Correction to: Communicating Adverse Drug Reaction Insights Through Patient Organizations: Experiences from a Pilot Study in the Netherlands.

The article "Communicating Adverse Drug Reaction Insights Through Patient Organizations: Experiences from a Pilot Study in the Netherlands", written by Linda Härmark, Gerda Weits, Rietje Meijer, Federica Santoro, G. Niklas Norén, Florence van Hunsel, was originally published electronically on 16 May 2020 without open access.

Communicating Adverse Drug Reaction Insights Through Patient Organizations: Experiences from a Pilot Study in the Netherlands.

INTRODUCTION: To improve therapeutic decision making, it is crucial that information regarding adverse drug reactions reaches patients. It is not enough to disseminate such findings through regulatory and scientific channels; targeted efforts to reach patients are necessary. One possible avenue is to collaborate with patient organizations. OBJECTIVES: The aim of this pilot study was to explore how adverse drug reactions can be communicated through patient organizations. METHODS: A text describing a signal of levothyroxine and panic attacks was tailored to patients' needs, in terms of language, style and content, with emphasis placed on what to do when experiencing the symptoms described. The signal was communicated via the Dutch thyroid organization's digital newsletter, social media channels, website and print magazine. RESULTS: The digital newsletter was distributed to around 5000 subscribers. On Facebook, 13,820 people viewed the message, with 2346 clicks in the message, indicating an intention to read the whole post. The interactions on social media were positive, and the tone was respectful. CONCLUSION: Patient organizations can help enable effective communication of adverse drug reactions to a relevant audience. The social media post generated more engagement than other communications from the patient organization, indicating a strong interest in this information. The additional patient experiences that were shared in the comments on social media further strengthened the original signal and its relevance to patients, creating an interesting feedback loop. The favourable experiences in this study support further consideration and exploration of this approach to communicate adverse drug reactions to patients.

Impact of a Forced Dose-Equivalent Levothyroxine Brand Switch on Plasma Thyrotropin: A Cohort Study.

Background: Patients with primary hypothyroidism are treated with levothyroxine (LT4) to normalize their serum thyrotropin (TSH). Finding the optimal dosage is a long-lasting process, and a small change can have major impact. Currently, limited data are available on the impact of dose-equivalent substitution between brands. This study aimed to determine the effect of the shortage of the LT4 brand Thyrax® in the Netherlands and the resulting dose-equivalent switch to another brand on plasma TSH concentrations in a large cohort of patients. Methods: Observational cohort study. Two registries representative for the Dutch population containing prescription and laboratory test data: the Nivel Primary Care Database and the PHARMO Database Network. Patients using at least 25 µg Thyrax daily for one year or longer were included. Two cohorts were formed: a switch cohort consisting of patients who switched from Thyrax to an alternative brand, and a Thyrax cohort including patients who continued to use Thyrax. Patients in the switch cohort did switch from Thyrax to a different brand of LT4 in 2016 and had two consecutive TSH measurements on the same dose of LT4, one before and one 6 weeks after the switch. Patients in the Thyrax cohort had two consecutive TSH measurements on the same dose of Thyrax that were 6 weeks apart. Results: In the Thyrax cohort, 19% of euthyroid patients using ≤100 µg had a TSH level outside the reference range at the subsequent measurement compared with 24% in the switch cohort (p < 0.0001). For patients using >100 µg Thyrax, these figures were 24% and 63%, respectively (p < 0.0001). Furthermore, patients using >50 µg Thyrax were four to five times more likely to become hyperthyroid after a dose-equivalent switch to a different brand compared with patients who stayed on Thyrax. Conclusions: In euthyroid patients continuing the LT4 product Thyrax at the same dose, TSH was out of range in 19-24% at least 6 weeks later. A dose-equivalent switch from Thyrax to other LT4 brands induced biochemical signs of overdosing in an even larger proportion (24-63%) of patients. The results indicate that a dose-equivalent LT4 brand switch may necessitate a dose adjustment in a large number of patients.