Gatifloxacin Ophthalmic Solution - Uses and Side Effects

Overview

Gatifloxacin is an antibiotic and belongs to the fourth-generation fluoroquinolone family. Bristol-Myers Squibb first introduced it in 1999 for treating respiratory tract infections. It prevents the bacterial enzymes from topoisomerase IV and DNA gyrase. Gatifloxacin is available as a tablet and solution for intravenous therapy. It is also used as an eye drop for treating bacterial infections.

How Does Gatifloxacin Ophthalmic Solution Work?

The bactericidal action of Gatifloxacin is due to the inhibition of the enzymes topoisomerase II (DNA gyrase) and topoisomerase IV, which are required for bacterial DNA replication, transcription, repair, and recombination.

Uses of Gatifloxacin Ophthalmic Solution

Gatifloxacin is indicated for the treatment of bacterial conjunctivitis caused by the strains of the following bacteria:

• Aerobic Gram-positive Bacteria: Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus mitis group, Streptococcus oralis, and Streptococcus pneumonia.

• Aerobic Gram-negative Bacteria: Hemophilus influenzae.

Dosage Restrictions:

1. Route of Administration - Eye drop.

2. Dosage Strengths - 0.5 percent Gatifloxacin.

3. Dosage Form - Ophthalmic solution.

Special Considerations:

Pregnancy:

There is not much data available on the effect of Gatifloxacin on pregnant women or on the fetus.

Lactation:

There needs to be more information regarding the presence of Gatifloxacin in human milk, its effect on breastfed infants, or milk production. However, systemic levels of Gatifloxacin after topical ocular administration are low, and whether the drug would be present in maternal milk is not known.

Pediatric:

The safety of Gatifloxacin in infants below one year of age has yet to be established. Gatifloxacin has been found to be safe and effective for treating bacterial conjunctivitis in pediatric patients one year or older.

Geriatric:

No difference in safety or effectiveness has been observed between the elderly and younger individuals.

Warnings and Contraindications

Gatifloxacin is contraindicated in individuals with a hypersensitivity to Gatifloxacin, other Quinolones, or any of the components of the medicine.

Warnings and Precautions:

• Hypersensitivity - Certain individuals receiving ophthalmic Gatifloxacin have been found to show hypersensitivity reactions such as anaphylaxis, angioedema (including pharyngeal, laryngeal, or facial edema), dyspnea, urticaria, and itching, with a single dose. Stevens-Johnson syndrome has also been reported with the use of Gatifloxacin eye drops. The drug should be discontinued in case of an allergic reaction.

• Growth of Resistant Organisms - Prolonged usage of Gatifloxacin results in the overgrowth of nonsusceptible organisms, including fungi. In case of superinfections, the drug should be discontinued.

• Corneal Endothelial Cell Injury - Gatifloxacin is used as a topical eye drop. It might cause corneal endothelial cell injury if introduced directly into the eye's anterior chamber.

For Patients

What Is Eye Infection?

Eye infections can occur in various parts of the eye, affecting one or both eyes. Bacteria, fungi, or viruses can cause eye infections.

Two common eye infections are:

Conjunctivitis - Conjunctivitis is also known as pink eye. Conjunctivitis is an eye infection that occurs due to a bacterial infection. Children frequently catch it, and it is very contagious.

Stye - A bump on the eyelid happens when bacteria from the skin gets into the hair follicle of an eyelash.

The symptoms of eye infections include redness, itching, swelling, discharge, pain, or problems with vision. Treatment is symptomatic and depends on the infection cause, and may include compresses, eye drops, creams, or antibiotics.

Why Is Gatifloxacin Ophthalmic Solution Prescribed for Eye Infection?

Gatifloxacin ophthalmic solution is prescribed to treat bacterial infections like conjunctivitis or pinkeye in adults and kids of one year of age or older. Conjunctivitis is an infection of the membrane that covers the outside of the eyeballs and the inside of the eyelids. Gatifloxacin belongs to a group of antibiotics called fluoroquinolones, which works by killing the bacteria that cause the infection.

Facts One Should Know About Gatifloxacin Ophthalmic Solution:

How Should One Take Gatifloxacin Ophthalmic Solution?

• Gatifloxacin is an ophthalmic solution that should be instilled in the eyes. It is instilled every two hours while awake (up to eight times a day) for two days and then two to four times a day for five days.

• Gatifloxacin eye drops should be instilled at around the same time every day.

• The directions on the prescription should be followed properly.

• Gatifloxacin ophthalmic solution should be used as directed. No more or less of it, or use it more often than the doctor prescribes.

• One should expect the symptoms to improve during treatment.

• If the symptoms do not go away or become worse, or if the person develops other eye problems during treatment, the doctor should be informed immediately.

• The Gatifloxacin eye drops should be continued until one finishes the prescription.

• If one stops using Gatifloxacin eye drops too soon, the infection may not be completely cured, and the bacteria might become resistant to antibiotics.

What To Discuss With The Doctor Before Starting Gatifloxacin Ophthalmic Solution?

• The doctor should be informed in case of allergy to Gatifloxacin or other quinolone antibiotics.

• Inform the doctor about the other prescription and non-prescription medications, nutritional supplements, vitamins, and herbal products one is taking. The following drugs should be mentioned if taken, anticoagulants, Cyclosporine, and Theophylline.

• Inform the doctor if one has or ever has any medical condition.

• Inform the doctor if one is pregnant, plans to conceive, or is breastfeeding.

• Inform the doctor in case one is wearing contact lenses. One should abstain from wearing contact lenses in case of bacterial conjunctivitis or during the application of eye drops.

• Bacterial conjunctivitis is a contagious disease. Hence, hands should be washed often, especially after touching the eyes. Once the infection subsides, any eye makeup, contact lenses, or other objects that touch your infected eyes should be washed properly or replaced.

Is Gatifloxacin Ophthalmic Solution Safe?

Yes, Gatifloxacin is quite safe if taken within the prescribed dosage.

Is Gatifloxacin Ophthalmic Solution Effective?

Gatifloxacin effectively treats bacterial conjunctivitis if used according to the prescribed dosage.

What Side Effects Can You Expect With Gatifloxacin Ophthalmic Solution?

One may experience the following side effects with Gatifloxacin:

• Reddish, irritated, itchy, or watery eyes.

• Eye pain.

• Swollen eyelids.

• Blurred vision.

• Eye discharge.

• Broken blood vessels in the eyes.

• Unpleasant taste.

• Headache.

Serious side effects may include the following:

• Difficulty in breathing or swallowing.

• Rashes.

• Itching.

• Hives.

• Swelling of the tongue, face, throat, lips, eyes, hands, feet, ankles, or lower legs.

• Hoarseness of voice.

Can One Stop Taking Gatifloxacin Ophthalmic Solution Without The Doctor's Approval?

Instill the eye drops as prescribed by the doctor, and do not stop them without the doctor's consent.

Are There Any Dietary Restrictions While Taking Gatifloxacin Ophthalmic Solution?

Inform the doctor about drinking coffee or other caffeinated beverages while on this medication.

How Should One Store Gatifloxacin Ophthalmic Solution?

The medication should be kept in a tightly closed container and out of reach of children. It should be stored in the bathroom at room temperature and away from moisture and heat. The medicine should not be allowed to freeze.

How Should One Dispose of Gatifloxacin Ophthalmic Solution?

Unused or expired medications should be disposed of in ways so that pets, kids, and other people cannot consume them. However, it should not be flushed down the toilet. The best way to get rid of the medication is through a medicine take-back program by contacting the local garbage or recycling department to learn about take-back programs in the community.

For Doctors

Indications:

Gatifloxacin is indicated for the treatment of bacterial conjunctivitis caused by the strains of the following bacteria:

Aerobic Gram-positive Bacteria: Staphylococcus epidermidis, Staphylococcus aureus

Streptococcus mitis group, Streptococcus oralis, and Streptococcus pneumoniae.

Aerobic Gram-negative Bacteria: Haemophilus influenzae.

What Is the Pharmacology of Gatifloxacin Ophthalmic Solution?

Description:

Gatifloxacin is a quinolone antimicrobial ophthalmic solution used to treat bacterial conjunctivitis. Its chemical name is (+_) -1-Cyclopropyl-6-fluoro-1,4-dihydro-8­ methoxy-7-(3-methyl-1-piperazinyl)-4-oxo-3-quinoline carboxylic acid, sesquihydrate. The molecular formula is C19H22FN3O4.1 1/2 H2O, and its molecular weight is 402.42.

Components

Active Ingredients - Gatifloxacin 0.5 percent.

Inactive Ingredients

• Benzalkonium chloride 0.005 percent.

• Edetate disodium.

• Sodium chloride.

• Purified water.

• Hydrochloric acid and sodium hydroxide adjust the pH.

Clinical Pharmacology:

Mechanism of Action

Gatifloxacin belongs to the quinolone group of antimicrobials. Gatifloxacin is an 8-methoxy fluoroquinolone with a 3-methyl piperazinyl substituent at C7. Gatifloxacin acts as an antibacterial by inhibiting topoisomerase IV and DNA gyrase. DNA gyrase is an important enzyme in bacterial DNA's transcription, replication, and repair. The enzyme topoisomerase IV plays an important role in chromosomal DNA partitioning during bacterial cell division.

The mechanism of action of Gatifloxacin is different from that of aminoglycoside, tetracycline antibiotics, and macrolide. Thus making Gatifloxacin active against the organisms resistant to these antibiotics, which in turn are active against the organisms resistant to Gatifloxacin. There is no cross-resistance between these antibiotics and Gatifloxacin. Cross-resistance has been found to occur between Gatifloxacin and a few other Fluoroquinolones.

Pharmacodynamics

Gatifloxacin is a broad-spectrum 8-methoxyfluoroquinolone antibacterial that is used for oral as well as intravenous administration. Gatifloxacin's mechanism of action depends on blocking bacterial DNA's replication by self-binding to an enzyme DNA gyrase, which causes the untwisting to replicate one DNA double helix into two helixes. Gatifloxacin has a higher affinity for the bacterial DNA gyrase as compared to the mammalian. Gatifloxacin is a broad-spectrum antibiotic and is active against both Gram-negative and Gram-positive bacteria. It should be specifically used to prevent or treat bacterial infections.

Pharmacokinetics

Mean Cmax - 3.2 to 3.8 μg/ml.

Median Tmax - 1.3 to 1.8 hours.

[Cmax - Cmax is the maximum concentration achieved by a drug in the blood, cerebrospinal fluid, or target organ after administration of a dose]

[Tmax - Tmax is the time taken for a drug to reach maximum concentration after administration of a dose]

Gatifloxacin, 0.5 percent solution, was administered to each eye of six healthy males in a dosing regimen beginning with a single two-drop dose, then two drops four times daily for seven days, and finally two drops eight times daily for three days. The serum Gatifloxacin levels all through were below the lower limit in all the individuals.

Metabolism:

Gatifloxacin undergoes much less biotransformation in humans, with less than one percent of the dosage excreted in the urine as methyl ethylene diamine and ethylenediamine metabolites.

Special Considerations

Pediatric:

The safety of Gatifloxacin in infants below one year of age has yet to be established. Gatifloxacin has been found to be safe and effective for treating bacterial conjunctivitis in pediatric patients one year or older.

Geriatric:

No difference in safety or effectiveness has been observed between the elderly and younger individuals.

Pregnancy:

There is not much data available on the effect of Gatifloxacin on pregnant women or the fetus.

Lactation:

There needs to be more information regarding the presence of Gatifloxacin in human milk, its effect on breastfed infants, or milk production. However, systemic levels of Gatifloxacin after topical ocular administration are low, and whether the drug would be present in maternal milk is not known.

Drug Interactions:

• Aceclofenac - The neuroexcitatory of Gatifloxacin may be increased when combined with Aceclofenac.

• Acetaminophen - Gatifloxacin, when combined with Acetaminophen, can decrease its metabolism.

• Albendazole - Gatifloxacin decreases the metabolism of Albendazole when combined with it.

• Benzylpenicillin - The concentration of Gatifloxacin is increased in combination with Benzylpenicillin.

What Have Clinical Trials Shown About Gatifloxacin Ophthalmic Solution?

In two randomized, multicenter, double-masked clinical trials, patients from the age group range of 1 to 89 years were given Gatifloxacin for five days. The drug was found to be good on day six in people with conjunctivitis and positive conjunctival cultures.

Results - Clinical results for the trials demonstrated success in 58 percent of individuals for the Gatifloxacin-treated groups versus 45 percent for the vehicle-treated groups. Microbiological results for the same clinical trials showed a statistically better rate of eradication of 90 percent for Gatifloxacin versus 70 percent for the vehicle.

Patient Counseling Information:

Administration Instructions

• The individual should be advised not to touch the tip of the bottle to avoid the product.

• The drug can lead to hypersensitivity reactions. So, the individuals should be advised to discontinue its use immediately and inform the doctor at the first sign of a hypersensitivity reaction such as rash, etc.

• Before instilling the eye drops, the hands should be thoroughly washed with soap and water.

• The tip of the dropper should not be chipped or cracked.

• The tip of the dropper should not touch the eye or anything else and should be kept clean.

• After tilting the head back, the eye's lower lid should be pulled down with the index finger to form a pocket.

• The dropper should be held with the other hand close to the eye without touching it.

• Squeeze the dropper gently so that one drop falls into the pocket made by the lower eyelid.

• Close the eye for two to three minutes.

• Do not squeeze or blink the eyelids.

• Apply gentle pressure on the tear duct.

• Wipe off any excess medicine.

• If more than one drop is used in the same eye, wait for five minutes before instilling the next one.

• Replace the cap on the bottle.

• Do not rinse or wipe the dropper tip.

• The hands should be washed thoroughly after each use.

Complications or Side Effects

• Increased tears.

• Irritation of the conjunctiva.

• Keratitis.

• Conjunctival hemorrhage.

• Papillary conjunctivitis.

• Chemosis.

• Dry eye.

• Discharge from the eyes.

• Eye irritation.

• Eye pain.

• Swelling of the eyelid.

• Red eye.

• Decrease in visual acuity.

• Change in taste.