What are the contraindications for Levaquin (levofloxacin)?

Contraindications for Levaquin (Levofloxacin)

Levaquin (levofloxacin) is absolutely contraindicated in patients with known hypersensitivity to levofloxacin or other quinolone antibacterials, and in patients with myasthenia gravis due to risk of exacerbating muscle weakness. 1

Primary Contraindications

1. Hypersensitivity reactions:

   • Known allergy to levofloxacin
   • Known allergy to any quinolone antibacterial
   • Previous history of serious adverse reactions to fluoroquinolones

2. Myasthenia gravis:

   • Levofloxacin is contraindicated in patients with known history of myasthenia gravis due to risk of severe exacerbation 1

High-Risk Conditions (Use with Extreme Caution)

Tendon-Related Risks

• Age >60 years (significantly increased risk)
• Concomitant corticosteroid therapy
• Kidney, heart, or lung transplant recipients 1
• History of tendon disorders

Neurological Risks

• Known or suspected CNS disorders that predispose to seizures (e.g., severe cerebral arteriosclerosis or epilepsy) 2
• History of CNS reactions to fluoroquinolones

Cardiac Risks

• Known QT interval prolongation
• Uncorrected hypokalemia or hypomagnesemia
• Concurrent use of Class IA (e.g., quinidine, procainamide) or Class III (e.g., amiodarone, sotalol) antiarrhythmic agents 2

Pregnancy

• Levofloxacin should be avoided in pregnancy due to potential teratogenic effects 3

Dosage Adjustments Required

Renal Impairment

• Levofloxacin is primarily (80%) cleared by the kidneys 3
• Dosage adjustment is required if creatinine clearance is less than 50 ml/minute 3
• Recommended adjustment: 750-1,000 mg three times a week instead of daily dosing 3

Drug Interactions to Avoid

1. Medications containing divalent cations:

   • Antacids containing aluminum or magnesium
   • Iron supplements (ferrous sulfate)
   • These significantly decrease levofloxacin absorption 4
   • Administration must be separated by at least 2 hours from levofloxacin 3

2. QT-prolonging medications:

   • Class IA and Class III antiarrhythmics
   • Other medications known to prolong QT interval

Monitoring Requirements

• Renal function in elderly patients and those with known renal impairment
• Signs of tendinitis or tendon rupture, especially in high-risk patients
• CNS symptoms (confusion, dizziness, hallucinations) particularly in elderly patients
• QT interval in patients with risk factors for QT prolongation

Special Populations

Elderly Patients

• Higher risk for tendon disorders, CNS effects, and QT prolongation 2
• Require close monitoring for adverse effects that may be mistakenly attributed to aging (confusion, weakness, tremor) 2
• May require dosage adjustment based on decreased renal function

Children and Adolescents

• Long-term use (more than several weeks) not approved due to concerns about effects on bone and cartilage growth 3
• Consider only in cases of multidrug-resistant tuberculosis where benefits outweigh risks 3

Remember that levofloxacin carries a boxed warning regarding the risks of tendinitis and tendon rupture, which are increased in older patients, those on corticosteroids, and transplant recipients. Additionally, the risk of exacerbating muscle weakness in myasthenia gravis patients makes this an absolute contraindication 1.