Ofloxacin

Ofloxacin is a fluoroquinolone antibiotic available in three distinct forms — ear drops, eye drops, and oral tablets — each approved for different bacterial infections.

• Ofloxacin otic solution (ear drops): Treats outer ear infections (otitis externa) in adults and children 6 months and older; chronic middle ear infections with a perforated eardrum in patients 12 and older; and acute middle ear infections in children 1–12 years old who have ear tubes (tympanostomy tubes)
• Ofloxacin ophthalmic solution (eye drops), including Ocuflox: Treats bacterial conjunctivitis (pink eye) and bacterial corneal ulcers in adults
• Ofloxacin oral tablets: Treats adults with community-acquired pneumonia; uncomplicated skin and skin structure infections; acute gonorrhea; nongonococcal urethritis or cervicitis due to chlamydia; mixed urethral/cervical infections; and acute pelvic inflammatory disease. Also approved for acute bacterial exacerbations of chronic bronchitis and uncomplicated cystitis, but only when no alternative antibiotics are available, due to serious safety concerns

Ofloxacin is a fluoroquinolone antibiotic. It kills bacteria by blocking two enzymes they depend on — DNA gyrase and topoisomerase IV — that bacteria need to replicate, transcribe, and repair their DNA. When these enzymes are blocked, bacteria can't multiply or survive. This mechanism makes ofloxacin effective against a wide variety of both gram-positive and gram-negative bacteria.

Because ofloxacin targets bacterial enzymes that human cells don't use the same way, it can fight infection with relatively selective action. However, resistance can develop, so it should only be used for infections proven or strongly suspected to be caused by susceptible bacteria — not as a first-line option when safer alternatives exist.

Ofloxacin comes in three forms and each is used very differently — they are not interchangeable.

• Ear drops (otic solution): Instilled once or twice daily into the affected ear for a set number of days, depending on the condition and patient age. Warm the bottle in your hand for 1–2 minutes before use, then lie with the ear facing up and remain in that position for 5 minutes after instillation.
• Eye drops (ophthalmic solution): Instilled into the affected eye with a frequency that starts more often (every 30 minutes to a few hours) in the first day or two, then tapers to several times daily as the infection improves. Follow the exact schedule your doctor gives you.
• Oral tablets: Generally taken twice a day (every 12 hours); food does not reduce absorption, though it may slightly delay it. Patients with kidney problems may need a lower dose or adjusted schedule — your prescriber will determine this. Do not take antacids, iron, zinc, or similar supplements within 2 hours before or after a tablet dose.

The most commonly reported side effects with ofloxacin tablets and intravenous use include:

• Nausea and vomiting
• Diarrhea
• Headache
• Dizziness
• Insomnia (trouble sleeping)
• Rash or itching
• Vaginal itching or vaginitis
• Altered taste

Serious reactions — including tendon rupture, permanent nerve damage, severe allergic reactions, seizures, psychotic symptoms, dangerous blood sugar swings, and a severe gut infection called C. difficile colitis — require you to stop the medication immediately and seek medical attention. These can occur even in people without known risk factors.

• Tendon damage: Ofloxacin can cause tendinitis (tendon inflammation) and tendon rupture, most often in the Achilles tendon. This can happen within hours of starting the drug or months after stopping it. Risk is highest in adults over 60, people on corticosteroids, and those who have had a kidney, heart, or lung transplant. Stop immediately at the first sign of tendon pain or swelling.
• Nerve damage (peripheral neuropathy): Ofloxacin can cause numbness, tingling, burning, or weakness in the arms or legs. This damage may be irreversible. Stop the drug immediately if these symptoms appear.
• Central nervous system effects: Seizures, hallucinations, confusion, severe depression, and suicidal thoughts have been reported. Use with extreme caution in anyone with epilepsy or other brain/nervous system conditions.
• Myasthenia gravis: Ofloxacin must not be used in people with myasthenia gravis — it can cause severe, potentially fatal worsening of muscle weakness.
• Severe allergic reactions: Anaphylaxis (a life-threatening allergic reaction) can occur after even the first dose. Stop the medication and get emergency help for facial swelling, throat tightness, or difficulty breathing.
• C. difficile colitis: Antibiotic use, including ofloxacin, can cause a severe intestinal infection. Persistent or worsening diarrhea — even weeks after finishing the course — warrants a call to your doctor.
• Aortic aneurysm risk: Fluoroquinolones have been associated with an increased risk of aortic aneurysm or dissection (a dangerous tear in the body's largest artery). Seek care for sudden, severe chest or back pain.
• Blood sugar swings: Diabetic patients taking insulin or oral diabetes medications may experience dangerous drops or spikes in blood sugar. Monitor glucose carefully.

Ofloxacin oral tablets interact with several common drugs and supplements — tell your pharmacist and prescriber about everything you take:

• Antacids, sucralfate, iron, zinc, calcium, magnesium, and didanosine: These bind to ofloxacin in the gut and can dramatically reduce how much is absorbed. Separate these by at least 2 hours before or after taking ofloxacin.
• Theophylline: Ofloxacin can raise blood levels of theophylline (an asthma/COPD medication), increasing the risk of serious side effects including seizures. Blood levels should be monitored.
• Warfarin: Ofloxacin may enhance the blood-thinning effect of warfarin, raising the risk of bleeding. Clotting time should be monitored closely.
• NSAIDs (e.g., ibuprofen, naproxen): Combining these with ofloxacin may increase seizure risk.
• Insulin or oral diabetes medications (e.g., glyburide): Blood sugar can swing unpredictably — both dangerously low and dangerously high. Monitor carefully.
• Cyclosporine and drugs metabolized by the liver's cytochrome P450 system: Ofloxacin may affect how quickly these drugs are cleared, potentially raising their levels and side effects.
• Cimetidine: May slow ofloxacin clearance, though this specific interaction hasn't been fully studied.

This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.

• Do not take ofloxacin if you have a known allergy to ofloxacin, any quinolone antibiotic, or any component of the product
• Do not use the oral form if you have myasthenia gravis — it can cause life-threatening worsening of muscle weakness
• Tell your doctor about any history of tendon problems, tendinitis, or tendon rupture
• Tell your doctor if you have kidney disease — oral dosing requires adjustment when kidney function is reduced
• Tell your doctor about any seizure disorder, brain condition, or history of increased pressure in the brain
• Tell your doctor if you have or are at risk for aortic aneurysm — use the oral form only if no alternatives exist
• Older adults (especially over 60) are at higher risk for tendon rupture; caution is especially important when also taking corticosteroids
• The safety of oral ofloxacin has not been established in people under 18 years of age, during pregnancy, or while breastfeeding — discuss the risks carefully with your prescriber
• People with diabetes taking insulin or oral blood sugar medications should monitor glucose closely during treatment

There is limited information on ofloxacin overdose. In one reported case, a person who received too much intravenous ofloxacin developed drowsiness, nausea, dizziness, facial numbness and swelling, slurred speech, and disorientation — most symptoms resolved within an hour of stopping the infusion, and dizziness cleared within about 9 hours.

If an overdose is suspected, empty the stomach if appropriate and keep the person well hydrated under medical supervision. Ofloxacin is not effectively removed by dialysis.

Ofloxacin kills bacteria by interfering with enzymes (DNA gyrase and topoisomerase IV) that bacteria need to manage and replicate their DNA. Without these enzymes working properly, bacterial DNA breaks down and the bacteria cannot survive or reproduce. This bactericidal (bacteria-killing) action is effective against a broad range of gram-positive and gram-negative organisms, including some that are difficult to treat with other antibiotic classes.

When taken by mouth, ofloxacin tablets are almost completely absorbed (about 98%) and reach peak blood levels within 1–2 hours. Food doesn't reduce absorption but may slow the time to peak levels slightly. The drug distributes widely into body tissues — including lung, skin, prostate, and cervix — reaching concentrations close to those in the blood. Between 65–80% of an oral dose is excreted unchanged in the urine within 48 hours, making the kidneys the primary route of elimination; patients with reduced kidney function need dose adjustments. Ofloxacin has a working half-life (the time for the body to clear half the drug) of roughly 4–9 hours with normal kidney function, and it is only minimally broken down by the liver.

When used as ear drops, the drug is absorbed in very small amounts into the bloodstream — serum levels are far lower than with oral or intravenous use, which is why systemic side effects are much less of a concern with the otic form. High concentrations are achieved locally in the ear canal and middle ear fluid, where they are needed to fight infection.

Store at 20° to 25°C (68° to 77°F) .