Levofloxacin

Trade Names:Iquix- Solution, ophthalmic 1.5%

Trade Names:Levaquin- Tablets 250 mg- Tablets 500 mg- Tablets 750 mg- Solution, oral 25 mg/mL- Injection, solution, concentrate 500 mg (25 mg/mL)- Injection, solution, concentrate 750 mg (25 mg/mL)- Injection, solution (premix) 250 mg (5 mg/mL)- Injection, solution (premix) 500 mg (5 mg/mL)- Injection, solution (premix) 750 mg (5 mg/mL)

Trade Names:Quixin- Solution, ophthalmic 0.5% (5 mg/mL)

Pharmacology

Interferes with microbial DNA synthesis.

Pharmacokinetics

Absorption

T _max is 1 to 2 h. Food slightly prolongs T _max (1 h) and decreases C _max 14%. Can be administered with or without food. About 99% bioavailable. Steady state is reached within 48 h following 500 mg dose. C _max is 5.7 mcg/mL and C _min is 0.5 mcg/mL following multiple oral doses of 500 mg; for multiple doses of 750 mg, C _max is 8.6 mcg/mL and C _min is 1.1 mcg/mL.

Peak concentration decreased 25% when taken with food. Administer 1 h before or 2 h after eating.

C _max is about 6.2 mcg/mL after 500 mg dose infused over 60 min and about 11.5 mcg/mL after 750 mg dose infused over 90 min. Steady state is reached within 48 h following a once-daily (500 or 750 mg) regimen.

Oral and IV formulations are equivalent in AUC; therefore, route of administration is interchangeable.

Distribution

Vd is 74 to 112 L. Protein binding is approximately 24% to 38%.

Metabolism

Undergoes limited metabolism. Desmethyl and N-oxide, the only metabolites identified in humans, have little relevant pharmacological activity.

Elimination

Total body Cl is 144 to 226 mL/min. Renal Cl is 96 to 142 mL/min. Terminal half-life is 6 to 8 h.

Primarily excreted as unchanged drug in urine (87%), less than 4% in the feces.

Special Populations

Cl is reduced and half-life prolonged in patients with CrCl less than 50 mL/min. Dosage adjustment required. Hemodialysis and peritoneal dialysis do not remove levofloxacin from the body.

Pharmacokinetics not expected to be affected by hepatic function impairment.

Cl is increased in children 6 mo to 16 yr of age, resulting in lower plasma levels.

Indications and Usage

Treatment of acute bacterial exacerbation of chronic bronchitis, acute bacterial sinusitis, acute pyelonephritis, anthrax (inhalational, postexposure), chronic bacterial prostatitis, community-acquired pneumonia, complicated and uncomplicated skin and skin-structure infections, complicated and uncomplicated UTI, and nosocomial pneumonia caused by susceptible strains of specific microorganisms.

Treatment of conjunctivitis caused by susceptible strains of aerobic gram-positive and aerobic gram-negative microorganisms.

Unlabeled Uses

Disseminated gonococcal infections; traveler's diarrhea.

Contraindications

Hypersensitivity to fluoroquinolones, quinolone antibiotics, or any product component.

Dosage and Administration

PO / IV 500 mg every 24 h for 7 days.

PO / IV 500 mg every 24 h for 10 to 14 days or 750 mg every 24 h for 5 days.

PO/IV 500 mg every 24 h for 60 days.

PO 8 mg/kg (max, 250 mg/dose) every 12 h for 60 days.

PO / IV 500 mg every 24 h for 28 days.

PO / IV 500 mg every 24 h for 7 to 14 days, or 750 mg every 24 h for 5 days.

PO / IV

750 mg every 24 h for 5 days.

250 mg every 24 h for 10 days.

PO / IV 750 mg every 24 h for 7 to 14 days.

PO / IV 500 mg every 24 h for 7 to 10 days.

PO / IV 250 mg every 24 h for 3 days.

Topical Instill 1 to 2 drops in affected eye(s) every 2 h while awake, up to 8 times daily.

Topical Instill 1 to 2 drops in affected eye(s) every 4 h while awake, up to 4 times daily.

Topical Instill 1 to 2 drops in the affected eye(s) every 30 min to 2 h while awake and approximately 4 and 6 h after retiring.

Topical Instill 1 or 2 drops in the affected eye(s) every 1 to 4 h while awake.

General Advice

Oral and IV routes of administration are interchangeable on a mg-to-mg basis.

• Tablets
• Administer prescribed dose with a full glass of water.
• Administer without regard to meals, but administer with food if GI upset occurs.
• Administer levofloxacin 2 h before or after magnesium or aluminum antacids, sucralfate, iron supplement, multivitamin with minerals, or didanosine chewable/buffered tablets or oral solution.

• Oral solution
• Measure and administer prescribed dose using dosing cup.
• Administer prescribed dose on an empty stomach, 1 h before or 2 h after eating.

• Injection
• For IV administration only. Not for intradermal, subcutaneous, IM, intrathecal, or intraperitoneal administration.
• To prepare 250 mg dose, withdraw 10 mL and dilute with 40 mL of a compatible IV solution. To prepare 500 mg dose, withdraw 20 mL and dilute with 80 mL of a compatible IV solution. To prepare 750 mg dose, withdraw 30 mL and dilute with 120 mL of a compatible IV solution.
• Avoid rapid or bolus IV infusion. Infuse dose by slow IV infusion over 60 min (250 or 500 mg dose) or 90 min (750 mg dose) to prevent hypotensive reaction.
• Do not administer if particulate matter or discoloration is noted. A slight yellow to greenish-yellow color is normal.
• Do not coadminister with any solution containing multivalent cations (eg, magnesium) through the same IV line.
• Dilute single-use vial (concentrate) before use, following manufacturer's guidelines.
• Premix solution requires no further dilution and can be administered directly.
• Check premix IV container for minute leaks by squeezing bag firmly. If leaks are detected or the seal is not intact, discard solution because sterility may be impaired.
• Do not use premix containers in series to reduce risk of air embolism.
• Discard any unused IV solution.
• Do not add other medications or additives to IV container or infuse simultaneously through same IV line.
• Flush IV line with compatible IV fluid before and after levofloxacin infusion if same IV line is used for sequential infusion of different drugs.

• Ophthalmic solution
• For topical instillation into eye(s) only.
• Have patient tilt head back, pull lower lid out to make pocket, and instill medication into conjunctival sac. Have patient close eyes and apply light finger pressure to bridge of nose for 1 to 2 min. Advise patient to not blink or rub eyes.
• Do not touch top of dropper bottle to eye, fingers, or other surface.
• If using other topical ophthalmic drugs, separate each medication by at least 5 min.

Storage/Stability

Store at controlled room temperature (59° to 86°F).

Store injection concentrate at controlled room temperature (59° to 86°F). Protect from light. Reconstituted injection is stable for 72 h when stored at or below 77°F, for 14 days if refrigerated at 41°F in plastic IV containers, or for 6 mo if frozen (−4°F). Thaw frozen container at room temperature (77°F) or under refrigeration (46°F). Do not force thawing by immersion in water or by microwave irradiation. Do not refreeze after initial thawing. Store premix at or below 77°F. Brief exposure up to 104°F does not adversely affect the product. Avoid excessive heat, and protect from freezing and light.

Store at 59° to 77°F. Protect from freezing. Keep container tightly closed.

Drug Interactions

May decrease oral absorption of levofloxacin. Stagger administration times by at least 2 h.

Because of increased risk of life-threatening cardiac arrhythmias, including torsades de pointes, avoid coadministration of levofloxacin.

Hyperglycemia or hypoglycemia may occur.

Antineoplastic agents may decrease levofloxacin absorption by altering the intestinal mucosa.

Risk of life-threatening cardiac arrhythmias may be increased.

May increase risk of CNS stimulation and convulsive seizures.

May increase bleeding.

Laboratory Test Interactions

May produce false-positive urine screening results for opiates using commercially available immunoassay kits.

Adverse Reactions

Cardiovascular

Prolonged QT interval, tachycardia, torsades de pointes, vasodilatation (postmarketing).

CNS

Headache (6%); insomnia (4%); dizziness (3%); abnormal EEG, ageusia, anosmia, dysgeusia, dysphonia, encephalopathy, paranoia, parosmia, peripheral neuropathy, psychosis, suicide attempts and ideation (postmarketing).

Headache (8% to 10%).

Dermatologic

Rash (2%); pruritus (1%); bullous eruptions, including erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis; leukocytoclastic vasculitis; photosensitivity; phototoxicity (postmarketing).

EENT

Blurred vision, hypoacusis, reduced visual acuity, scotoma, tinnitus, visual disturbances including diplopia (postmarketing).

Decreased/blurred vision, foreign body sensation, installation-site irritation/discomfort, ocular infection, ocular pain, pharyngitis, photophobia, throat irritation, transient ocular burning or discomfort (1% to 3%).

GI

Nausea (7%); diarrhea (5%); constipation (3%); abdominal pain, dyspepsia, vomiting (2%).

Taste disturbance (8% to 10%); diarrhea, dyspepsia, nausea (1% to 2%).

Genitourinary

Vaginitis (1%); interstitial nephritis (postmarketing).

Hematologic-Lymphatic

Aplastic anemia, eosinophilia, hemolytic anemia, leukopenia, pancytopenia (postmarketing).

Hepatic

Hepatic failure, hepatitis, jaundice (postmarketing).

Hypersensitivity

Hypersensitivity reactions, sometimes fatal, including anaphylactic/anaphylactoid reactions, anaphylactic shock, angioneurotic edema, and serum sickness (postmarketing).

Lab Tests

Increased muscle enzymes, prolonged INR and PT (postmarketing).

Local

Injection-site reaction (1%).

Musculoskeletal

Muscle injury and rupture, rhabdomyolysis, tendon rupture (postmarketing).

Respiratory

Dyspnea (1%); allergic pneumonitis (postmarketing).

Miscellaneous

Edema, chest pain, moniliasis (1%); multiorgan failure, pyrexia (postmarketing).

Fever, infection (1% to 3%).

Precautions

Pregnancy

Category C .

Lactation

Undetermined; however, other drugs in this class are excreted in breast milk.

Children

Except for inhalational anthrax (postexposure), safety and efficacy have not been established in children.

Safety and efficacy not established in children younger than 6 mo of age.

Safety and efficacy not established in children younger than 1 yr of age.

Elderly

Elderly patients are at increased risk for developing severe tendon disorder and severe and sometimes fatal hepatotoxicity. In addition, because elderly patients are more likely to have decreased renal function, use caution in dose selection and consider monitoring renal function.

Hypersensitivity

Serious and potentially fatal reactions have occurred with drugs in this class. Discontinue drug if allergic reaction occurs.

Renal Function

Reduced Cl may occur; adjust dose downward accordingly in CrCl less than 50 mL/min. Refer to manufacturer's package insert for dose calculations.

Superinfection

Prolonged use may result in overgrowth of nonsusceptible organisms.

Photosensitivity

Moderate to severe reactions may occur; avoid excessive sunlight and ultraviolet light.

Arrhythmia

Levofloxacin has been associated with prolonged QT interval and infrequent cases of arrhythmia. Avoid in patients with known prolongation of QT interval or uncorrected hypokalemia, and in patients receiving class IA or III antiarrhythmic agents.

Blood glucose

Disturbances of blood glucose, including symptomatic hyperglycemia and hypoglycemia, have been reported, usually in patients with diabetes receiving an oral hypoglycemic agent or insulin.

CNS effects

CNS stimulation can occur; use drug with caution in patients with known or suspected CNS disorders (eg, seizure disorders, psychoses).

Hepatotoxicity

Severe hepatotoxicity, including acute hepatitis and fatal events, has been reported during postmarketing experience.

Musculoskeletal disorders

Compared with controls, pediatric patients have experienced an increased incidence of musculoskeletal disorders (eg, arthralgia, arthritis, gait abnormalities, tendonopathy).

Peripheral neuropathy

Rare cases resulting in dysesthesias, hypesthesias, paresthesias, and weakness have been reported.

Pseudomembranous colitis

Consider possibility in patients who develop diarrhea.

Serious reactions

Clinical manifestations of serious and sometimes fatal reactions that have been reported with levofloxacin include acute hepatic necrosis or failure, acute renal insufficiency or failure, agranulocytosis, allergic pneumonitis, anemia (including hemolytic and aplastic), arthralgia, fever, hepatitis, interstitial nephritis, jaundice, leukopenia, myalgia, pancytopenia, rash, serum sickness, Stevens-Johnson syndrome, thrombocytopenia (including thrombotic thrombocytopenic purpura), toxic epidermal necrolysis, and vasculitis.

Overdosage

Symptoms

Low potential for acute toxicity.

Patient Information

• Review dosing schedule and prescribed length of therapy with patient.
• Remind patient that levofloxacin is an antibiotic that should only be used to treat bacterial infections and does not treat viral infections (eg, common cold).
• Reinforce to patient or caregiver the need to take exactly as prescribed and complete the entire course of therapy, even if symptoms of infection have disappeared. Caution patient or caregiver that skipping doses or not completing the full course of therapy may allow the infection to worsen, and increases the possibility that bacteria will become resistant to the antibiotic and may cause infections that will not be treatable in the future.
• Advise patient to contact health care provider if infection does not improve or worsens.
• Advise patient to drink fluids liberally (eg, eight 8 oz glasses of water daily) while taking this medication.
• Advise patient to discontinue therapy and contact health care provider immediately if any of the following occur: anxiety; confusion; depression; fainting; hallucinations; hives; insomnia; itching; light-headedness; nightmares; pain, tenderness, or rupture of tendon; palpitations; paranoia; restlessness; seizure; shortness of breath; skin rash; suicidal thoughts or acts; swelling of the lips, tongue, or face; tremors; or symptoms of neuropathy (eg, burning, numbness, pain, tingling, weakness, other alterations of sensation).
• Instruct diabetic patient using insulin or oral hypoglycemic agents to monitor blood glucose more frequently when drug is started and to inform health care provider of significant changes in readings. Advise patient that if a hypoglycemic event occurs to discontinue levofloxacin immediately, treat the hypoglycemia and notify health care provider.
• Warn patient that diarrhea containing blood or pus may be a sign of a serious disorder and to seek medical care if noted and not to treat at home.
• Caution patient that drug may cause dizziness or light-headedness and to use caution while driving or performing other tasks requiring mental alertness until tolerance is determined.
• Advise patient to avoid unnecessary exposure to sunlight or tanning lamps, and to use sunscreen and wear protective clothing to avoid photosensitivity reactions.

• Oral
• Advise patient or caregiver to read the patient information leaflet before starting therapy.
• Instruct patient to take tablets with a full glass of water without regard to meals. Advise patient to take with food if stomach upset occurs.
• Instruct patient using oral solution to measure and administer prescribed dose using dosing cup.
• Instruct patient using oral solution to take prescribed dose on an empty stomach 1 h before or 2 h after eating.
• Instruct patient to take levofloxacin 2 h before or after aluminum or magnesium antacids, iron supplements, multivitamins with minerals, sucralfate, or didanosine chewable/buffered tablets or oral solution.

• Injection
• Explain to patient or caregiver that medication usually is prepared and administered by health care provider in a health care setting, but may be used at home if ordered by the patient's health care provider.
• If patient or caregiver is administering at home, ensure that the patient or caregiver understands how to store, prepare, and administer the dose, and dispose of used equipment and supplies. Perform first injection with the supervision of a qualified health care provider.
• Advise patient to contact health care provider if injection-site reaction occurs.

• Ophthalmic
• Remind patient not to wear contact lenses if experiencing signs and symptoms of bacterial conjunctivitis.
• Teach patient the following proper technique for instilling eye drops: wash hands; do not allow dropper to touch eye. Tilt head back, look up and pull lower eyelid down and instill prescribed number of drops. Close eye for 1 to 2 min and apply gentle pressure to bridge of nose. Do not rub eye.
• Advise patient not to touch top of dropper bottle to eye, fingers, or other surface.
• Advise patient that if more than 1 topical ophthalmic drug is being used, administer the drugs at least 5 min apart.
• Advise patient to inform health care provider if ocular adverse reactions occur and become bothersome or if infection is not improving.

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