Rx Update: September 2002
Mary Ross, R.Ph., M.B.A., Barbara Mutnick, R.Ph., M.H.P., Joan
Murhammer, R.Ph.
Peer Review Status: Internally Reviewed
Levofloxacin (Levaquin®), the primary fluroquinolone anti-infective at UIHC, is known to have decreased oral bioavailability when administered with products containing multivalent cations such as aluminum, calcium, magnesium, iron, and zinc. This drug interaction between levofloxacin and multivalent cations may lead to decreased effectiveness of oral levofloxacin.
Levofloxacin is capable of forming chelate complexes with metal ions that cause a reduction in oral bioavailability. However, it is possible to avoid this interaction by administering levofloxacin at least two hours before or two hours after the administration of products containing multivalent cations. This separation of medications is necessary to ensure that the patient is absorbing the proper amount of levofloxacin to attain adequate blood levels and eradicate the infection.
To ensure the effectiveness, appropriate administration times of oral levofloxacin with respect to concurrent cations must be employed. Levofloxacin should be administered at least two hours before or two hours after administration of products containing multivalent cations such as aluminum, calcium, magnesium, iron, and zinc. Examples of products containing multivalent cations are listed below.
UIHC Formulary Examples: