Grepafloxacin
Grepafloxacin is a fluoroquinolone antibiotic that was used to treat various bacterial infections, including respiratory tract infections and urinary tract infections. It was withdrawn from the market in 1999 due to concerns about cardiac side effects, particularly QT prolongation. This medication works by inhibiting bacterial DNA gyrase and topoisomerase IV enzymes, which are essential for bacterial DNA replication.
Grepafloxacin is a discontinued fluoroquinolone antibiotic that was used for bacterial infections but was withdrawn due to cardiac safety concerns.
Key facts at a glance
- ATC
- J01MA11
- RxNorm
- 83719
- Generic
- Grepafloxacin
- Class
- atc-j01
- Brands
- —
- Availability
- rx
- Lactation
- unknown
- Routes
- oral
- Forms
- tablet
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 500mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 250mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 400mg daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
8 groupspregnancy
first trimesteravoid use
avoid use during pregnancy unless benefits outweigh risks
regular fetal monitoring
Use of this medication in this population requires careful consideration of risks and benefits.
pregnancy
second trimesteravoid use
avoid use during pregnancy unless benefits outweigh risks
regular fetal monitoring
Use of this medication in this population requires careful consideration of risks and benefits.
pregnancy
third trimesteravoid use
avoid use during pregnancy unless benefits outweigh risks
regular fetal monitoring
Use of this medication in this population requires careful consideration of risks and benefits.
lactation
breastfeedingavoid use
do not use during breastfeeding due to excretion in breast milk
monitor infant for adverse effects
Use of this medication in this population requires careful consideration of risks and benefits.
pediatric_age
children under 18avoid use
avoid use in pediatric patients due to risk of cartilage damage
monitor for musculoskeletal effects
Use of this medication in this population requires careful consideration of risks and benefits.
geriatric
elderly 65 plusreduce dose and monitor closely
use with caution due to increased risk of QT prolongation and cardiac arrhythmias
monitor ECG, renal function, and for signs of cardiac toxicity
Use with caution and monitor for adverse effects.
renal_impairment
severe renal impairmentdose reduction required
reduce dose in patients with CrCl less than 50 mL/min
monitor renal function and adjust dose accordingly
Use with caution and monitor for adverse effects.
hepatic_impairment
severe hepatic impairmentuse with caution
use with caution in patients with hepatic impairment due to hepatic metabolism
monitor liver function tests
Use with caution and monitor for adverse effects.
Statistics and clinical data
Market status
Grepafloxacin was withdrawn due to safety concerns
Drug class
Antibiotic class information
Safety concern
Primary reason for market withdrawal
FDA approval year
Original FDA approval date
Grepafloxacin was indicated for the treatment of respiratory tract infections (including pneumonia and bronchitis), urinary tract infections, and other bacterial infections caused by susceptible organisms.
As a fluoroquinolone, grepafloxacin inhibits bacterial DNA gyrase and topoisomerase IV enzymes, which are critical for bacterial DNA replication, transcription, and repair, effectively killing susceptible bacteria.
Grepafloxacin was withdrawn from the global market in 1999 due to reports of serious cardiac arrhythmias associated with QT prolongation. It should not be used in patients with known QT prolongation, those taking antiarrhythmic drugs, or those with uncorrected electrolyte imbalances. Common side effects included nausea, diarrhea, headache, and dizziness.
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 24, 2026. · Read our editorial policy