Drug Interactions between moxifloxacin / triamcinolone and smallpox vaccine

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: The administration of live virus smallpox vaccine during corticosteroid therapy may be associated with a risk of localized or disseminated infection due to enhanced replication of vaccine virus in the presence of diminished immune competence. Patients receiving high dosages of systemic corticosteroids (e.g., greater than 20 mg/day or 2 mg/kg/day of prednisone or equivalent for more than 2 weeks) and those who are systemically immunosuppressed due to long-term topical or aerosol use of corticosteroids may also have an increased risk of neurologic reactions to vaccines and decreased or suboptimal immunologic response due to antibody inhibition. The risk of ocular complications may be increased in patients who are using ophthalmic corticosteroids.

MANAGEMENT: Routine nonemergency smallpox vaccination is considered a relative contraindication in patients receiving immunosuppressive corticosteroid therapy or ophthalmic corticosteroids. Vaccination should be deferred until after such therapy is discontinued and immune function has been restored. The interval depends on the dosage, duration, and route of corticosteroid therapy administered, but may be at least 3 months in most cases of systemic corticosteroid use. In patients who have recently been vaccinated, high-dose corticosteroid therapy should not be initiated for at least 2 weeks. Household contacts of immunosuppressed patients should also not be vaccinated. However, there are no absolute contraindications to vaccination if a high-risk exposure has occurred. In an outbreak emergency, smallpox vaccine is generally recommended for all persons, regardless of medical conditions. The risk for experiencing serious complications from the vaccine should be weighed against the risk of acquiring a potentially fatal smallpox infection. Vaccines may generally be administered to patients receiving corticosteroids as replacement therapy (e.g., for Addison's disease).