You should NOT shake which of the following dry powder inhalers before use?

The correct choice is the QVAR Redihaler, as it is designed to deliver medication in a specific manner that does not require shaking prior to use. Shaking it could potentially disrupt the flow of the aerosolized particles, which may lead to inconsistent dosing.

Unlike the QVAR Redihaler, other dry powder inhalers such as Advair Diskus, Symbicort, and the albuterol metered-dose inhaler (MDI) have different mechanisms or formulations that might benefit from shaking to ensure that the medication is properly mixed or aerosolized for effective administration. Therefore, it is crucial to follow specific instructions for each inhaler to maximize their efficacy and ensure that the patient receives the correct dosage.