<p>Increased risk of hypokalamia if high doses of corticosteroids, diuretics (acetazalamide, loop diuretics and thiazides) or theophylline given with high doses of ritodrine. A sufficient time interval should elapse prior to administration of another sympathomimetic drug. &beta;&ndash;adrenergic blocking drugs inhibit its action; coadministraton of these drugs should, therefore, be avoided. With anesthetics used in surgery, the possibility that hypotensive effects may be potentiated should be considered.</p>