as unchanged drug)

            Sulfate conjugate metabolites are excreted in feces, glucuronide conjugate metabolites in urine



            IV Preparation

            No further dilution of infusion solution is necessary

            IV Administration

            Infuse over 1 hour

            Do not admix with other drugs or infuse through same tubing simultaneously





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            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
            4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
            QL Quantity Limits
            Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
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            Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
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            Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.