Usage
Lomefloxacin is prescribed for mild to moderate bacterial infections, including lower respiratory tract infections (such as acute bacterial exacerbations of chronic bronchitis) and urinary tract infections (UTIs) (such as uncomplicated cystitis and complicated UTIs). It has also been used for prophylaxis of surgical site infections, particularly transrectal prostate biopsy and transurethral surgical procedures. As of 2019-03-21, Lomefloxacin is no longer available in the US market.
Lomefloxacin is classified as a fluoroquinolone antibiotic.
It inhibits bacterial DNA gyrase and topoisomerase IV. These enzymes are essential for bacterial DNA replication, transcription, repair, and recombination. By inhibiting these enzymes, lomefloxacin disrupts bacterial DNA synthesis and leads to bacterial cell death.
Alternate Names
Lomefloxacin hydrochloride is also known by the brand name Maxaquin (no longer marketed in the US, as of 2019-03-21).
How It Works
Pharmacodynamics: Lomefloxacin exerts its bactericidal effect by inhibiting bacterial DNA gyrase and topoisomerase IV. This inhibition leads to the disruption of bacterial DNA replication and transcription, ultimately resulting in bacterial cell death.
Pharmacokinetics:
- Absorption: Lomefloxacin is rapidly and almost completely absorbed after oral administration, with peak plasma concentrations reached in 1-1.5 hours. Food may delay absorption.
- Distribution: It is widely distributed throughout the body.
- Metabolism: Lomefloxacin is minimally metabolized. Approximately 65% is excreted in the urine as the parent drug and 9% as the glucuronide metabolite.
- Elimination: Primarily eliminated by renal excretion. Virtually complete within 72 hours after cessation of dosing.
Mode of Action: Lomefloxacin binds to the A-subunit of bacterial DNA gyrase (topoisomerase II). This binding forms a stable complex that impairs enzyme function, resulting in the rapid killing of susceptible bacteria.
Elimination Pathways: Primarily renal excretion (approximately 65% as unchanged drug and 9% as glucuronide metabolite).
Dosage
Standard Dosage
Adults:
The recommended daily dose of lomefloxacin is 400 mg once daily. The duration of treatment depends on the type and severity of the infection: 3 days for uncomplicated cystitis caused by E. coli in females, 10 days for acute bacterial exacerbations of chronic bronchitis or uncomplicated cystitis caused by other susceptible pathogens, and 14 days for complicated UTIs. For surgical prophylaxis, a single dose of 400 mg is given 1-6 hours before the procedure.
Children:
Lomefloxacin is contraindicated in children and adolescents under 18 years of age due to the risk of arthropathy and cartilage damage.
Special Cases:
- Elderly Patients: No dosage adjustment is required for elderly patients with normal renal function (creatinine clearance ≥ 40 mL/min/1.73 m²).
- Patients with Renal Impairment: Dosage adjustment is required. For creatinine clearance between 10 and 40 mL/min/1.73 m² and hemodialysis patients, an initial loading dose of 400 mg followed by a maintenance dose of 200 mg once daily is recommended.
- Patients with Hepatic Dysfunction: Dose adjustment may be necessary based on the degree of renal function.
- Patients with Comorbid Conditions: Use with caution in patients with CNS disorders (e.g., epilepsy) or QT prolongation.
Clinical Use Cases
Lomefloxacin is no longer indicated for routine use in the clinical situations mentioned below due to concerns about side effects and the availability of safer alternatives. Historically, it was used in: Intubation, surgical procedures (prophylaxis), mechanical ventilation, intensive care unit (ICU) use, and emergency situations. These are no longer recommended clinical applications.
Dosage Adjustments
Dose adjustments are needed for patients with renal impairment, as described above. Monitor patients for adverse reactions, particularly in elderly patients with declining renal function.
Side Effects
Common Side Effects
Nausea, vomiting, diarrhea, headache, dizziness, drowsiness, tinnitus, photosensitivity, insomnia, indigestion, abdominal pain.
Rare but Serious Side Effects
Allergic reactions (difficulty breathing, swelling), seizures, confusion, hallucinations, liver damage (jaundice, fatigue), muscle or joint pain, peripheral neuropathy, tendon rupture, QT interval prolongation/torsades de pointes.
Long-Term Effects
Peripheral neuropathy, tendonitis.
Adverse Drug Reactions (ADR)
Allergic reactions, seizures, liver damage, QT prolongation, torsades de pointes, severe photosensitivity reactions.
Contraindications
Hypersensitivity to lomefloxacin or other quinolones, children under 18, pregnancy, lactation.
Drug Interactions
Antacids containing magnesium or aluminum, sucralfate, iron or zinc supplements, cimetidine, probenecid, cyclosporine, insulin or oral diabetes medications, NSAIDs, Class IA (quinidine, procainamide) or Class III (amiodarone, sotalol) antiarrhythmics, theophylline, caffeine, warfarin, and many other drugs. Alcohol interaction is unknown. Refer to a comprehensive drug interaction database for a complete list.
Pregnancy and Breastfeeding
Lomefloxacin is contraindicated in pregnancy (FDA Pregnancy Category C) due to potential risks to the fetus, including cartilage damage and arthropathies.
Lomefloxacin is contraindicated during breastfeeding due to unknown safety profile.
Drug Profile Summary
- Mechanism of Action: Inhibits bacterial DNA gyrase and topoisomerase IV, disrupting DNA synthesis.
- Side Effects: Nausea, vomiting, diarrhea, headache, dizziness, photosensitivity; rarely seizures, allergic reactions, liver damage, tendon rupture, QT prolongation.
- Contraindications: Hypersensitivity, age <18, pregnancy, lactation.
- Drug Interactions: Numerous; consult a drug interaction database.
- Pregnancy & Breastfeeding: Contraindicated.
- Dosage: Adults: 400 mg once daily; adjust for renal impairment.
- Monitoring Parameters: Renal function, liver function tests, ECG (for QT prolongation), signs of tendonitis or peripheral neuropathy.
Popular Combinations
Lomefloxacin is generally not used in combination with other drugs due to its potential for numerous drug interactions.
Precautions
General precautions: Assess renal and hepatic function, history of seizures or QT prolongation. Photosensitivity precautions are essential.
Specific Populations: Contraindicated in pregnancy, lactation, and children under 18. Elderly patients may require closer monitoring for adverse reactions.
Lifestyle Considerations: Avoid excessive sun exposure. Alcohol interaction is unknown. Advise patients against driving or operating machinery if dizziness or lightheadedness occurs.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Lomefloxacin?
A: Adults: 400 mg once daily, adjust for renal impairment. Pediatric use is contraindicated.
Q2: What are the most common side effects of Lomefloxacin?
A: Nausea, vomiting, diarrhea, headache, dizziness, photosensitivity.
Q3: What are the serious side effects of Lomefloxacin?
A: Seizures, allergic reactions, liver damage, QT prolongation/torsades de pointes, tendon rupture, peripheral neuropathy.
Q4: Is Lomefloxacin safe to use during pregnancy or breastfeeding?
A: No, Lomefloxacin is contraindicated during pregnancy and breastfeeding.
Q5: Can Lomefloxacin be used in children?
A: No, Lomefloxacin is contraindicated in children under 18 years old.
Q6: What are the drug interactions with Lomefloxacin?
A: Lomefloxacin has numerous drug interactions. Significant interactions include antacids, sucralfate, mineral supplements, some other antibiotics, certain antiarrhythmics, theophylline. Consult a comprehensive drug interaction database for a complete list.
Q7: What precautions should be taken when prescribing Lomefloxacin?
A: Assess renal and hepatic function. Advise patients regarding photosensitivity and potential CNS side effects. Monitor for tendonitis and QT prolongation.
Q8: What is the mechanism of action of Lomefloxacin?
A: Lomefloxacin inhibits bacterial DNA gyrase and topoisomerase IV, thereby disrupting DNA synthesis.
Q9. What should patients do if they miss a dose of Lomefloxacin?
A: Patients should take the missed dose as soon as they remember, unless it is almost time for the next dose. They should not double the dose to catch up.
