Moderate
Probable
الوصف
Ciprofloxacin can reduce levothyroxine absorption through complex formation and potential effects on gut motility and transport, risking under-replacement in hypothyroid patients on long courses.
الآلية
In vitro and case data suggest ciprofloxacin may form metal ion-mediated complexes with levothyroxine in the GI tract, impairing absorption. Ciprofloxacin may also alter CYP enzymes relevant to T4 deiodination.
الأهمية السريرية
Case reports document elevated TSH and symptom recurrence in hypothyroid patients during ciprofloxacin courses; the effect is more pronounced with simultaneous administration.
التدبير
Administer levothyroxine at least 4 hours apart from ciprofloxacin; monitor TSH if a prolonged ciprofloxacin course (>7 days) is required; dose adjustment may be needed.