An accessory (50, 80) is for application to the air inlet of a breath actuated inhaler (10). It has an assist chamber for holding a volume of air and a mechanical release system for expelling air from the assist chamber to the air inlet (19), at a rate sufficient to trigger a dose trigger mechanism (30) of the breath actuated inhaler. In this way, a user may use a breath actuated inhaler even if they do not have the ability to generate an inhalation suitable for activating the inhaler.
