( 7.1 ) Tobramycin Inhalation Solution should not be administered concomitantly with ethacrynic acid, furosemide, urea, or intravenous mannitol. Therefore, Tobramycin Inhalation Solution should not be administered concomitantly with ethacrynic acid, furosemide, urea, or intravenous mannitol.
Source: FDA drug label - tobramycin inhalation solution