Levofloxacin

Oral Antibiotics

Drug class: Fluoroquinolone; Quinolone antibiotic, belonging to the fluoroquinolone.

Levofloxacin (CRAVIT)（中文：左氧氟沙星）

Pronunciation

Levofloxacin 250mg

Common Strengths

• Tablet: 100 mg, 250 mg and 500 mg
• Infusion: 500 mg/100 mL
• Eye-drops 0.5% 5mL

Drug Trade Names

Cravit

Drug Usage

Levofloxacin is a broad-spectrum antibiotic belonging to the fluoroquinolone drug class. It is primarily used to treat various bacterial infections and is known for its effectiveness against both gram-positive and gram-negative bacterial.

Levofloxacin is indicated for the treatment of various infection, including:

• Respiratory tract infections (e.g. pneumonia, bronchitis)
• Urinary tract infections (UTIs)
• Skin and soft tissue infections
• Prostatitis
• Inhalational anthrax and plague (as part of post-exposure prophylaxis)

Mechanism of Action

Levofloxacin inhibits bacterial DNA synthesis by inhibiting DNA gyrase and topoisomerase IV, which are crucial for DNA replication and repair. This leads to bacterial cell death.

Route of Administration

Levofloxacin can be administered via:

• Oral tablets
• Intravenous (IV) infusion
• Eye drops

Dosages

Typical dosages vary based on the condition being treated and the patient's renal function. General recommendations include:

• Normal Adults: 500 mg once daily for most infections.

For patients with renal impairment, dosing adjustments are based on estimated glomerular filtration rate (eGFR):

• eGFR >50 mL/min: Standard dosing.
• eGFR 20-50 mL/min: 250 mg once daily
• eGFR <20 mL/min: Use with caution; consult a healthcare provider.

Side Effects

Frequency	Adverse reactions
Common Side Effects	Nausea
	Diarrhea
	Headache
	Dizziness
Serious Side Effects	Tendon rupture or inflammation
	Peripheral neuropathy
	QT interval prolongation (risk of serious heart arrhythmias)
	Severe mood changes or seizures

Cautions: Due to potentially serious side effects associated with levofloxacin such as tendon damage and QT interval prolongation, it is reserved for cases where other antibiotics are ineffective or inappropriate.

Pharmacokinetics

The elimination half-life is about 6.9 hours. The onset of action typically occurs within hours, with a duration of effect lasting up to 24 hours after administration.

Drug Precautions

Pregnancy

Levofloxacin is not recommended during pregnancy due to potential risk to the fetus.

Breastfeeding

It is unclear if levofloxacin is safe during breastfeeding; caution is advised.

Children and Elderly

Not generally recommended for children under 18 due to risks of joint issues. Use in the elderly should be cautions due to increased risk of side effects.

Drug Monitoring Items

Regular monitoring for:

• Signs of tendon damage: There is a risk of tendon inflammation and rupture, particularly in older adults or those on corticosteroids. Patients should be educated about signs of tendinitis.
• Peripheral neuropathy: Caution should be exercised in patients with a history of seizures or central nervous system disorder due to the potential for convulsions.

Drug Interactions

Some of the most notable interactions include:

• Antacids and Supplements: Antacids containing aluminum, magnesium, or calcium, as well as iron and zinc supplements, can significantly reduce the absorption of levofloxacin. It is recommended to take these agents at least two hours before or after levofloxacin to avoid interactions.
• Antidiabetic Medications: Levofloxacin can cause fluctuations in blood sugar levels, leading to both hyperglycemia and hypoglycemia. Patients taking diabetes medications such as insulin or sulfonylureas should monitor their blood glucose levels closely while on levofloxacin.
• NSAIDs (Non-Steroidal Anti-Inflammatory Drugs): Concurrent use of NSAIDs may increase the risk of central nervous system (CNS) stimulation and seizure.
• Warfarin: Levofloxacin may enhance the effects of warfarin, leading to an increased risk of bleeding. Monitoring prothrombin time and INR is advised when these drugs are used together.
• QT-Prolonging Agents: Levofloxacin can cause QT interval prolongation, which increases the risk of serious heart arrhythmias. Medications like sotalol, amiodarone, and certain antipsychotics should be avoided in combination with levofloxacin.

FAQ

How Should I Take the Tablet?

Take levofloxacin by mouth or without food, usually once daily.

What Should I Avoid while Taking?

Avoid antacids, supplements containing iron or zinc, and excessive sunlight exposure due to increased risk of sunburn.

What Happens If I Miss a dose?

If you miss a dose, take it as soon as remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule. Do not double up on doses.