Drug Interaction Report

MONITOR CLOSELY: Concomitant administration of corticosteroids may potentiate the risk of tendinitis and tendon rupture associated with fluoroquinolone treatment. The mechanism is unknown. Tendinitis and tendon rupture have most frequently involved the Achilles tendon, although cases involving the rotator cuff (the shoulder), the hand, the biceps, and the thumb have also been reported. Some have required surgical repair or resulted in prolonged disability. Tendon rupture can occur during or up to several months after completion of fluoroquinolone therapy.

MANAGEMENT: Caution is recommended if fluoroquinolones are prescribed in combination with corticosteroids, particularly in patients with other concomitant risk factors (e.g., age over 60 years; recipient of kidney, heart, and/or lung transplant). Patients should be advised to stop taking the fluoroquinolone, avoid exercise and use of the affected area, and promptly contact their physician if they experience pain, swelling, or inflammation of a tendon. In general, fluoroquinolones should only be used to treat conditions that are proven or strongly suspected to be caused by bacteria and only if the benefits outweigh the risks.

GENERALLY AVOID: Urinary alkalinizers such as citrates may decrease the solubility of fluoroquinolones in the urine and increase the risk of crystalluria.

MANAGEMENT: Concomitant use should generally be avoided. Patients receiving this combination should be monitored for signs of renal toxicity and crystalluria.

Antacids and agents with acid-neutralizing effects may impair the oral absorption of dexamethasone, prednisolone, prednisone, and other orally administered corticosteroids, although data from published studies are somewhat conflicting. The mechanism of interaction and clinical significance are unknown. No particular intervention is necessary during concomitant therapy with these agents, but clinicians should be aware of the potential for interaction.