Brand and generic use of inhalation medication and frequency of switching in children and adults: A population-based cohort study

Abstract

Background: The expiration of patents of brand inhalation medications and the ongoing pressure on healthcare budgets resulted in a growing market for generics. Aim: To study the use of brand and generic inhalation medication and the frequency of switching between brand and generic and between devices. In addition, we investigated whether switching affected adherence. Methods: From dispensing data from the Dutch PHARMO Database Network a cohort aged ࣙ 5 years, using ࣙ 1 year of inhalation medication between 2003 and 2012 was selected. Switching was defined as changing from brand to generic or vice versa. In addition, we studied change in aerosol delivery device type (e.g., DPI, pMDI, and nebulizers). Adherence was calculated using the medication possession ratio (MPR). Results: The total cohort comprised 70,053 patients with 1,604,488 dispensations. Per calendar year, 5% switched between brand and generic inhalation medication and 5% switched between devices. Median MPRs over the first 12 months ranged between 33 and 55%. Median MPR over the total period was lower after switch from brand to generic and vice versa for formoterol (44.5 vs. 42.1 and 63.5 vs. 53.8) and beclomethasone (93.8 vs. 59.8 and 81.3 vs. 55.9). Conclusion: Per year, switching between brand and generic inhalation medication was limited to 5% of the patients, switching between device types was observed in 5% as well. Adherence to both generic and brand inhalation medication was low. Effect of switching on adherence was contradictory; depending on time period, medication and type, and direction of switching. Further research on reasons for switching and potential impact on clinical outcomes is warranted.

Quantification of Adverse Drug Reactions Related to Drug Switches in The Netherlands

“…In a study on the frequency of switching and adherence of inhalation medication, a yearly percentage switch of ~ 5% of total users was identified. 21 This is low compared with our results, perhaps because multiple switches per patient and switches between generics were not accounted for in that publication. We are unaware of other literature references on drug switch frequencies.…”

General Practitioner Use of Generically Substitutable Inhaler Devices and the Impact of Training on Device Mastery and Maintenance of Correct Inhaler Technique

“…While the health economic benefits to individuals and societies associated with generic substitutes are widely accepted [8,9], ongoing debate surrounds the impact on respiratory health outcomes. While some feel that generic substitution will cause reduced adherence due to patient confusion and dislike of physical attributes of a new inhaler device [3,10,11], patients who have switched appear to be equally non-adherent to their generic medicines as to their branded options [8]. It is widely agreed that if generic substitution is to occur, the best outcomes require the prescriber to obtain consent from the patient and demonstrate correct inhaler technique of the generic inhaler device [3,8,12,13].…”

“…While some feel that generic substitution will cause reduced adherence due to patient confusion and dislike of physical attributes of a new inhaler device [3,10,11], patients who have switched appear to be equally non-adherent to their generic medicines as to their branded options [8]. It is widely agreed that if generic substitution is to occur, the best outcomes require the prescriber to obtain consent from the patient and demonstrate correct inhaler technique of the generic inhaler device [3,8,12,13]. Although substitution can also occur within the pharmacy at the point of dispensing [14], the success of generic substitution of inhalers is dependent on the prescriber obtaining consent and their ability to be able to demonstrate its correct use [3,13].…”

“…It compromises disease control [22,24] and is associated with an increase in the economic burden of disease management [3]; yet incorrect inhaler use continues to remain an issue in clinical practice [25]. Global experts stress the importance of inhaler technique in the management of chronic respiratory disease [6] and the updated Australian Asthma Management Guidelines and the Global Initiative for Asthma (GINA) Strategy identify inhaler technique as one of the core targets for assessment and intervention for people with poorly controlled disease [7,8,26]. Given that approximately 50% of people with asthma in Australia do not have well-controlled disease [27] and up to 80% have poor inhaler technique [16], it highlights the importance/ need for prescribers to be actively engaged in IT training, including those inhalers for which there are generic substitutions [27,28].…”

Cost saving of switching to equivalent inhalers and its effect on health outcomes

“…However, trials have optimised participant's inhaler technique and encouraged high levels of adherence, which does not reflect everyday clinical practice and most respiratory patients do not meet typical trial eligibility criteria (5,6). There is a paucity of real-world studies assessing health outcomes after switching patients to an equivalent inhaler, furthermore, no study has specifically addressed switching for financial gain (7)(8)(9)(10)(11).…”