<p><strong>With medicine</strong>: Anticoagulants (oral)- Due to potential inhibition of vitamin K activity by methimazole, the activity of oral anticoagulants (e.g., warfarin) may be increased; additional monitoring of PT/INR should be considered, especially before surgical procedures. &beta;-adrenergic blocking agents- Hyperthyroidism may cause an increased clearance of beta-blockers with a high extraction ratio. A dose reduction of beta-adrenergic blockers may be needed when a hyperthyroid patient becomes euthyroid. Digitalis glycosides- Serum digitalis levels may be increased when hyperthyroid patients on a stable digitalis glycoside regimen become euthyroid; a reduced dosage of digitalis glycosides may be needed. Theophylline- Theophylline clearance may decrease when hyperthyroid patients on a stable theophylline regimen become euthyroid; a reduced dose of theophylline may be needed.<br />
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<strong>With food</strong>: Always take at the same moment in regard to meals, food may affect absorption unpredictably.</p>