Levofloxacin: what it treats, how to take it, side effects
Last updated September 3, 2026.
Levofloxacin is a fluoroquinolone antibiotic - it kills the bacteria behind serious infections. It is powerful, and it is held in reserve: MedlinePlus says it should not be used for bronchitis and certain urinary tract infections when other treatment options exist, because its boxed warnings are real.
What does it treat?
Pneumonia and kidney, prostate, and skin infections; prevention of anthrax after exposure; and treatment and prevention of plague. It is also used for bronchitis, sinus infections, and urinary tract infections only when other options are not available. It kills bacteria; it does nothing for viruses like colds and flu.
How do you take it?
Once a day, same time every day. The tablet goes with or without food; the solution goes 1 hour before or 2 hours after eating. Finish the whole prescription even when you feel better - with one exception written into the instructions: if you experience any of the serious side effects in the warning sections, stop taking levofloxacin and call your doctor immediately. That stop-then-call rule is unusual for an antibiotic, and it is there for a reason. Missed dose: take it when you remember unless the next one is close; never double up.
Side effects to know
- Common: nausea, vomiting, diarrhea, stomach pain, constipation, heartburn, and vaginal itching or discharge.
- Serious - the boxed warnings: tendon damage - pain, swelling, tenderness, stiffness, or trouble moving a muscle means stop, rest, and call immediately; a snap or pop, bruising, or inability to bear weight is tendon rupture, an emergency. Nerve damage - numbness, tingling, pain, burning, or weakness in the arms or legs, which may not go away even after stopping. And brain and nervous system effects - seizures, tremors, persistent headaches, nightmares, hallucinations, anxiety, depression, confusion, or thoughts of hurting yourself, possible after the very first dose. Also serious: severe watery or bloody diarrhea up to 2 months or more after treatment, rash, hives, peeling skin, and fever.
Who should not take it?
Myasthenia gravis heads the list - levofloxacin can worsen the muscle weakness to the point of breathing difficulty; MedlinePlus says your doctor may rule it out. The tendon risk runs highest over 60, in transplant recipients, with kidney disease, joint or tendon disorders like rheumatoid arthritis, regular physical activity, and steroid use. Flag past peripheral neuropathy, seizures, stroke, and kidney disease. If you become pregnant, call your doctor.
When is it an emergency?
A tendon snap or pop with inability to bear weight, a seizure, or trouble breathing is a 911 call. Hallucinations or thoughts of harming or killing yourself mean stopping the drug and getting immediate care - and the 988 Suicide and Crisis Lifeline (call or text 988) is there anytime. For an overdose, call Poison Control at 1-800-222-1222. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
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Common questions
Why did my doctor say levofloxacin is a last-resort antibiotic?
Because its risks are bigger than most antibiotics'. MedlinePlus says it should not be used for bronchitis and certain urinary tract infections if other treatment options are available - the boxed warnings (tendon rupture, nerve damage that may not go away, serious nervous-system effects) only make sense to accept when milder antibiotics cannot do the job. When it is prescribed, the infection earned it.
What is the tendon warning about levofloxacin?
Fluoroquinolones can weaken tendons - the Achilles most famously - during treatment or for months after. MedlinePlus sets the action plainly: pain, swelling, tenderness, stiffness, or trouble moving a muscle means stop taking levofloxacin, rest, and call your doctor immediately. A snap or pop, bruising, or inability to bear weight is a rupture - emergency care. The risk runs highest over 60, with steroids, and with transplants.
Can levofloxacin really cause nerve damage?
Yes, and MedlinePlus says it may not go away even after you stop. Numbness, tingling, pain, burning, or weakness in the arms or legs, or changes in feeling touch, vibration, heat, or cold, means stop taking it and call your doctor immediately - it can start soon after the first doses, so do not push through those symptoms.
Why did levofloxacin give me nightmares and anxiety?
It can affect the brain and nervous system, sometimes after the first dose - MedlinePlus lists nightmares, restlessness, anxiety, depression, confusion, hallucinations, and thoughts of hurting yourself among the possible effects, and the rule is stop and call your doctor immediately. You are not imagining it, and you are not stuck with it. If dark thoughts ever show up, 988 (call or text) is there anytime.
Can I drink alcohol while taking levofloxacin?
Neither the label nor MedlinePlus gives levofloxacin-specific alcohol language. Alcohol adds dizziness and stomach upset on top of an antibiotic, and you are fighting an infection that needs rest and hydration. Skip it for the course - it is the easy call.
What happens if I miss a dose of levofloxacin?
Take it as soon as you remember, unless it is almost time for the next one - then skip it and never double up. With once-daily dosing, anchor it to a morning habit. The goal is steady levels through the whole course so no bacteria survive to regrow.