There are other combination inhalers that can be used as an alternative to Seretide.
Seroflo and Combisal offer a cheaper alternative to Seretide but contain the same active ingredients: salmeterol and fluticasone
Symbicort is made by the same manufacturer as Seretide. It contains different active ingredients to Seretide, but works in a similar way. Symbicort is used less frequently than Seretide to achieve the same effects.