Drug Interactions between metrizamide and moxifloxacin / triamcinolone

CONTRAINDICATED: Coadministration of corticosteroids with iodinated contrast media by the intrathecal route may be associated with a high incidence of radiographic arachnoiditis. Meningitis and seizures may also occur.

MANAGEMENT: Intrathecal coadministration of corticosteroids with iodinated contrast media is considered contraindicated.

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: Intrathecal administration of iodinated contrast media may induce seizures. Although clinical data are generally lacking, there may be a theoretical risk of increased seizure potential when used with selective serotonin reuptake inhibitors (SSRI antidepressants or anorectics), monoamine oxidase inhibitors, neuroleptic agents, central nervous system stimulants, opioids, tricyclic antidepressants, other tricyclic compounds (e.g., cyclobenzaprine, phenothiazines), and/or any substance that can reduce the seizure threshold (e.g., carbapenems, cholinergic agents, fluoroquinolones, interferons, chloroquine, mefloquine, lindane, theophylline). These agents are often individually epileptogenic and may have additive effects when combined.

MANAGEMENT: Drugs that can lower the seizure threshold should preferably be withheld for at least 48 hours prior to and 24 hours following intrathecal administration of iodinated contrast media, provided that temporary interruption of therapy does not pose an undue risk to the patient. Otherwise, close monitoring is advised during and after contrast administration. The manufacturers typically recommend avoiding concomitant administration of phenothiazines (including those used for their antihistamine properties), monoamine oxidase inhibitors, tricyclic antidepressants, central nervous system stimulants, and psychoactive drugs.