From the Guidelines
Levofloxacin is available in both oral and intravenous (IV) formulations, with the oral form being suitable for outpatient use and the IV form primarily used in hospital settings for severe cases or when immediate high blood levels of the antibiotic are required. The choice between oral and IV levofloxacin depends on the patient's condition, the severity of the infection, and the healthcare provider's judgment. According to the most recent and highest quality study available, 1, levofloxacin can be administered as 750 mg every 24 hours either IV or orally, indicating that both routes are effective for treating certain infections. This flexibility is crucial in clinical practice, allowing for tailored treatment approaches based on individual patient needs. For instance, patients who are severely ill or unable to take oral medications may initially receive the IV form, and then switch to the oral form as their condition improves, ensuring continuity of care and optimizing treatment outcomes. Both formulations contain the same active ingredient and are equally effective when used appropriately, though they differ in how quickly the medication reaches the bloodstream. The oral form is generally more convenient for outpatient use, while the IV form is primarily used in hospital settings for more severe cases or specific clinical scenarios where rapid achievement of therapeutic drug levels is necessary.
From the FDA Drug Label
The plasma concentration profile of levofloxacin after IV administration is similar and comparable in extent of exposure (AUC) to that observed for levofloxacin tablets when equal doses (mg/mg) are administered. Therefore, the oral and IV routes of administration can be considered interchangeable [see Figure 2 and Figure 3]. Following a single intravenous dose of levofloxacin to healthy volunteers, the mean ± SD peak plasma concentration attained was 6.2 ± 1 mcg/mL after a 500 mg dose infused over 60 minutes and 11. 5 ± 4 mcg/mL after a 750 mg dose infused over 90 minutes. Levofloxacin oral solution and tablet formulations are bioequivalent. Levofloxacin pharmacokinetics are linear and predictable after single and multiple oral or IV dosing regimens.
Levofloxacin can be administered both orally and intravenously. The oral and IV routes of administration are considered interchangeable, with similar plasma concentration profiles and bioequivalence between oral solution and tablet formulations 2.
From the Research
Administration Routes of Levofloxacin
Bioavailability and Pharmacokinetics
- The oral bioavailability of levofloxacin approaches 100% and is not significantly affected by food intake 4.
- Levofloxacin has a high volume of distribution and penetrates well into most body tissues and fluids, with the exception of the cerebrospinal fluid 4.
- The plasma elimination half-life of levofloxacin ranges from 6 to 8 hours in individuals with normal renal function 4.
Switching Between Oral and IV Routes
- Patients can be switched from IV to oral levofloxacin without dosage adjustment due to its high oral bioavailability 3, 6, 7.
- The pharmacokinetics of levofloxacin are similar during multiple-dose regimens to those following single doses, allowing for flexible treatment regimens 4.
Clinical Applications
- Levofloxacin is effective in the treatment of various infections, including community-acquired pneumonia, acute bacterial sinusitis, complicated urinary tract infections, and acute pyelonephritis 3, 5, 6, 7.
- The high-dose, short-course regimen of levofloxacin (750 mg once daily for 5 days) is approved for use in the US for certain infections and has been shown to be noninferior to longer treatment regimens 5.