Bethkis (tobramycin) is an aminoglycoside antibiotic. It is used to treat or prevent certain kinds of bacterial infections in the lungs. It will not work for colds, flu, or other viral infections. This drug is less popular than comparable drugs. There is currently no generic alternative for Bethkis. It may be covered by Medicare and insurance plans, but some pharmacy coupons or cash prices may be lower. With the Patient Assistance Program from HealthWell Foundation, contact the program to see how they can financially help you out.